PRODUCING THE SAME

FIELD OF THE INVENTION

The invention pertains to an interlockable unit, wherein the interlockable unit a. is adapted and arranged to engage at least one other interlockable unit in an interlocking manner; b. comprises the following layers: i. a base layer, wherein the base layer comprises a plurality of polymer particles; ii. a further intermediate layer, wherein the further intermediate layer

A. comprises a further acrylate,

B. is superimposed on the base layer; wherein at least 50 %, preferably at least 60 %, and more preferably at least 70 % of the polymer particles in a cross-sectional cut of the base layer have a diameter in the range of 0.1 mm to 40.0 mm, preferably in the range of 0.5 mm to 35.0 mm, and more preferably in the range of 1.0 mm to 30.0 mm, wherein the diameter of a given polymer particle is the longest cross-sectional length of the given polymer particle.

The invention also pertains to methods for producing the interlockable units, as well as the use of the interlockable units. The invention also pertains to a sports surface and a method for pro ducing a sports surface. BACKGROUND

Sports surfaces, such as clay tennis courts, are commonly available worldwide. As these sports surfaces are mostly outside, the surfaces are subjected to the weather. For example, if the sports surface has an insufficient water infiltration rate, rain water will collect on the sports surface. This makes the sports surface unusable, even after the rain has stopped. Another example of weather-related problems is that sports surfaces tend to crack in winter times due to lower tem peratures, which very often requires costly repairs. Another problem with current sports surfaces are that they are expensive to produce and maintain. This is especially true if the sports surface should have specific characteristics such as shock absorption and energy restitution.

US3,859,768 discloses tennis court units for the production of a tennis court. While this enables an easier construction of a tennis court, the tennis court units cannot be easily disassembled. Furthermore, the tennis court units have an insufficient water infiltration rate, i.e., any water that collects on the surface of the tennis court units will not easily drain away. As the surface of the tennis court units are from plywood, this negatively influences shock absorption and energy restitution

US4,054,987 discloses interlocking sheets for the construction of a ball playing surface. While the interlocking sheets have a higher water infiltration rate, construction of the ball playing sur face requires that the interlocking sheets should be tensioned during construction. This increases the complexity of the construction process. Furthermore, regular use of the ball playing surface will lead to a decrease in the tension, which would require that the interlocking sheets would have to be re-tensioned. This increases maintenance complexity and costs.

CN108556190A discloses a shock-absorbing mat for producing a sports surface covered with artificial turf. The mat comprises a plurality of polyethylene particles with voids between the particles. While the voids can lead to an improved water infiltration rate, this requires that the voids should be relatively large. This negatively influences energy restitution, shock absorption, and the durability of the mat. OBJECTS OF THE INVENTION

An object of the present invention is to at least partially overcome at least one of the disad vantages encountered in the state of the art.

It is a further object of the invention to provide an interlockable unit, preferably an interlockable unit for producing a sports surface.

It is a further object of the invention to provide an interlockable unit, preferably an interlockable unit for producing a sports surface, that has an increased water infiltration rate.

It is a further object of the invention to provide an interlockable unit, preferably an interlockable unit for producing a sports surface, that has an increased shock absorption.

It is a further object of the invention to provide an interlockable unit, preferably an interlockable unit for producing a sports surface, that has an improved energy restitution.

It is a further object of the invention to provide an interlockable unit, preferably an interlockable unit for producing a sports surface, that has an improved robustness towards changes in temper ature.

It is a further object of the invention to provide an interlockable unit, preferably an interlockable unit for producing a sports surface, that can be more easily recycled.

It is a further object of the invention to provide a method for producing an interlockable unit, preferably an interlockable unit for a sports surface.

It is a further object of the invention to provide a method that allows for a faster production sports surface.

It is a further object of the invention to provide a sports surface that has an increased water infiltration rate.

It is a further object of the invention to provide a sports surface that has an increased shock absorption.

It is a further object of the invention to provide a sports surface that has an increased energy restitution.

It is a further object of the invention to provide a sports surface that has an improved robustness towards changes in temperature.

It is a further object of the invention to provide a sports surface that can be easily disassembled and reassembled. It is a further object of the invention to provide a sports surface that can be more easily main tained.

It is a further object of the invention to provide a sports surface that can be more easily recycled. It is a further object of the invention to provide a sports surface that can be produced with re duced CO2 emissions.

DETAILED DESCRIPTION OF THE INVENTION

A contribution to at least partially fulfilling at least one of the above-mentioned objects is made by any of the embodiments of the invention.

A first (1 ^st ) embodiments of the invention is an interlockable unit, wherein the interlockable unit a. is adapted and arranged to engage at least one other interlockable unit in an in terlocking manner; b. comprises the following layers: i. a base layer, wherein the base layer comprises a plurality of polymer par ticles; ii. a further intermediate layer, wherein the further intermediate layer

A. comprises a further acrylate,

B. is superimposed on the base layer; wherein at least 50 %, preferably at least 60 %, and more preferably at least 70 % of the polymer particles in a cross-sectional cut of the base layer have a diameter in the range of 0.1 mm to 40.0 mm, preferably in the range of 0.5 mm to 35.0 mm, and more preferably in the range of 1.0 mm to 30.0 mm, wherein the diameter of a given polymer particle is the longest cross-sectional length of the given polymer particle.

In a preferred embodiment of the interlockable unit, the interlockable unit further comprises a plurality of perforations. This preferred embodiment is a 2 ^nd embodiment of the invention, that preferably depends on the 1 ^st embodiment of the invention. In a preferred embodiment of the interlockable unit, the plurality of polymer particles are porous, preferably a foam, more preferably a foam comprising at least 60 %, even more preferably at least 70 %, and further preferably at least 80 % closed cells. This preferred embodiment is a 3 ^rd embodiment of the invention, that preferably depends on any of the 1 ^st to 2 ^nd embodiments of the invention.

In a preferred embodiment of the interlockable unit, the plurality of polymer particles comprise a thermoplastic polymer, preferably a polyolefin, and more preferably a polymer selected from the group consisting of polyethylene, polypropylene, and a combination thereof. Cross-linked polyethylene is particularly preferred. This preferred embodiment is a 4 ^th embodiment of the invention, that preferably depends on any of the 1 ^st to 3 ^rd embodiments of the invention.

In a preferred embodiment of the interlockable unit, a volume of the plurality of polymer parti cles is in the range of 70 % to 99 %, more preferably in the range of 80 % to 95 %, and further preferably in the range of 85 % to 95 % of a total volume of the base layer. This preferred embodiment is a 5 ^th embodiment of the invention, that preferably depends on any of the 1 ^st to 4 ^th embodiments of the invention.

In a preferred embodiment of the interlockable unit, the base layer has at least one or all of the following properties: a. an ultimate tensile strength in the range of 0.15 MPa to 0.38 MPa, preferably in the range of 0.20 MPa to 0.33 MPa, and more preferably in the range of 0.23 MPa to 0.29 MPa; b. an ultimate tensile strength after aging in the range of 0.14 MPa to 0.37 MPa, preferably in the range of 0.19 MPa to 0.32 MPa, and more preferably in the range of 0.22 MPa to 0.28 MPa; c. a water infiltration rate that is at least 60 000 mm/h, preferably at least 65 000 mm/h, and more preferably at least 70 000 mm/h; d. a mass per unit area in the range of 3.5 kg/m ² to 4.8 kg/m ² , preferably in the range of 3.7 kg/m ² to 4.5 kg/m ² , and more preferably in the range of 3.9 kg/m ² to 4.3 kg/m ² .

This preferred embodiment is a 6 ^th embodiment of the invention, that preferably depends on any of the 1 ^st to 5 ^th embodiments of the invention. For the 6 ^th embodiment, all possible combination of the features a. to d. are preferred aspects of the embodiment. These combinations are e.g., a; b; c; d; a, b; a, c; a, d; b, c; b, d; c, d; a, b, c; a, b, d; a, c, d; b, c, d; a, b, c, d.

In a preferred embodiment of the interlockable unit, the base layer has at least one or all of the following properties: a. a shock absorption in the range of 23 % to 47 %, preferably in the range of 28 % to 42 %, and more preferably in the range of 32 % to 38 %; b. an energy restitution in the range of 48 % to 66 %, preferably in the range of 52 % to 62 %, and more preferably in the range of 55 % to 59 %; c. a vertical deformation in the range of 2.1 mm to 3.5 mm, preferably in the range of 2.4 mm to 3.2 mm, and more preferably in the range of 2.6 mm to 3.0 mm; d. a shock absorption in the range of 22 % to 47 %, preferably in the range of 28 % to 41 %, and more preferably in the range of 31 % to 38 %.

This preferred embodiment is a 7 ^th embodiment of the invention, that preferably depends on any of the 1 ^st to 6 ^th embodiments of the invention. For the 7 ^th embodiment, all possible combination of the features a. to d. are preferred aspects of the embodiment. These combinations are e.g., a; b; c; d; a, b; a, c; a, d; b, c; b, d; c, d; a, b, c; a, b, d; a, c, d; b, c, d; a, b, c, d.

In a preferred embodiment of the interlockable unit, the interlockable unit has a first outermost surface and, opposite the first outermost surface, a further outermost surface, and in the range of 10 % to 100 %, more preferably in the range of 20 % to 95 %, even more preferably in the range of 30 % to 85 %, and further preferably in the range of 40 % to 75 % of the plurality of perfora tions extend from the first outermost surface to the further outer-most surface. This preferred embodiment is an 8 ^th embodiment of the invention, that preferably depends on any of the 2 ^nd to 7 ^th embodiments of the invention. In a preferred embodiment of the interlockable unit, the diameters of at least 40 %, preferably at least 50 %, and more preferably at least 60 % of the plurality of polymer particles, in a cross- sectional cut of the base layer, are arranged along a length of the base layer. This preferred embodiment is a 9 ^th embodiment of the invention, that preferably depends on any of the 1 ^st to 8 ^th embodiments of the invention.

In a preferred embodiment of the interlockable unit, the base layer comprises a plurality of pol ymer fibres. This preferred embodiment is a 10 ^th embodiment of the invention, that preferably depends on any of the 1 ^st to 9 ^th embodiments of the invention.

In a preferred embodiment of the interlockable unit, at least one or all of the following applies: a. the plurality of polymer fibres comprises a thermosetting polymer, a thermo plastic polymer, or a combination thereof. A preferred thermosetting polymer is polyurethane. A preferred a thermoplastic polymer is a polyester, e.g ., polyeth ylene terephthalate; b. the plurality of polymer fibres are arranged on at least one surface of the base layer; c. the plurality of polymer fibres are woven.

This preferred embodiment is an 11 ^th embodiment of the invention, that preferably depends on the 10 ^th embodiment of the invention. For the 11 ^th embodiment, all possible combination of the features a. to c. are preferred aspects of the embodiment. These combinations are e.g., a; b; c; a, b; a, c; b, c; a, b, c.

In a preferred embodiment of the interlockable unit, the further intermediate layer has at least one or all of the following properties: a. a density (at 20°C) in the range of 0.5 g/cm ³ to 2.0 g/cm ³ , preferably in the range of 0.9 g/cm ³ to 1.7 g/cm ³ , and more preferably in the range of 1.1 g/cm ³ to 1.5 g/cm ³ ; b. an elongation at yield in the range of 20 % to 60 %, preferably in the range of 30 % to 50 %, and more preferably in the range of 35 % to 45 %; c. a tensile strength in the range of 4 N/mm ² to 16 N/mm ² , preferably in the range of 7 N/mm ² to 13 N/mm ² , and more preferably in the range of 9 N/mm ² to 11 N/mm ² ; d. a Shore 00 hardness in the range of 1 to 120, preferably in the range of 5 to 100, and more preferably in the range of 15 to 75.

This preferred embodiment is a 12 ^th embodiment of the invention, that preferably depends on any of the 1 ^st to 11 ^th embodiments of the invention. For the 12 ^th embodiment, all possible com bination of the features a. to d. are preferred aspects of the embodiment. These combinations are e.g., a; b; c; d; a, b; a, c; a, d; b, c; b, d; c, d; a, b, c; a, b, d; a, c, d; b, c, d; a, b, c, d.

In a preferred embodiment of the interlockable unit, the interlockable unit further comprises a first intermediate layer, and wherein the first intermediate layer a. comprises a first acrylate; and b. is superimposed on the base layer.

This preferred embodiment is a 13 ^th embodiment of the invention, that preferably depends on any of the 1 ^st to 12 ^th embodiments of the invention. In an aspect of the 13 ^th embodiment, it is preferred that the further intermediate layer is superimposed on the first intermediate layer. E.g., a cross-sectional cut of the interlockable unit comprises the following layers, in this order: the base layer, the first intermediate layer, and the further intermediate layer.

In a preferred embodiment of the interlockable unit, the first intermediate layer further comprises at least one or all of the following: a. elongated material, preferably fibres; b. first parti culated material.

This preferred embodiment is a 14 ^th embodiment of the invention, that preferably depends on the 13 ^th embodiment of the invention. For the 14 ^th embodiment, all possible combination of the features a. and b. are preferred aspects of the embodiment. These combinations are e.g., a; b; a, b.

In a preferred embodiment of the interlockable unit, the first particulated material comprises at least 50 wt.-%, more preferably at least 70 wt.-%, and further preferably at least 95 wt.-% inorganic particulated material, based on the total weight of the first particulated material. It is particularly preferred that the first particulated material comprises at least one or all of the fol lowing: silica, a calcium carbonate, e.g ., aragonite, a calcium sulphate, e.g, gypsum and selenite, and a combination of two or more thereof. This preferred embodiment is a 15 ^th embodiment of the invention, that preferably depends on the 14 ^th embodiment of the invention.

In a preferred embodiment of the interlockable unit, the first intermediate layer has at least one or all of the following properties: a. a density (at 20°C) in the range of 0.5 g/cm ³ to 2.0 g/cm ³ , preferably in the range of 0.9 g/cm ³ to 1.7 g/cm ³ , and more preferably in the range of 1.1 g/cm ³ to 1.5 g/cm ³ ; b. a Shore 00 hardness in the range of 1 to 120, preferably in the range of 5 to 100, and more preferably in the range of 15 to 75.

This preferred embodiment is a 16 ^th embodiment of the invention, that preferably depends on any of the 13 ^th to 15 ^th embodiments of the invention. For the 16 ^th embodiment, all possible com bination of the features a. and b. are preferred aspects of the embodiment. These combinations are e.g., a; b; a, b.

In a preferred embodiment of the interlockable unit, the interlockable unit further comprises a surface layer, wherein the surface layer is superimposed on the further intermediate layer. This preferred embodiment is a 17 ^th embodiment of the invention, that preferably depends on any of the 1 ^st to 16 ^th embodiments of the invention. In an aspect of the 17 ^th embodiment, it is preferred that a cross-sectional cut of the interlockable unit comprises the following layers, in this order: the base layer, the further intermediate layer, and the surface layer. In this aspect, it is more preferred that a cross-sectional cut of the interlockable unit comprises the following layers, in this order: the base layer, the first intermediate layer, the further intermediate layer, and the surface layer.

In a preferred embodiment of the interlockable unit, the surface layer comprises an even-further acrylate. This preferred embodiment is an 18 ^th embodiment of the invention, that preferably de pends on the 17 ^th embodiment of the invention. In a preferred embodiment of the interlockable unit, the surface layer further comprises even- further particulated material. This preferred embodiment is a 19 ^th embodiment of the invention, that preferably depends on any of the 17 ^th to 18 ^th embodiments of the invention.

In a preferred embodiment of the interlockable unit, the even-further particulated material com prises at least 50 wt.-%, more preferably at least 70 wt.-%, and further preferably at least 95 wt.- % inorganic particulated material, based on the total weight of the even-further particulated ma terial. This preferred embodiment is a 20 ^th embodiment of the invention, that preferably depends on the 19 ^th embodiment of the invention.

In a preferred embodiment of the interlockable unit, the even-further particulated material com prises at least one or all of the following: silica, a calcium carbonate, e.g ., aragonite and lime stone, a calcium sulphate, e.g. , gypsum and selenite, coal, a metal oxide, e.g. , silicon dioxide, and a combination of two or more thereof. This preferred embodiment is a 21 ^st embodiment of the invention, that preferably depends on any of the 19 ^th to 20 ^th embodiments of the invention.

In a preferred embodiment of the interlockable unit, the even-further particulated material has a size in the range of 0.01 mm to 30.0 mm, preferably in the range of 0.05 mm to 20.0 mm, more preferably in the range of 0.1 mm to 15.0 mm, further preferably in the range of 0.1 mm to 8.0 mm, and even further preferably in the range of 0.1 mm to 0.5 mm. This preferred embodiment is a 22 ^nd embodiment of the invention, that preferably depends on any of the 19 ^th to 21 ^st embod iments of the invention.

In a preferred embodiment of the interlockable unit, an average length of the plurality of perfo rations varies by less than 25 %, preferably by less than 20 %, more preferably by less than 15 %, further preferably by less than 10 %, and even further preferably by less than 5 % from an average thickness of the interlockable unit. This preferred embodiment is a 23 ^rd embodiment of the invention, that preferably depends on any of the 2 ^nd to 22 ^nd embodiments of the invention. In an aspect of the 23 ^rd embodiment, it is preferred that at least 50 %, preferably at least 75 %, and more preferably at least 95 % of the plurality of perforations are perpendicular to at least one or all of the following: the first outermost surface of the interlockable unit, and the further outermost surface of the interlockable unit.

In a preferred embodiment of the interlockable unit, at least one or all of the following applies to at least 50 %, preferably at least 75 %, and more preferably at least 95 % of the plurality of perforations: a. a cross-sectional area of the perforation, made perpendicular to a length of the perforation, has one of the following shapes: a circle, a square, a triangle, an el lipse, a rectangle, a slit; b. a first dimension in the range of 0.5 mm to 5.0 mm, preferably in the range of 0.8 mm to 3.0 mm, and more preferably in the range of 1.2 mm to 2.0 mm; c. a further dimension in the range of 40 mm to 120 mm, preferably in the range of 60 mm to 100 mm, and more preferably in the range of 75 mm to 85 mm.

This preferred embodiment is a 24 ^th embodiment of the invention, that preferably depends on any of the 2 ^nd to 23 ^rd embodiments of the invention. For the 24 ^th embodiment, all possible com bination of the features a. to c. are preferred aspects of the embodiment. These combinations are e.g ., a; b; c; a, b; a, c; b, c; a, b, c. In an aspect of the 24 ^th embodiment, it is preferred that the cross-sectional area has, to a first approximation, one of the following shapes; a circle, a square, a triangle, an ellipse, a rectangle, a slit. In an aspect of the 24 ^th embodiment, it is preferred to measure the first dimension of the perforation parallel to at least one or all of the following: the first outermost surface, the further outermost surface. In an aspect of the 24 ^th embodiment, it is preferred to measure the further dimension of the perforation parallel to at least one or all of the following: the first outermost surface, the further outermost surface. An example of the first dimension is a diameter of an opening of the perforation, if the opening is in the form of a circle. An example of the further dimension is a length of an opening of the perforation, if the opening of the perforation is in the form of a slit.

In a preferred embodiment of the interlockable unit, the plurality of perforations cover less than 50 %, more preferably less than 40 %, even more preferably less than 30 %, and further prefer ably less than 20 % of a surface area of at least one or all of the following: the first outer most surface of the interlockable unit, the further outermost surface of the interlockable unit. This preferred embodiment is a 25 ^th embodiment of the invention, that preferably depends on any of the 2 ^nd to 24 ^th embodiments of the invention.

In a preferred embodiment of the interlockable unit, at least one or all of the following applies: a. the base layer has a thickness in the range of 3 mm to 40 mm, preferably in the range of 5 mm to 35 mm, more preferably in the range of 10 mm to 20 mm, and further preferably in the range of 13 mm to 17 mm; b. the first intermediate layer has a thickness in the range of 0.2 mm to 3.0 mm, preferably in the range of 0.4 mm to 1.5 mm, and more preferably in the range of 0.6 mm to 0.9 mm; c. the further intermediate layer has a thickness in the range of 0.2 mm to 3.0 mm, preferably in the range of 0.4 mm to 1.5 mm, and more preferably in the range of 0.6 mm to 0.9 mm; d. the surface layer has a thickness in the range of 0.2 mm to 3.0 mm, preferably in the range of 0.4 mm to 1.5 mm, and more preferably in the range of 0.6 mm to 0.9 mm.

This preferred embodiment is a 26 ^th embodiment of the invention, that preferably depends on any of the 1 ^st to 25 ^th embodiments of the invention. For the 26 ^th embodiment, all possible com bination of the features a. to d. are preferred aspects of the embodiment. These combinations are e.g., a; b; c; d; a, b; a, c; a, d; b, c; b, d; c, d; a, b, c; a, b, d; a, c, d; b, c, d; a, b, c, d.

In a preferred embodiment of the interlockable unit, the interlockable unit has at least one or all of the following properties: a. a first dimension in the range of 0.60 m to 1.50 m, preferably in the range of 0.75 m to 1.30 m, and more preferably in the range of 0.85 m to 1.00 m; b. a further dimension, measured perpendicular to the first dimension, in the range of 1.50 m to 3.00 m, preferably in the range of 1.80 m to 2.60 m, and more pref erably in the range of 2.10 m to 2.40 m.

This preferred embodiment is a 27 ^th embodiment of the invention, that preferably depends on any of the 1 ^st to 26 ^th embodiments of the invention. For the 27 ^th embodiment, all possible com bination of the features a. and b. are preferred aspects of the embodiment. These combinations are e.g., a; b; a, b. In an aspect of the 27 ^th embodiment, an example of the first dimension is a width or a length. In an aspect of the 27 ^th embodiment, an example of the further dimension is a width or a length.

In a preferred embodiment of the interlockable unit, the interlockable unit further comprises at least one or all of the following: a. at least one protrusion, preferably at least one protrusion that is adapted and ar ranged to mate with at least one indentation of at least one other interlockable unit; b. at least one indentation, preferably at least one indentation that is adapted and arranged to mate with at least one protrusion of at least one other interlockable unit.

This preferred embodiment is a 28 ^th embodiment of the invention, that preferably depends on any of the 1 ^st to 27 ^th embodiments of the invention. For the 28 ^th embodiment, all possible com bination of the features a. and b. are preferred aspects of the embodiment. These combinations are e.g., a; b; a, b.

In a preferred embodiment of the interlockable unit, at least one or all of the following applies: a. a first dimension of the at least one protrusion is in the range of 10 mm to 100 mm, preferably in the range of 20 mm to 80 mm, and more preferably in the range of 40 mm to 60 mm; b. a further dimension of the at least one protrusion, measured perpendicular to the first dimension of the at least one protrusion, is in the range of 85 mm to 150 mm, preferably in the range of 105 mm to 135 mm, and more preferably in the range of 114 mm to 122 mm; c. a first dimension of the at least one indentation is in the range of 1 mm to 10 mm, preferably in the range of 2 mm to 8 mm, and more preferably in the range of 4 mm to 6 mm; d. a further dimension of the at least one indentation, measured perpendicular to the first dimension of the at least one indentation, is in the range of 85 mm to 150 mm, preferably in the range of 105 mm to 135 mm, and more preferably in the range of 114 mm to 122 mm;

This preferred embodiment is a 29 ^th embodiment of the invention, that preferably depends on any of the 1 ^st to 28 ^th embodiment of the invention. For the 29 ^th embodiment, all possible combi nation of the features a. to d. are preferred aspects of the embodiment. These combinations are e.g., a; b; c; d; a, b; a, c; a, d; b, c; b, d; c, d; a, b, c; a, b, d; a, c, d; b, c, d; a, b, c, d. In an aspect of the 29 ^th embodiment, an example of the first dimension of the at least one protrusion is a width or a length. In an aspect of the 29 ^th embodiment, an example of the further dimension of the at least one protrusion is a width or a length. In an aspect of the 29 ^th embodiment, an example of the first dimension of the at least one indentation is a width or a length. In an aspect of the 29 ^th embodiment, an example of the further dimension of the at least one indentation is a width or a length. In an aspect of the 29 ^th embodiment, it is preferred that the first dimension of the at least one protrusion is measured perpendicular to a side of the interlockable unit from which the protrusion protrudes. In an aspect of the 29 ^th embodiment, it is preferred that the further dimen sion of the at least one protrusion is measured parallel to a side of the interlockable unit from which the protrusion protrudes. In an aspect of the 29 ^th embodiment, it is preferred that the first dimension of the at least one indentation is measured perpendicular to a side of the interlockable unit into which the indentation indents. In an aspect of the 29 ^th embodiment, it is preferred that the further dimension of the at least one indentation is measured parallel to a side of the inter lockable unit into which the indentation indents.

In a preferred embodiment of the interlockable unit, at least one or all of the following applies: a. in the range of 5% to 40 %, preferably in the range of 10% to 35 %, and more preferably in the range of 22 % to 28 % of the first dimension of the interlockable unit comprises either the at least one protrusion, the at least one indentation, or both; b. in the range of 5% to 35 %, preferably in the range of 10% to 30 %, and more preferably in the range of 17 % to 23 % of the further dimension of the interlock able unit comprises either the at least one protrusion, the at least one indentation, or both. This preferred embodiment is a 30 ^th embodiment of the invention, that preferably depends on any of the 27 ^th to 29 ^th embodiments of the invention. For the 30 ^th embodiment, all possible com bination of the features a. and b. are preferred aspects of the embodiment. These combinations are e.g., a; b; a, b.

In a preferred embodiment of the interlockable unit, the interlockable unit does not comprise a rubber. This preferred embodiment is a 31 ^st embodiment of the invention, that preferably de pends on any of the 1 ^st to 30 ^th embodiments of the invention.

In a preferred embodiment of the interlockable unit, the base layer has a density in the range of 0.17 g/cm ³ to 0.46 g/cm ³ , preferably in the range of 0.20 g/cm ³ to 0.43 g/cm ³ , even more pref erably in the range of 0.25 g/cm ³ to 0.38 g/cm ³ , and further preferably in the range of 0.29 g/cm ³ to 0.33 g/cm ³ . This preferred embodiment is a 32 ^nd embodiment of the invention, that preferably depends on any of the 1 ^st to 31 ^st embodiments of the invention.

In a preferred embodiment of the interlockable unit, the surface layer comprises at least one or all of the following: a thermosetting polymer, a thermoplastic polymer, or a combination thereof. A preferred thermosetting polymer is polyurethane. A preferred a thermoplastic polymer is a polyester, e.g. , polyethylene terephthalate. This preferred embodiment is a 33 ^rd embodiment of the invention, that preferably depends on any of the 17 ^th to 32 ^nd embodiments of the invention. In an aspect of the 33 ^rd embodiment, it is preferred that the surface layer comprises more than 50 wt.%, based on the total weight of the surface layer, of a thermosetting polymer, preferably a polyurethane. In an aspect of the 33 ^rd embodiment, it is preferred that the surface layer com prises a rubber, more preferably in the form of rubber granulates.

A thirty-fourth (34 ^th ) embodiment of the invention is a first sports surface comprising a. a foundation, b. a plurality of interlockable units, preferably a plurality of interlockable units ac cording to any of the 1 ^st to 33 ^rd embodiments of the invention, wherein the plurality of interlockable units are interlocked with each other and superim posed on the foundation.

In an aspect of the 34 ^th embodiment, a preferred first sports surface is a tennis court, more pref erably a clay tennis court, a netball court, and a basketball court.

In a preferred embodiment of the first sports surface, a 10 m ² surface area of the first sports surface comprises in the range of 0.5 to 20, more preferably in the range of 1 to 15, even more preferably in the range of 2 to 10, and further preferably in the range of 2 to 5 interlockable units. This preferred embodiment is a 35 ^th embodiment of the invention, that preferably depends on the 34 ^th embodiment of the invention.

In a preferred embodiment of the first sports surface, the foundation comprises other particulated material, and wherein the other particulated material is preferably unbound particulated material. This preferred embodiment is a 36 ^th embodiment of the invention, that preferably depends on any of the 34 ^th to 35 ^th embodiments of the invention.

In a preferred embodiment of the first sports surface, the other particulated material comprises at least 50 wt.-%, more preferably at least 70 wt.-%, and further preferably at least 95 wt.-% inorganic particulated material, based on the total weight of the other particulated material. This preferred embodiment is a 37 ^th embodiment of the invention, that preferably depends on the 36 ^th embodiment of the invention.

In a preferred embodiment of the first sports surface, the other particulated material comprises at least one or all of the following: a. silica, a calcium carbonate, e.g. , aragonite and limestone, a calcium sulphate, e.g. , gypsum and selenite, coal, a metal oxide, e.g. , silicon dioxide, and a combination of two or more thereof; b. construction aggregate, sand, gravel, crushed stone, slag, recycled concrete, crushed brick, shale, clay particles, asphalt, and a combination of two or more thereof.

This preferred embodiment is a 38 ^th embodiment of the invention, that preferably depends on any of the 36 ^th to 37 ^th embodiments of the invention. For the 38 ^th embodiment, all possible combination of the features a. and b. are preferred aspects of the embodiment. These combina tions are e.g., a; b; a, b.

In a preferred embodiment of the first sports surface, the other particulated material has a size in the range of 0.1 mm to 100.0 mm, preferably in the range of 0.5 mm to 80.0 mm, more pref erably in the range of 1.0 mm to 60.0 mm. This preferred embodiment is a 39 ^th embodiment of the invention, that preferably depends on any of the 36 ^th to 38 ^th embodiments of the invention.

In a preferred embodiment of the first sports surface, the interlockable units cover at least 70 %, preferably at least 80 %, and more preferably at least 95 % of a surface of the foundation. This preferred embodiment is a 40 ^th embodiment of the invention, that preferably depends on any of the 34 ^th to 39 ^th embodiments of the invention.

In a preferred embodiment of the first sports surface, the first sports surface does not comprise any of the following: grass, sports turf, synthetic turf, and wood, e.g. , plywood. This preferred embodiment is a 41 ^st embodiment of the invention, that preferably depends on any of the 34 ^th to 40 ^th embodiments of the invention.

A forty-second (42 ^nd ) embodiment of the invention is a first method for producing a plurality of interlockable units, comprising the steps of a. providing a plurality of elements, wherein the plurality of elements are adapted and arranged to engage each other in an interlocking manner; b. arranging the plurality of elements in an interlocking manner; c. coating the plurality of elements with a further intermediate layer; d. increasing the hardness of the further intermediate layer; e. obtaining the plurality of interlockable units; wherein the plurality of interlockable units are obtained by separating the coated and in terlocked plurality of elements.

In an aspect of the 42 ^nd embodiment, it is preferred to separate the coated and interlocked plu rality of elements after the hardness of the intermediate layer has been increased. In a preferred embodiment of the first method for producing a plurality of interlockable units, the plurality of elements each comprise a plurality of perforations. This preferred embodiment is a 43 ^rd embodiment of the invention, that preferably depends on the 42 ^nd embodiment of the invention.

In a preferred embodiment of the first method for producing a plurality of interlockable units, the coated and interlocked plurality of elements are separated using a mechanical force. This preferred embodiment is a 44 ^th embodiment of the invention, that preferably depends on any of the 42 ^nd to 43 ^rd embodiments of the invention. A “mechanical force” should be understood to mean a force that results from the direct contact of at least one element of the plurality of ele ments with another entity, e.g ., a human hand or a tool.

In a preferred embodiment of the first method for producing a plurality of interlockable units, the coated and interlocked plurality of elements are separated without cutting the coated and interlocked plurality of elements. This preferred embodiment is a 45 ^th embodiment of the inven tion, that preferably depends on any of the 42 ^nd to 44 ^th embodiments of the invention. Examples of cutting include using a blade, a water jet cutter, or a laser to separate the coated and inter locked plurality of elements.

In a preferred embodiment of the first method for producing a plurality of interlockable units, the method further comprises the steps of a. coating the plurality of elements with a first intermediate layer; and b. increasing the hardness of the first intermediate layer.

This preferred embodiment is a 46 ^th embodiment of the invention, that preferably depends on any of the 42 ^nd to 45 ^th embodiments of the invention. In one aspect of the 46 ^th embodiment, it is preferred to coat the plurality of elements with the first intermediate layer prior to coating the plurality of elements with the further intermediate layer. In this aspect, it is preferred to coat the plurality of elements with the further intermediate layer after the hardness of the first intermedi ate layer has been increased. In a preferred embodiment of the first method for producing a plurality of interlockable units, the method further comprises the steps of a. coating the plurality of elements with a surface layer; and b. increasing the hardness of the surface layer.

This preferred embodiment is a 47 ^th embodiment of the invention, that preferably depends on any of the 42 ^nd to 46 ^th embodiments of the invention. In one aspect of the 47 ^th embodiment, it is preferred to coat the plurality of elements with the surface layer after coating the plurality of elements with the first intermediate layer. In this aspect, it is preferred to coat the plurality of elements with the surface layer after the hardness of the first intermediate layer has been in creased. In one aspect of the 47 ^th embodiment, it is preferred to coat the plurality of elements with the surface layer after coating the plurality of elements with the further intermediate layer. In this aspect, it is preferred to coat the plurality of elements with the surface layer after the hardness of the further intermediate layer has been increased. In one aspect of the 47 ^th embodi ment, it is preferred to separate the coated and interlocked plurality of elements after coating the plurality of elements with the surface layer. In this aspect, it is preferred to separate the coated and interlocked plurality of elements after the hardness of the surface layer has been increased. In one aspect of the 47 ^th embodiment, it is preferred that the surface layer is in the form of an acrylic emulsion.

A forty-eight (48 ^th ) embodiment of the invention is a further method for producing a plurality of interlockable units, comprising the steps of a. providing a plurality of elements, wherein the plurality of elements are adapted and arranged to engage each other in an interlocking manner; b. coating the plurality of elements with a further intermediate layer; c. increasing the hardness of the further intermediate layer; d. obtaining the plurality of interlockable units; wherein the plurality of elements are coated with the further intermediate layer while the plurality of elements are not arranged in an interlocking manner. In a preferred embodiment of the further method for producing a plurality of interlockable units, the plurality of elements each comprise a plurality of perforations. This preferred embodiment is a 49 ^th embodiment of the invention, that preferably depends on the 48 ^th embodiment of the invention.

In a preferred embodiment of the further method for producing a plurality of interlockable units, the method further comprises the steps of a. coating the plurality of elements with a first intermediate layer; and b. increasing the hardness of the first intermediate layer.

This preferred embodiment is a 50 ^th embodiment of the invention, that preferably depends on any of the 48 ^th to 49 ^th embodiments of the invention. In one aspect of the 50 ^th embodiment, it is preferred to coat the plurality of elements with the first intermediate layer prior to coating the plurality of elements with the further intermediate layer. In this aspect, it is preferred to coat the plurality of elements with the further intermediate layer after the hardness of the first intermedi ate layer has been increased. In another aspect of the 50 ^th embodiment, it is preferred to coat the plurality of elements with the first intermediate layer while the plurality of elements are not arranged in an interlocking manner.

In a preferred embodiment of the further method for producing a plurality of interlockable units, the method further comprises the steps of a. coating the plurality of elements with a surface layer; and b. increasing the hardness of the surface layer.

This preferred embodiment is a 51 ^st embodiment of the invention, that preferably depends on any of the 48 ^th to 50 ^th embodiments of the invention. In one aspect of the 51 ^st embodiment, it is preferred to coat the plurality of elements with the surface layer after coating the plurality of elements with the first intermediate layer. In this aspect, it is preferred to coat the plurality of elements with the surface layer after the hardness of the first intermediate layer has been in creased. In one aspect of the 51 ^st embodiment, it is preferred to coat the plurality of elements with the surface layer after coating the plurality of elements with the further intermediate layer. In this aspect, it is preferred to coat the plurality of elements with the surface layer after the hardness of the further intermediate layer has been increased. In another aspect of the 51 ^st embodiment, it is preferred to coat the plurality of elements with the surface layer while the plurality of elements are not arranged in an interlocking manner. In one aspect of the 51 ^st em bodiment, it is preferred that the surface layer is in the form of an acrylic emulsion.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, at least one element, preferably all elements, of the plurality elements comprises a plurality of polymer particles. This preferred embodiment is a 52 ^nd embodiment of the invention, that pref erably depends on any of the 42 ^nd to 47 ^th , and 48 ^th to 51 ^st embodiments of the invention.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, at least 50 %, preferably at least 60 %, and more preferably at least 70 % of the polymer particles in a cross-sectional cut of at least one element, preferably all elements, of the plurality of ele ments have a diameter in the range of 0.1 mm to 40.0 mm, preferably in the range of 0.5 mm to 35.0 mm, and more preferably in the range of 1.0 mm to 30.0 mm, wherein the diameter of a given polymer particle is the longest cross-sectional length of the given polymer particle. This preferred embodiment is a 53 ^rd embodiment of the invention, that preferably depends on the 52 ^nd embodiment of the invention.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, the plurality of polymer particles are porous, preferably a foam, more preferably a foam com prising at least 60 %, even more preferably at least 70 %, and further preferably at least 80 % closed cells. This preferred embodiment is a 54 ^th embodiment of the invention, that preferably depends on any of the 52 ^nd to 53 ^rd embodiments of the invention.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, the plurality of polymer particles comprise a thermoplastic polymer, preferably a polyolefin, and more preferably a polymer selected from the group consisting of polyethylene, polypropylene, and a combination thereof. Cross-linked polyethylene is particularly preferred. This preferred embodiment is a 55 ^th embodiment of the invention, that preferably depends on any of the 52 ^nd to 54 ^th embodiments of the invention. In a preferred embodiment of any of the methods for producing a plurality of interlockable units, a volume of the plurality of polymer particles comprised in at least one element, preferably all elements, in the plurality of elements is in the range of 70 % to 99 %, more preferably in the range of 80 % to 95 %, and further preferably in the range of 85 % to 95 % of a total volume of the at least one element. This preferred embodiment is a 56 ^th embodiment of the invention, that preferably depends on any of the 52 ^nd to 55 ^th embodiments of the invention.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, the diameters of at least 40 %, preferably at least 50 %, and more preferably at least 60 % of the plurality of polymer particles, in a cross-sectional cut of at least one element, preferably all ele ments, of the plurality of elements, are arranged along a length of the at least one element. This preferred embodiment is a 57 ^th embodiment of the invention, that preferably depends on any of the 52 ^nd to 56 ^th embodiments of the invention.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, at least one element, preferably all elements, of the plurality of elements has at least one or all of the following properties: a. an ultimate tensile strength in the range of 0.15 MPa to 0.38 MPa, preferably in the range of 0.20 MPa to 0.33 MPa, and more preferably in the range of 0.23 MPa to 0.29 MPa; b. an ultimate tensile strength after aging in the range of 0.14 MPa to 0.37 MPa, preferably in the range of 0.19 MPa to 0.32 MPa, and more preferably in the range of 0.22 MPa to 0.28 MPa; c. a water infiltration rate that is at least 60 000 mm/h, preferably at least 65 000 mm/h, and more preferably at least 70 000 mm/h; d. a mass per unit area in the range of 3.5 kg/m ² to 4.8 kg/m ² , preferably in the range of 3.7 kg/m ² to 4.5 kg/m ² , and more preferably in the range of 3.9 kg/m ² to 4.3 kg/m ² ;

This preferred embodiment is a 58 ^th embodiment of the invention, that preferably depends on any of the 42 ^nd to 47 ^th , 48 ^th to 51 ^st , and 52 ^nd to 57 ^th embodiments of the invention. For the 58 ^th embodiment, all possible combination of the features a. to d. are preferred aspects of the embodiment. These combinations are e.g., a; b; c; d; a, b; a, c; a, d; b, c; b, d; c, d; a, b, c; a, b, d; a, c, d; b, c, d; a, b, c, d. In an aspect of the 58 ^th embodiment it is preferred that the properties listed above are the properties prior to coating the at least one element with any layer.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, at least one element, preferably all elements, of the plurality of elements has at least one or all of the following properties: a. a shock absorption in the range of 23 % to 47 %, preferably in the range of 28 % to 42 %, and more preferably in the range of 32 % to 38 %; b. an energy restitution in the range of 48 % to 66 %, preferably in the range of 52 % to 62 %, and more preferably in the range of 55 % to 59 %; c. a vertical deformation in the range of 2.1 mm to 3.5 mm, preferably in the range of 2.4 mm to 3.2 mm, and more preferably in the range of 2.6 mm to 3.0 mm; d. a shock absorption in the range of 22 % to 47 %, preferably in the range of 28 % to 41 %, and more preferably in the range of 31 % to 38 %.

This preferred embodiment is a 59 ^th embodiment of the invention, that preferably depends on any of the 42 ^nd to 47 ^th , 48 ^th to 51 ^st , and 52 ^nd to 58 ^th embodiments of the invention. For the 59 ^th embodiment, all possible combination of the features a. to d. are preferred aspects of the embod iment. These combinations are e.g., a; b; c; d; a, b; a, c; a, d; b, c; b, d; c, d; a, b, c; a, b, d; a, c, d; b, c, d; a, b, c, d. In an aspect of the 59 ^th embodiment, it is preferred that the properties listed above are the properties prior to coating the at least one element with any layer.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, each of the plurality of elements have a first outermost surface and, opposite the first outermost surface, a further outermost surface, and in the range of 10 % to 100 %, preferably in the range of 40 % to 95 %, and more preferably in the range of 70 % to 85 % of the plurality of perforations for at least one element, preferably all elements, of the plurality of elements, extend from the first outermost surface to the further outermost surface. This preferred embodiment is a 60 ^th embodiment of the invention, that preferably depends on any of the 43 ^rd to 47 ^th , 49 ^th to 51 ^st , and 52 ^nd to 59 ^th embodiments of the invention. In a preferred embodiment of any of the methods for producing a plurality of interlockable units, at least one element, preferably all elements, of the plurality of elements comprises a plurality of polymer fibres. This preferred embodiment is a 61 ^st embodiment of the invention, that pref erably depends on any of the 42 ^nd to 47 ^th , 48 ^th to 51 ^st , and 52 ^nd to 60 ^th embodiments of the in vention.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, at least one or all of the following applies: a. the plurality of polymer fibres comprises a thermosetting polymer, more prefer ably polyurethane; b. the plurality of polymer fibres are arranged on at least one surface of the base layer; c. the plurality of polymer fibres are woven.

This preferred embodiment is a 62 ^nd embodiment of the invention, that preferably depends on the 61 ^st embodiment of the invention. For the 62 ^nd embodiment, all possible combination of the features a. to c. are preferred aspects of the embodiment. These combinations are e.g ., a; b; c; a, b; a, c; b, c; a, b, c.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, the further intermediate layer has at least one or all of the following properties: a. a density (at 20°C) in the range of 0.5 g/cm ³ to 2.0 g/cm ³ , preferably in the range of 0.9 g/cm ³ to 1.7 g/cm ³ , and more preferably in the range of 1.1 g/cm ³ to 1.5 g/cm ³ ; b. a viscosity, at 20 °C, in the range of 4500 mPa-s to 7500 mPa-s, preferably in the range of 5000 mPa-s to 7000 mPa-s, and more preferably in the range of 5800 mPa-s to 6200 mPa-s.

This preferred embodiment is a 63 ^rd embodiment of the invention, that preferably depends on any of the 42 ^nd to 47 ^th , 48 ^th to 51 ^st , and 52 ^nd to 62 ^nd embodiments of the invention. For the 63 ^rd embodiment, all possible combination of the features a. and b. are preferred aspects of the em bodiment. These combinations are e.g., a; b; a, b. In an aspect of the 63 ^rd embodiment, it is preferred that the above properties are prior to increasing the hardness of the further intermediate layer.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, at least one or all of the following applies: a. the first intermediate layer comprises a first acrylate; b. the further intermediate layer comprises a further acrylate; c. the surface layer comprises an even-further acrylate.

This preferred embodiment is a 64 ^th embodiment of the invention, that preferably depends on any of the 42 ^nd to 47 ^th , 48 ^th to 51 ^st , and 52 ^nd to 63 ^rd embodiments of the invention. For the 64 ^th embodiment, all possible combination of the features a. to c. are preferred aspects of the embod iment. These combinations are e.g ., a; b; c; a, b; a, c; b, c; a, b, c.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, the first intermediate layer further comprises at least one or all of the following: a. elongated material, preferably fibres; b. first parti culated material.

This preferred embodiment is a 65 ^th embodiment of the invention, that preferably depends on any of the 46 ^th to 47 ^th , 50 ^th to 51 ^st , and 52 ^nd to 64 ^th embodiments of the invention. For the 65 ^th embodiment, all possible combination of the features a. and b. are preferred aspects of the em bodiment. These combinations are e.g., a; b; a, b.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, the first particulated material comprises at least 50 wt.-%, more preferably at least 70 wt.-%, and further preferably at least 95 wt.-% inorganic particulated material, based on the total weight of the first particulated material. It is particularly preferred that the first particulated material com prises at least one or all of the following: silica, a calcium carbonate, e.g, aragonite, a calcium sulphate, e.g, gypsum and selenite, and a combination of two or more thereof. This preferred embodiment is a 66 ^th embodiment of the invention, that preferably depends on the 65 ^th embodi ments of the invention. In a preferred embodiment of any of the methods for producing a plurality of interlockable units, the first intermediate layer has at least one or all of the following properties: a. a density (at 20°C) in the range of 0.5 g/cm ³ to 2.0 g/cm ³ , preferably in the range of 0.9 g/cm ³ to 1.7 g/cm ³ , and more preferably in the range of 1.1 g/cm ³ to 1.5 g/cm ³ ; b. a viscosity in the range of 0.5 mPa-s to 200 mPa-s, preferably in the range of 1 mPa-s to 100 mPa-s, and more preferably in the range of 20 mPa-s to 80 mPa-s.

This preferred embodiment is a 67 ^th embodiment of the invention, that preferably depends on any of the 46 ^th to 47 ^th , 50 ^th to 51 ^st , and 52 ^nd to 66 ^th embodiments of the invention. For the 67 ^th embodiment, all possible combination of the features a. and b. are preferred aspects of the em bodiment. These combinations are e.g., a; b; a, b.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, the surface layer further comprises even-further particulated material. This preferred embodi ment is a 68 ^th embodiment of the invention, that preferably depends on any of the 47 ^th , 51 ^st , and 52 ^nd to 67 ^th embodiments of the invention.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, the even-further particulated material comprises at least 50 wt.-%, more preferably at least 70 wt.-%, and further preferably at least 95 wt.-% inorganic particulated material, based on the total weight of the even-further particulated material. This preferred embodiment is a 69 ^th embodi ment of the invention, that preferably depends on the 68 ^th embodiment of the invention.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, the even-further particulated material comprises at least one or all of the following: silica, a calcium carbonate, e.g. , aragonite and limestone, a calcium sulphate, e.g. , gypsum and selenite, coal, a metal oxide, e.g. , silicon dioxide, and a combination of two or more thereof. This pre ferred embodiment is a 70 ^th embodiment of the invention, that preferably depends on any of the 68 ^th to 69 ^th embodiments of the invention. In a preferred embodiment of any of the methods for producing a plurality of interlockable units, the even-further particulated material has a size in the range of 0.01 mm to 30.0 mm, preferably in the range of 0.05 mm to 20.0 mm, more preferably in the range of 0.1 mm to 15.0 mm, further preferably in the range of 0.1 mm to 8.0 mm, and even further preferably in the range of 0.1 mm to 0.5 mm. This preferred embodiment is a 71 ^st embodiment of the invention, that preferably depends on any of the 68 ^th to 70 ^th embodiments of the invention.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, an average length of the plurality of perforations of at least one element, preferably all elements, of the plurality of elements varies by less than 25 %, preferably by less than 20 %, more prefer ably by less than 15 %, further preferably by less than 10 %, and even further preferably by less than 5 % from an average thickness of the plurality of elements. This preferred embodiment is a 72 ^nd embodiment of the invention, that preferably depends on any of the 43 ^rd to 47 ^th , 49 ^th to 51 ^st , and 52 ^nd to 71 ^st embodiments of the invention. In an aspect of the 72 ^nd embodiment, it is preferred that at least 50 %, preferably at least 75 %, and more preferably at least 95 % of the plurality of perforations are perpendicular to the at least one element.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, at least one or all of the following applies to at least 50 %, preferably at least 75 %, and more preferably at least 95 % of the plurality of perforations of at least one element, preferably all elements, of the plurality of elements: a. a cross-sectional area of the perforation, made perpendicular to a length of the perforation, has one of the following shapes: a circle, a square, a triangle, an el lipse, a rectangle, a slit; b. a first dimension in the range of 0.5 mm to 5.0 mm, preferably in the range of 0.8 mm to 3.0 mm, and more preferably in the range of 1.2 mm to 2.0 mm; c. a further dimension in the range of 40 mm to 120 mm, preferably in the range of 60 mm to 100 mm, and more preferably in the range of 75 mm to 85 mm.

This preferred embodiment is a 73 ^rd embodiment of the invention, that preferably depends on any of the 43 ^rd to 47 ^th , 49 ^th to 51 ^st , and 52 ^nd to 72 ^nd embodiments of the invention. For the 73 ^rd embodiment, all possible combination of the features a. to c. are preferred aspects of the embodiment. These combinations are e.g., a; b; c; a, b; a, c; b, c; a, b, c. In an aspect of the 73 ^rd embodiment, it is preferred that the cross-sectional area has, to a first approximation, one of the following shapes; a circle, a square, a triangle, an ellipse, a rectangle, a slit. In an aspect of the 73 ^rd embodiment, it is preferred to measure the first dimension of the perforation parallel to at least one or all of the following: the first outermost surface, the further outermost surface. In an aspect of the 73 ^rd embodiment, it is preferred to measure the further dimension of the perforation parallel to at least one or all of the following: the first outermost surface, the further outermost surface. An example of the first dimension is a diameter of an opening of the perforation, if the opening is in the form of a circle. An example of the further dimension is a length of an opening of the perforation, if the opening of the perforation is in the form of a slit.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, the plurality of perforations cover less than 50 %, more preferably less than 40 %, even more preferably less than 30 %, and further preferably less than 20 % of a surface area of at least one or all of the following: the first outer most surface of at least one element, preferably all elements, of the plurality of elements, the further outermost surface of at least one element, preferably all elements, of the plurality of elements. This preferred embodiment is a 74 ^th embodiment of the invention, that preferably depends on any of the 43 ^rd to 47 ^th , 49 ^th to 51 ^st , and 52 ^nd to 73 ^rd embod iments of the invention.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, at least one element, preferably all elements, of the plurality of elements has at least one or all of the following properties: a. a first dimension in the range of 0.60 m to 1.50 m, preferably in the range of 0.75 m to 1.30 m, and more preferably in the range of 0.85 m to 1.00 m; b. a further dimension, measured perpendicular to the first dimension, in the range of 1.50 m to 3.00 m, preferably in the range of 1.80 m to 2.60 m, and more pref erably in the range of 2.10 m to 2.40 m.

This preferred embodiment is a 75 ^th embodiment of the invention, that preferably depends on any of the 42 ^nd to 47 ^th , 48 ^th to 51 ^st , and 52 ^nd to 74 ^th embodiments of the invention. For the 75 ^th embodiment, all possible combination of the features a. and b. are preferred aspects of the embodiment. These combinations are e.g., a; b; a, b. In an aspect of the 75 ^th embodiment, an example of the first dimension is a width or a length. In an aspect of the 75 ^th embodiment, an example of the further dimension is a width or a length.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, at least one element, preferably all elements, of the plurality of elements further comprises at least one or all of the following: a. at least one protrusion, preferably at least one protrusion that is adapted and ar ranged to mate with at least one indentation of at least one other element of the plurality of elements; b. at least one indentation, preferably at least one indentation that is adapted and arranged to mate with at least one protrusion of at least one other element of the plurality of elements.

This preferred embodiment is a 76 ^th embodiment of the invention, that preferably depends on any of the 42 ^nd to 47 ^th , 48 ^th to 51 ^st , and 52 ^nd to 75 ^th embodiments of the invention. For the 76 ^th embodiment, all possible combination of the features a. and b. are preferred aspects of the em bodiment. These combinations are e.g., a; b; a, b.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, at least one or all of the following applies: a. a first dimension of the at least one protrusion is in the range of 1 mm to 10 mm, preferably in the range of 2 mm to 8 mm, and more preferably in the range of 4 mm to 6 mm; b. a further dimension of the at least one protrusion, measured perpendicular to the first dimension of the at least one protrusion, is in the range of 85 mm to 150 mm, preferably in the range of 105 mm to 135 mm, and more preferably in the range of 114 mm to 122 mm; c. a first dimension of the at least one indentation is in the range of 1 mm to 10 mm, preferably in the range of 2 mm to 8 mm, and more preferably in the range of 4 mm to 6 mm; d. a further dimension of the at least one indentation, measured perpendicular to the first dimension of the at least one indentation, is in the range of 85 mm to 150 mm, preferably in the range of 105 mm to 135 mm, and more preferably in the range of 114 mm to 122 mm;

This preferred embodiment is a 77 ^th embodiment of the invention, that preferably depends on the 76 ^th embodiment of the invention. For the 77 ^th embodiment, all possible combination of the features a. to d. are preferred aspects of the embodiment. These combinations are e.g., a; b; c; d; a, b; a, c; a, d; b, c; b, d; c, d; a, b, c; a, b, d; a, c, d; b, c, d; a, b, c, d. In an aspect of the 77 ^th embodiment, an example of the first dimension of the at least one protrusion is a width or a length. In an aspect of the 77 ^th embodiment, an example of the further dimension of the at least one protrusion is a width or a length. In an aspect of the 77 ^th embodiment, an example of the first dimension of the at least one indentation is a width or a length. In an aspect of the 77 ^th embodiment, an example of the further dimension of the at least one indentation is a width or a length. In an aspect of the 77 ^th embodiment, it is preferred that the first dimension of the at least one protrusion is measured perpendicular to a side of the at least one element from which the protrusion protrudes. In an aspect of the 77 ^th embodiment, it is preferred that the further dimen sion of the at least one protrusion is measured parallel to a side of the at least one element from which the protrusion protrudes. In an aspect of the 77 ^th embodiment, it is preferred that the first dimension of the at least one indentation is measured perpendicular to a side of the at least one element into which the indentation indents. In an aspect of the 77 ^th embodiment, it is preferred that the further dimension of the at least one indentation is measured parallel to a side of the at least one element into which the indentation indents.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, at least one or all of the following applies to at least one element, preferably all elements, of the plurality of elements: a. in the range of 5% to 40 %, preferably in the range of 10% to 35 %, and more preferably in the range of 22 % to 28 % of the first dimension of the at least one element comprises either the at least one protrusion, the at least one indentation, or both; b. in the range of 5% to 35 %, preferably in the range of 10% to 30 %, and more preferably in the range of 17 % to 23 % of the further dimension of the at least one element comprises either the at least one protrusion, the at least one indenta tion, or both.

This preferred embodiment is a 78 ^th embodiment of the invention, that preferably depends on any of the 76 ^th to 77 ^th embodiments of the invention. For the 78 ^th embodiment, all possible com bination of the features a. and b. are preferred aspects of the embodiment. These combinations are e.g., a; b; a, b.

In a preferred embodiment of any of the methods for producing a plurality of interlockable units, at least one element, preferably all elements, of the plurality of elements does not comprise a rubber. This preferred embodiment is a 79 ^th embodiment of the invention, that preferably de pends on any of the 42 ^nd to 47 ^th , 48 ^th to 51 ^st , and 52 ^nd to 78 ^th embodiments of the invention.

An eightieth (80 ^th ) embodiment of the invention is a method for producing a first sports surface, comprising the steps of a. providing i. a foundation, ii. a plurality of interlockable units, wherein the interlockable units

A. are according to the invention, preferably according to any of the 1 ^st to 33 ^rd embodiments, or

B. are obtainable according to any of the methods for producing a plurality of interlockable units, preferably according to any of 42 ^nd to 47 ^th , 48 ^th to 51 ^st , and 52 ^nd to 79 ^th embodiments of the invention, or

C. both A. and B. b. arranging the interlockable units on the foundation in an interlocking manner.

In an aspect of the 80 ^th embodiment, a preferred first sports surface is a tennis court, more pref erably a clay tennis court, a netball court, and a basketball court. In a preferred embodiment of the method for producing a first sports surface, the interlockable units are arranged such that a 10 m ² surface area of the foundation is superimposed with, in the range of 0.5 to 20, more preferably in the range of 1 to 15, even more preferably in the range of 2 to 10, and further preferably in the range of 2 to 5 interlockable units. This preferred embodi ment is an 81 ^st embodiment of the invention, that preferably depends on the 80 ^th embodiment of the invention.

In a preferred embodiment of the method for producing a first sports surface, the foundation comprises other particulated material, and wherein the other particulated material is preferably unbound particulated material. This preferred embodiment is an 82 ^nd embodiment of the inven tion, that preferably depends on any of the 80 ^th to 81 ^st embodiments of the invention.

In a preferred embodiment of the method for producing a first sports surface, the other particu lated material comprises at least 50 wt.-%, more preferably at least 70 wt.-%, and further pref erably at least 95 wt.-% inorganic particulated material, based on the total weight of the other particulated material. This preferred embodiment is an 83 ^rd embodiment of the invention, that preferably depends on the 82 ^nd embodiment of the invention.

In a preferred embodiment of the method for producing a first sports surface, the other particu lated material comprises at least one or all of the following: a. silica, a calcium carbonate, e.g. , aragonite and limestone, a calcium sulphate, e.g. , gypsum and selenite, coal, a metal oxide, e.g. , silicon dioxide, and a combination of two or more thereof; b. construction aggregate, sand, gravel, crushed stone, slag, recycled concrete, crushed brick, shale, clay particles, asphalt, and a combination of two or more thereof.

This preferred embodiment is an 84 ^th embodiment of the invention, that preferably depends on any of the 82 ^nd to 83 ^rd embodiments of the invention. For the 84 ^th embodiment, all possible combination of the features a. and b. are preferred aspects of the embodiment. These combina tions are e.g., a; b; a, b. In a preferred embodiment of the method for producing a first sports surface, the other particu- lated material has a size in the range of 0.1 mm to 100.0 mm, preferably in the range of 0.5 mm to 80.0 mm, more preferably in the range of 1.0 mm to 60.0 mm. This preferred embodiment is an 85 ^th embodiment of the invention, that preferably depends on any of the 82 ^nd to 84 ^th embodi ments of the invention.

In a preferred embodiment of the method for producing a first sports surface, the interlockable units are arranged to cover at least 70 %, preferably at least 80 %, and more preferably at least 95 % of a surface of the foundation. This preferred embodiment is an 86 ^th embodiment of the invention, that preferably depends on any of the 80 ^th to 85 ^th embodiments of the invention.

In a preferred embodiment of the method for producing a first sports surface, the arranged inter lockable units are not covered with a layer comprising any of the following: grass, sports turf, synthetic turf, and wood, e.g ., plywood. This preferred embodiment is an 87 ^th embodiment of the invention, that preferably depends on any of the 80 ^th to 86 ^th embodiments of the invention.

In a preferred embodiment of the method for producing a first sports surface, the method does not comprise the step of applying a tension when arranging the interlockable units on the foun dation. This preferred embodiment is an 88 ^th embodiment of the invention, that preferably de pends on any of the 80 ^th to 87 ^th embodiments of the invention.

An eighty-ninth (89 ^th ) embodiment of the invention is a first sports surface obtainable by a method, according to the invention, for producing a first sports surface, preferably a method according to any of the 80 ^th to 88 ^th embodiments of the invention.

A ninetieth (90 ^th ) embodiment of the invention is a use of a first sports surface according to the invention, preferably a first sports surface according to any of the 34 ^th to 41 ^st , 80 ^th to 88 ^th , and 89 ^th embodiments, as a tennis court, preferably a clay tennis court.

A ninety -first (91 ^st ) embodiment of the invention is a use of a plurality of interlockable units, according to the invention, for producing a first sports surface, preferably at least one or all of the following: a tennis court, more preferably a clay tennis court, a netball court, a basketball court. In an aspect of the 91 ^st embodiment, it is preferred that the plurality of interlockable units are according to any of the 1 ^st to 33 ^rd embodiments of the invention, or obtainable according to any of the 42 ^nd to 47 ^th , 48 ^th to 51 ^st , and 52 ^nd to 79 ^th embodiments of the invention, or both.

A ninety-second (92 ^nd ) embodiment of the invention is a further sports surface comprising a. a foundation, b. a plurality of interlockable elements, wherein the interlockable elements i. are interlocked with each other to form a base layer, ii. are superimposed on the foundation, iii. comprise a plurality of polymer particles; wherein at least 50 %, preferably at least 60 %, and more preferably at least 70 % of the polymer particles in a cross-sectional cut of the base layer have a diameter in the range of 0.1 mm to 40.0 mm, preferably in the range of 0.5 mm to 35.0 mm, and more preferably in the range of 1.0 mm to 30.0 mm, wherein the diameter of a given polymer particle is the longest cross-sectional length of the given polymer particle.

In an aspect of the 92 ^nd embodiment, a preferred further sports surface is a netball court, a hockey field, preferably an indoor hockey field, a cricket pitch, and a basketball court. In an aspect of the 92 ^nd embodiment, it is preferred that at least one or all of the 3 ^rd to 11 ^th , and 32 ^nd embodiments apply to the plurality of polymer particles, the base layer, or both, of the further sports surface. In this aspect, it is preferred that at least one or all of the 3 ^rd to 11 ^th , and 32 ^nd embodiments’ preferred aspects apply to the plurality of polymer particles, the base layer, or both, of the further sports surface. All possible combinations of the 3 ^rd to 11 ^th , and 32 ^nd embodiments, and their preferred aspects, are explicitly disclosed, and preferred when applied to the 92 ^nd embodiment.

In a preferred embodiment of the further sports surface, the further sports surface comprises a further intermediate layer that is superimposed on the base layer, and wherein the further inter mediate layer comprises a further acrylate. This embodiment is a 93 ^rd embodiment of the inven tion, that preferably depends on the 92 ^nd embodiment of the invention. In an aspect of the 93 ^rd embodiment, it is preferred that the 12 ^th embodiment applies to the further intermediate layer of the further sports surface. In this aspect, it is preferred that at least one or all of the 12 ^th embod iment’s preferred aspects apply to the further intermediate layer of the further sports surface. All possible combinations of the 12 ^th embodiment’s preferred aspects are explicitly disclosed, and preferred when applied to the 93 ^rd embodiment.

In a preferred embodiment of the further sports surface, the further sports surface comprises a first intermediate layer that is superimposed on the base layer. This embodiment is a 94 ^th em bodiment of the invention, that preferably depends on any of the 92 ^nd to 93 ^rd embodiments of the invention. In an aspect of the 94 ^th embodiment, it is preferred that the first intermediate layer comprises a first acrylate. In an aspect of the 94 ^th embodiment, it is preferred that at least one or all of the 13 ^th to 16 ^th embodiments apply to the first intermediate layer of the further sports surface. In this aspect, it is preferred that at least one or all of the 13 ^th to 16 ^th embodiments’ preferred aspects apply to the first intermediate layer of the further sports surface. All possible combinations of the 13 ^th to 16 ^th embodiments, and their preferred aspects, are explicitly dis closed, and preferred when applied to the 94 ^th embodiment.

In a preferred embodiment of the further sports surface, the further sports surface comprises a surface layer that is superimposed on the base layer. This embodiment is a 95 ^th embodiment of the invention, that preferably depends on any of the 92 ^nd to 94 ^th embodiments of the invention. In an aspect of the 95 ^th embodiment, it is preferred that the surface layer is superimposed on a further intermediate layer. In an aspect of the 95 ^th embodiment, it is preferred that at least one or all of the 17 ^th to 22 ^nd , and 33 ^rd embodiments apply to the surface layer of the further sports surface. In this aspect, it is preferred that at least one or all of the 17 ^th to 22 ^nd , and 33 ^rd embodi ments’ preferred aspects apply to the surface layer of the further sports surface. All possible combinations of the 17 ^th to 22 ^nd , and 33 ^rd embodiments, and their preferred aspects, are explicitly disclosed, and preferred when applied to the 95 ^th embodiment.

In preferred embodiment of the further sports surface, at least 75 %, more preferably at least 90 % of the elements of the further sports surface comprises a plurality of perforations. This em bodiment is a 96 ^th embodiment of the invention, that preferably depends on any of the 92 ^nd to 95 ^th embodiments of the invention. In an aspect of the 96 ^th embodiment, it is preferred that at least one or all of the 23 ^rd to 25 ^th embodiments apply to the plurality of perforations of the further sports surface. In this aspect, it is preferred that at least one or all of the 23 ^rd to 25 ^th embodiments’ preferred aspects apply to the plurality of perforations of the further sports surface. All possible combinations of the 23 ^rd to 25 ^th embodiments, and their preferred aspects, are explicitly dis closed, and preferred when applied to the 96 ^th embodiment.

In preferred embodiment of the further sports surface, the 26 ^th embodiment applies to at least one or all of the following layers of the further sports surface: the base layer, the first interme diate layer, the further intermediate layer, and the surface layer. This embodiment is a 97 ^th em bodiment of the invention, that preferably depends on any of the 92 ^nd to 96 ^th embodiments of the invention. In an aspect of the 97 ^th embodiment, it is preferred that at least one or all of the pre ferred aspects of the 26 ^th embodiment applies to at least one or all of the following layers of the further sports surface: the base layer, the first intermediate layer, the further intermediate layer, and the surface layer. All possible combinations of the 26 ^th embodiment’s preferred aspects are explicitly disclosed, and preferred, when applied to the 97 ^th embodiment.

In preferred embodiment of the further sports surface, at least one or all of the 27 ^th to 31 ^st em bodiments apply to at least 75 %, more preferably at least 90 % of the elements of the further sports surface. This embodiment is a 98 ^th embodiment of the invention, that preferably depends on any of the 92 ^nd to 97 ^th embodiments of the invention. In an aspect of the 98 ^th embodiment, it is preferred that at least one or all of the 27 ^th to 31 ^st embodiments’ preferred aspects apply to at least 75 %, more preferably at least 90 % of the elements of the further sports surface. All pos sible combinations of the 27 ^th to 31 ^st embodiments, and their preferred aspects, are explicitly disclosed, and preferred when applied to the 98 ^th embodiment.

In a preferred embodiment of the further sports surface, a 10 m ² surface area of the further sports surface comprises in the range of 0.5 to 20, more preferably in the range of 1 to 15, even more preferably in the range of 2 to 10, and further preferably in the range of 2 to 5 interlockable elements. This preferred embodiment is a 99 ^th embodiment of the invention, that preferably de pends on any of the 92 ^nd to 98 ^th embodiments of the invention. In a preferred embodiment of the further sports surface, at least one or all of the 36 ^th to 39 ^th embodiments apply to the foundation of the further sports surface. This preferred embodiment is a 100 ^th embodiment of the invention, that preferably depends on any of the 92 ^nd to 99 ^th em bodiments of the invention. In an aspect of the 100 ^th embodiment, it is preferred that at least one or all of the 36 ^th to 39 ^th embodiments’ preferred aspects apply to the foundation of the further sports surface. All possible combinations of the 36 ^th to 39 ^th embodiments, and their preferred aspects, are explicitly disclosed, and preferred when applied to the 100 ^th embodiment.

In a preferred embodiment of the further sports surface, the plurality of elements cover at least 70 %, preferably at least 80 %, and more preferably at least 95 % of a surface of the foundation. This preferred embodiment is a 101 ^st embodiment of the invention, that preferably depends on any of the 92 ^nd to 100 ^th embodiments of the invention.

In a preferred embodiment of the further sports surface, the further sports surface does not com prise any of the following: grass, sports turf, synthetic turf, and wood, e.g ., plywood. This pre ferred embodiment is a 102 ^nd embodiment of the invention, that preferably depends on any of the 92 ^nd to 101 ^st embodiments of the invention.

In a preferred embodiment of the further sports surface, the further sports surface comprises a fastening means adapted and arranged to fasten the plurality of elements to the foundation. This preferred embodiment is a 103 ^rd embodiment of the invention, that preferably depends on any of the 92 ^nd to 102 ^nd embodiments of the invention. Examples of the fastening means include an adhesive, or a peg, preferably a metal peg, and a metal rod. If an adhesive is used, it is preferred that the adhesive is located between the base layer and the foundation.

A one-hundred-and-fourth (104 ^th ) embodiment of the invention is a method for producing a fur ther sports surface, comprising the steps of a. providing i. a foundation, ii. a plurality of interlockable elements, wherein the interlockable units com prise a plurality of polymer particles, and wherein at least 50 %, preferably at least 60 %, and more preferably at least 70 % of the polymer particles in a cross-sectional cut of at least one of the elements have a diameter in the range of 0.1 mm to 40.0 mm, preferably in the range of 0.5 mm to 35.0 mm, and more preferably in the range of 1.0 mm to 30.0 mm, wherein the diameter of a given polymer particle is the longest cross- sectional length of the given polymer particle; b. arranging the interlockable elements on the foundation in an interlocking manner, thereby forming a base layer that is superimposed on the foundation.

In an aspect of the 104 ^th embodiment, a preferred further sports surface is a netball court, a hockey field, preferably an indoor hockey field, a cricket pitch, and a basketball court. In an aspect of the 104 ^th embodiment, it is preferred that at least 50 %, preferably at least 60 %, and more preferably at least 70 % of the polymer particles in cross-sectional cuts of at least 75 % of the elements have a diameter in the range of 0.1 mm to 40.0 mm, preferably in the range of 0.5 mm to 35.0 mm, and more preferably in the range of 1.0 mm to 30.0 mm. In an aspect of the 104 ^th embodiment, it is preferred that at least 50 %, preferably at least 60 %, and more preferably at least 70 % of the polymer particles in cross-sectional cuts of at least 90 % of the elements have a diameter in the range of 0.1 mm to 40.0 mm, preferably in the range of 0.5 mm to 35.0 mm, and more preferably in the range of 1.0 mm to 30.0 mm,

In a preferred embodiment of the method for producing a further sports surface, the interlockable elements are arranged such that a 10 m ² surface area of the foundation is superimposed with, in the range of 0.5 to 20, more preferably in the range of 1 to 15, even more preferably in the range of 2 to 10, and further preferably in the range of 2 to 5 interlockable elements. This preferred embodiment is a 105 ^th embodiment of the invention, that preferably depends on the 104 ^th em bodiment of the invention.

In a preferred embodiment of the method for producing a further sports surface, at least one or all of the 82 ^nd to 85 ^th embodiments apply to the foundation of the further sports surface. This preferred embodiment is a 106 ^th embodiment of the invention, that preferably depends on any of the 104 ^th to 105 ^th embodiments of the invention. In an aspect of the 106 ^th embodiment, it is preferred that at least one or all of the 82 ^nd to 85 ^th embodiments’ preferred aspects apply to the foundation of the further sports surface. All possible combinations of the 82 ^nd to 85 ^th embodi ments, and their preferred aspects, are explicitly disclosed, and preferred when applied to the 106 ^th embodiment.

In a preferred embodiment of the method for producing a further sports surface, the interlockable elements are arranged to cover at least 70 %, preferably at least 80 %, and more preferably at least 95 % of a surface of the foundation. This preferred embodiment is a 107 ^th embodiment of the invention, that preferably depends on any of the 104 ^th to 106 ^th embodiments of the invention.

In a preferred embodiment of the method for producing a further sports surface, the method does not comprise the step of applying a tension when arranging the interlockable elements on the foundation. This preferred embodiment is a 108 ^th embodiment of the invention, that preferably depends on any of the 104 ^th to 107 ^th embodiments of the invention.

In a preferred embodiment of the method for producing a further sports surface, the method further comprises the step of fastening at least one, preferably all, of the elements to the founda tion using a fastening means. This preferred embodiment is a 109 ^th embodiment of the invention, that preferably depends on any of the 104 ^th to 108 ^th embodiments of the invention. Examples of the fastening means include an adhesive, or a peg, preferably a metal peg, and a metal rod. If an adhesive is used, it is preferred that the adhesive is applied between the base layer and the foun dation.

In a preferred embodiment of the method for producing a further sports surface, the arranged interlockable elements are not covered with a layer comprising any of the following: grass, sports turf, synthetic turf, and wood, e.g. , plywood. This preferred embodiment is an 110 ^th embodiment of the invention, that preferably depends on any of the 104 ^th to 109 ^th embodiments of the inven tion.

A one-hundred-and-eleventh (111 ^th ) embodiment of the invention is a further sports surface ob tainable by a method, according to the invention, for producing a further sports surface, prefer ably a method according to any of the 104 ^th to 110 ^th embodiments of the invention. A one-hundred-and-twelfth (112 ^th ) embodiment of the invention is a use of a further sports sur face according to the invention, preferably a further sports surface according to any of the 92 ^nd to 103 ^rd , 104 ^th to 110 ^th , and 111 ^th embodiments, as at least one or all of the following: a netball court, a hockey field, preferably an indoor hockey field, a cricket pitch, and a basketball court.

A one-hundred-and-thirteenth (113 ^th ) embodiment of the invention is a use of a plurality of in- terlockable elements for producing a further sports surface, preferably at least one or all of the following: a tennis court, more preferably a clay tennis court, a netball court, a hockey field, preferably an indoor hockey field, a cricket pitch, and a basketball court.

Further aspects of the invention are described in more detail below.

Interlocking manner

An aspect of the invention is an interlockable unit that is adapted and arranged to engage at least one other interlockable unit in an interlocking manner. This “engagement in an interlocking manner” should be understood to mean that the interlockable unit can be arranged in contact with at least one other interlockable unit. E.g ., two interlockable units that have the shape of a square can be arranged in contact with each another by placing the interlockable units next to each other. In this aspect it is preferred that the interlockable unit has the shape of a square, a rectangle, a triangle, or a polygon. In the aspect of the “adapted and arranged to engage at least one other interlockable unit in an interlocking manner it is, however, more preferred that the interlockable unit has at least one protrusion that is adapted and arranged to mate with at least one indentation of at least one other interlockable unit. In this aspect it is preferred that the interlockable unit has at least one indentation that is adapted and arranged to mate with at least one protrusion of at least one other interlockable unit.

An aspect of the invention is a plurality of elements that are adapted and arranged to engage each other in an interlocking manner. This “engagement in an interlocking manner ” should be understood to mean that the elements can be arranged in contact with each other. E.g ., two ele ments that have the shape of a square can be arranged in contact with each another by placing the elements next to each other. In this aspect it is preferred that elements have the shape of a square, a rectangle, a triangle, or a polygon. In the aspect of the “adapted and arranged to en gage at least one other interlockable unit in an interlocking manner ”, it is, however, more pre ferred that at least one element has at least one protrusion that is adapted and arranged to mate with at least one indentation of at least one other element. In this aspect it is also preferred that at least one element has at least one indentation that is adapted and arranged to mate with at least one protrusion of at least one other element.

Superimposed

If a further layer, e.g, the further intermediate layer, is “superimposed” on a first layer, e.g, the first intermediate layer, this should be understood to mean that the further layer at least partially covers the first layer. This should, however, not be understood to mean that the first layer and the further layer have to touch each other. E.g., the further layer is superimposed on the first layer, wherein an additional layer is located between the first layer and the further layer, i.e., the first layer and the further layer both touch the intermediate layer, but the first layer and the further layer do not touch each other.

If the interlockable units are “superimposed” on a foundation, this should be understood to mean that the interlockable units at least partially cover the foundation. This should, however, not be understood to mean that the interlockable units and the foundation have to touch each other. E.g., the interlockable units are superimposed on the foundation, wherein an additional layer is between the interlockable units and the foundation, i.e., the interlockable units and the founda tion both touch the intermediate layer, but the interlockable units and the foundation do not touch each other.

Diameter of polymer particles

The diameter of the polymer particles is defined as illustrated in Figure IB. In an aspect of the invention, it is preferred that the diameter of at least 40 %, preferably at least 50 %, and more preferably at least 60 % of the polymer particles, in a cross-sectional cut of the base layer, is arranged along a length of the base layer. This should be understood to mean the following: an imaginary axis is orientated along a length of the base layer. A polymer particle is defined as being “arranged along a length of the base layer” if an angle enclosed between the diameter of the polymer particle and the imaginary axis is less than 45°. This applies, mutatis mutandis , to the diameters of polymer particles arranged along a length of an element of the plurality of ele ments.

Acrylate

An acrylate according to the invention should be understood to mean either an acrylate mono mer, an acrylate oligomer and acrylate polymer, or a combination of at least two thereof, wherein oligomers or polymers or both are preferred. Examples of an acrylate according to the invention is (poly)methyl methacrylate, butyl -acrylate, 2-ethylhexyl acrylate, glacial acrylic acid, glacial methacrylic acid, diacetone acrylamide, caprolactone-modified (meth)acrylate, vinyl trimethox- ysilane, methacryloxypropyltrimethoxysilane, vinyl acetate monomer, and vinyl neodecaonate, or combinations of two or more thereof. An example of an acrylate according to the invention is an acrylate resin.

Rubber

In an aspect of the interlockable unit, it is preferred that at least one or all of the following comprises less than 15 wt.-%, more preferably less than 10 wt.-%, even more preferably less than 5 wt.-%, and further preferably less than 1 wt.-%, based on a weight of the respective layer, of a rubber: a. the base layer, b. the first intermediate layer, c. the further intermediate layer, d. the surface layer. In the above, all possible combination of the features a. to d. are preferred aspects These combi nations are e.g., a; b; c; d; a, b; a, c; a, d; b, c; b, d; c, d; a, b, c; a, b, d; a, c, d; b, c, d; a, b, c, d. Examples of a rubber are natural rubber, and synthetic rubber, e.g. , ethylene propylene diene monomer rubber.

In an aspect of the plurality of elements, it is preferred that at least one or all of the following comprises less than 15 wt.-%, more preferably less than 10 wt.-%, even more preferably less than 5 wt.-%, and further preferably less than 1 wt.-%, based on a weight of the respective layer or element, of a rubber: a. at least one, preferably all, elements, b. the first intermediate layer, c. the further intermediate layer, d. the surface layer.

In the above, all possible combination of the features a. to d. are preferred aspects These combi nations are e.g., a; b; c; d; a, b; a, c; a, d; b, c; b, d; c, d; a, b, c; a, b, d; a, c, d; b, c, d; a, b, c, d. Examples of a rubber are natural rubber, and synthetic rubber, e.g, ethylene propylene diene monomer rubber.

Unbound particulated material

Particulated material that is “unbound” should be understood to mean particulated material that is not held together by an adhesive or a binder, e.g. , a cementitious binder or a bituminous binder.

Interlockable unit and plurality of elements

In an aspect of the invention, it is preferred that the interlockable unit does not comprise at least one support leg. In another aspect of the invention, it is preferred that at least 80 %, more pref erably at least 90 %, and further preferably all of the plurality of elements do not comprise at least one support leg. Coating of plurality of elements

In various aspects of the method for producing a plurality of interlockable units, the plurality of elements are coated with at least one layer, e.g ., the first intermediate layer, the further interme diate layer, and the surface layer. When an element of the plurality of elements is “coated” with a layer, should be understood to mean that the layer at least partially covers at least one or all of the following: a first outermost surface of the element, a further outermost surface of the element. It is, however, more preferred that the layer at least partially covers either the first outermost surface of the element, or the further outermost surface of the element.

When an element of the plurality of elements is “coated” with a layer, this should not be under stood to mean that the element and the layer have to touch each other. E.g ., a first outermost surface of an element is coated with a first layer, wherein a further layer is between the first outermost surface of the element and the first layer, /. e. , the first outermost surface of the element and the first layer both touch the further layer, but the first outermost surface of the element and the first layer do not touch each other.

Increasing the hardness of coating layer

In various aspect of the method for producing a plurality of interlockable units, a hardness of at least one coating layer, e.g. , the first intermediate layer, the further intermediate layer, and the surface layer, is increased. It is preferred to increase the hardness of the at least one coating layer by allowing the at least on coating layer to dry. In another aspect, the increase in hardness is obtained by crosslinking. Crosslinking can be accomplished by light irradiation, preferably with UV light, IR light or both, or by thermal treatment.

Obtaining of layers and elements

In an aspect of the invention, it is preferred to obtain the plurality of elements by compressing a plurality of polymer particles into a particle layer. In this aspect, it is preferred to bond the plu rality of particles by applying heat to the particle layer, such as thermal bonding. In another aspect of the invention, it is preferred to use recycled polymer particles to produce the plurality of elements. In another aspect of the invention, it is preferred to use excess polymer particles that result from manufacturing processes. A layer comprising a plurality of polymer particles can also be commercially obtained from e.g, Regupol BSW GmbH (Germany), such as Regupol ^® .

A first intermediate layer and a further intermediate layer that are suitable to the invention are commercially available from Enke-Werk, Johannes Enke GmbH & Co. KG (Germany) under the trade name Enkryl ^® .

A surface layer that is suitable to the invention is well-known the skilled person. Such a surface layer is commercially available from e.g. , ThorWorks Industries, Inc (USA), such as the Sports- Master “Ready-Mix Color” product, or Advanced Polymer Technology Corp. (USA), such as the Laykold ColorCoat product.

Obtaining of interlockable units

In the method for producing a plurality of interlockable units, the interlockable units are defined as the product that is obtained once all the method steps have been completed.

The invention is now illustrated by non-limiting examples and exemplifying embodiments.

FIGURES

List of figures

The figures serve to exemplify the present invention, and should not be viewed as limiting the invention. Note that the figures are not drawn to scale. Fig. 1 A: schematic illustration of a cross-sectional cut of an interlockable unit according to the invention, viewed from the side.

Fig. IB: schematic illustration of a diameter of a polymer particle in a base layer of an inter lockable unit according to the invention.

Fig. 1C: schematic illustration of an interlockable unit according to the invention, viewed from above. Fig. 2A: schematic illustration of a first sport surface according to the invention, viewed from above.

Fig. 2B: schematic illustration of a cross-sectional cut of an interlockable unit, located in a first sports surface according to the invention, viewed from the side.

Fig. 3: diagrammatic illustration of the steps of a first method for producing an interlockable unit, according to the invention.

Fig. 4: schematic illustration of a cross-sectional cut of a further sport surface according to the invention, viewed from side.

Description of figures

Fig. 1A shows a schematic illustration of a cross-sectional cut of an interlockable unit 100 ac cording to the invention, viewed from the side. The interlockable unit 100 has a first outermost surface 101 and a further outermost surface 102, wherein the further outermost surface 102 is opposite the first outermost surface 101. The interlockable unit 100 also has a plurality of per forations, e.g, 103a and 103b. The perforation 103a has an opening on the first outermost surface 101. The perforation 103b has openings on both the first outermost surface 101 and the further outermost surface 102, i.e ., the perforation 103b extends from the first outermost surface 101 to the further outermost surface 102. Furthermore, the plurality of perforations 103 are perpendic ular to the first outermost surface 101 and the further outermost surface 102. Fig. 1 A also shows that the interlockable unit 100 has a base layer 104 that comprises a plurality of polymer parti cles, e.g. , 108a and 108b, a first intermediate layer 105, a further intermediate layer 106, and a surface layer 107. Fig.lA also shows that the first intermediate layer 105 only covers one surface of the base layer 104, that the further intermediate layer 106 only covers one surface of the first intermediate layer 105, and that the surface layer 107 only covers one surface of the further intermediate layer 106. Therefore, e.g. , the first inter mediate layer 105 does not completely surround the base layer 104.

Fig. IB is a schematic illustration of how a diameter of a polymer particle is measured. Fig. IB shows a section of a cross-sectional cut of a base layer 104, where the base layer 104 is part of an interlockable unit 100 according to the invention. The base layer 104 comprises a polymer particle 108. A diameter 109 of the polymer particle 108 is defined as the longest length of the polymer particle 108 in the cross-sectional cut. In other words, the diameter 109 is measured from the two points on a circumference of the polymer particle 108 that are the furthest apart. The diameter of a polymer particle comprised in an element of a plurality of elements is defined in the same manner as the diameter of a polymer particle in the base layer.

Fig. 1C shows a schematic illustration of an interlockable unit 100 according to the invention, viewed from above. It can be seen that a plurality of perforations 103 is in the form of slits. Furthermore, this plurality of perforations 103 cover less than 30 % of a surface area of a further outermost surface 102 of the interlockable unit 100. The interlockable unit 100 also has six pro trusions, e.g ., 110, and six indentations, e.g. , 111, arranged around an edge of the interlockable unit 100. The indentation and protrusions are adapted and arranged to, respectively, mate with protrusions and indentations of at least one other interlockable unit. Fig.1C also shows how the dimensions of the interlockable unit are measured. In Fig. 1C, the interlockable unit 100 has a first dimension 112 and a further dimension 113. Although defined as such in Fig. 1C, it is not a requirement that the longer of the two dimensions should be defined as the further dimension. It is however, preferred. Fig. 1C also shows a first dimension 114 and a further dimension 116 of a protrusion, as well as a first dimension 114 and a further dimension 117 of an indentation. Although defined as such in Fig. 1C, it is not a requirement that the first dimensions 114 should be defined perpendicular to a side of the interlockable unit 100 from which the protrusions pro trudes. It is however, preferred. Although defined as such in Fig. 1C, it is not a requirement that the first dimensions 116 should be defined perpendicular to a side of the interlockable unit 100 into which the indentation indents. It is however, preferred.

Fig. 2A shows a schematic illustration of a first sport surface 200 according to the invention, viewed from above. A plurality of interlockable units, e.g. , 218a and 218b, are arranged in an interlocking manner. The interlockable units are arranged such that the protrusions and indenta tions of an interlockable unit mate, respectively, with the indentations and protrusions of neigh bouring interlockable units. Furthermore, the interlockable units 218 have a plurality of perfo rations, e.g. , 203 that have openings on a further outermost surface 202 of the first sports surface. Fig. 2B shows a schematic illustration of a cross-sectional cut of an interlockable unit (e.g, 218a) located in the first sports surface 200, viewed from the side. The interlockable unit has the same structure as the interlockable unit 100 in Fig. 1 A. However, Fig. 2B shows that a founda tion 219 of the first sports surface is located below the interlockable unit.

Fig. 3 shows diagrammatic illustration of the steps of a first method 300, according to the inven tion, for producing an interlockable unit. In step 301 a plurality of elements are provided. The plurality of elements are adapted and arranged to engage each other in an interlocking manner. Furthermore, the plurality of elements each comprise a plurality of perforations. In step 302, the plurality of elements are arranged in an interlocking manner. In step 305, the plurality of ele ments are coated with a further intermediate layer. In step 306, the hardness of the further inter mediate layer is increased. In step 309, the plurality of interlockable units is obtained by sepa rating the coated and interlocked plurality of elements. Fig. 3 also shows the optional steps 303 and 304, which are performed prior to step 305. In step 303, the plurality of elements are coated with a first intermediate layer. In step 304, the hardness of the first intermediate layer is in creased. Fig. 3 also shows the optional steps 307 and 308, which are performed after step 306, but before step 309. In step 307, the plurality of elements are coated with a surface layer. In step 308, the hardness of the surface layer is increased.

Fig. 4 shows a schematic illustration of a cross-sectional cut of a further sport surface 400 ac cording to the invention, viewed from side. A plurality of interlockable elements, e.g., 420a and 420b, are arranged in an interlocking manner. The interlockable elements 420 have indentations and protrusions similar to the indentations and protrusions of the interlockable units of Fig. 1C. The interlockable elements 420 are arranged such that the protrusions and indentations of an interlockable element mate, respectively, with the indentations and protrusions of neighbouring interlockable elements. The interlockable elements 420 form a base layer that comprises a plu rality of polymer particles, e.g. , 408a and 408b. The further sports surface 400 also has a first intermediate layer 405, a further intermediate layer 406, and a surface layer 407. Fig. 4 also shows that a foundation 419 of the further sports surface 400 is located below the interlockable elements 420. The interlockable elements 420 are secured to the foundation 419 using pegs 421 (for illustration purposes, only a single peg is shown). Alternatively, or additionally, the inter lockable elements 420 may also be secured using an adhesive located on a first outermost surface 401 of the elements. Although not shown in Fig. 4, the outermost surface 401 of an element may also be coated with the first intermediate layer 405, the further intermediate layer 406, or both.

EXAMPLES

The invention is illustrated further by way of examples. The invention is not restricted to the examples.

Inventive example 1

A plurality of elements are provided. Each element has a first dimension of 2.29 m, and a further dimension of 0.94 m. Furthermore, each element has six protrusions and six indentations. The protrusions and indentations are arranged in the same manner as shown for the interlockable unit in Fig. 1C. The protrusions and indentations of an element are adapted and arranged to mate with the indentations and protrusions, respectively, of the other elements. The first dimension of the protrusions and indentations is 40 mm, while the further dimension of the protrusions and indentations is 115 mm. The dimensions are chosen in the same manner as shown for the inter lockable unit in Fig. 1C. Each of the elements also have a plurality of perforations that extend from a first outermost surface of the element to a further outermost surface of the element. Fur thermore, the perforations are arranged perpendicular to the first and further outermost surfaces of the element. The perforations cover less than 20 % of a surface area of the first outermost surface of the element. The perforations cover less than 20 % of a surface area of the further outermost surface of the element.

Each element comprises polyethylene particles, where at least 75 % of the polyethylene particles have a diameter in the range of 2.0 mm to 29.0 mm. Furthermore, at least 75 % of the polyeth ylene particles are closed-cell foam particles.

The plurality of elements are arranged in an interlocking manner, and then coated with a further intermediate layer. The further intermediate layer comprises acrylic, and is obtained from Enke- Werk, Johannes Enke GmbH & Co. KG (Germany) under the trade name Enkryl ^® . After the further intermediate layer has dried, the plurality of elements are coated with a surface layer. The surface layer is the SportsMaster “Ready-Mix Color” product obtained fromThorWorks Industries, Inc (USA).

After the surface layer has dried, the plurality of interlocked elements are separated by human operators, thereby leading to a plurality of interlockable units being obtained. The plurality of interlocked elements are separated by applying pressure to the interlocked elements. The pres sure is applied by hand.

Inventive example 2 The interlockable units obtained from inventive example 1 are superimposed on a foundation in an interlocking manner. The foundation comprises unbound construction aggregate in the form of sand and gravel. Furthermore, the interlocked units touch the foundation, but are not adhered to the foundation. Therefore, the interlocked units can be easily separated and removed. A tennis court is obtained by superimposing the interlocked units on the foundation.

Comparative example 1

A tennis court is obtained by coating a foundation with a surface layer. The foundation is a concrete layer. The surface layer is the SportsMaster “Ready-Mix Color” product obtained fromThorWorks Industries, Inc (USA).

Table 1 shows the advantages that a tennis court, produced using the interlockable units accord ing to the present invention, has over a prior art tennis court. A “+” indicates an improvement in the desired effect, while a indicates a decrease in the desired effect. Table 1: comparison of inventive example 2 with comparative example 1

• Water infiltration rate - the rate at which water can be drained through the surface of the tennis court. It is desired to have a higher water infiltration rate.

• Shock absorption - how well the tennis court can reduce impact force. It is desired to have a higher shock absorption.

• Energy restitution - the amount of energy that the tennis court returns to a player. It is desired to have an intermediate energy restitution, /. e. , in the range of 45 % to 70 %.

• Removable - whether the tennis court can be disassembled and reassembled. It is desired to have a removable tennis court.

• Maintenance - the amount of maintenance required for tennis court. For the tennis court according to the invention, damaged interlockable units can be individually and quickly replaced. It is desired to have a reduced maintenance.

• Production speed - the speed with which the tennis court can be produced. It is desired to have a higher production speed.

• Robustness - how well the tennis court can adapt to changes in temperature. It is desired to have a higher robustness, i.e., the tennis court should be less influenced by expansion or contraction due to changes in the temperature.

• Recyclability - how easily the tennis court can be recycled when the tennis court reaches the end of its lifetime. It is desired to have a higher recyclability.

Inventive example 3

A plurality of elements are provided. Each element has a first dimension of 2.29 m, a further dimension of 0.94 m, a thickness of 15 mm, and a density of 300 g/cm ³ . Furthermore, each element has six protrusions and six indentations. The protrusions and indentations are arranged in the same manner as shown for the interlockable unit in Fig. 1C. The protrusions and indenta tions of an element are adapted and arranged to mate with the indentations and protrusions, respectively, of the other elements. The first dimension of the protrusions and indentations is 40 mm, while the further dimension of the protrusions and indentations is 115 mm. The dimensions are chosen in the same manner as shown for the interlockable unit in Fig. 1C. The elements do not have any perforations.

Each element comprises polyethylene particles, where at least 75 % of the polyethylene particles have a diameter in the range of 2.0 mm to 29.0 mm. Furthermore, at least 75 % of the polyeth ylene particles are closed-cell foam particles.

The plurality of elements are superimposed on a foundation in an interlocking manner. The foundation comprises unbound construction aggregate in the form of sand and gravel. The ele ments are secured to the formation using metal pegs.

The plurality of elements are then coated with a further intermediate layer. The further interme diate layer comprises acrylic, and is obtained from Enke-Werk, Johannes Enke GmbH & Co. KG (Germany) under the trade name Enkryl®. After the further intermediate layer has dried, the plurality of elements are covered with a surface layer. The surface layer, with a thickness of 1 - 2 mm is obtained by applying Probitano Elastic Self-Leveling commercially obtainable from SEIRE PRODUCTS, SL, Spain. No sand is applied in this surface layer. After 24 hours at am bient conditions, the pitch marking of a basketball court were applied.

Comparative example 2

An outdoor basketball court is obtained by covering a foundation with a surface layer. The flat foundation is an even concrete layer, wherein the concrete layer was provided in an antifreeze casing and was dried over 30 days at ambient conditions. The surface layer has a thickness of 1 - 2 mm and is obtained by applying Probitano Elastic Self-Leveling commercially obtainable from SEIRE PRODUCTS, SL, Spain. No sand is applied in this surface layer. After 24 hours at ambient conditions, the pitch marking of a basketball court were applied.

Table 2 shows the advantages that a basketball court, produced using the interlockable elements, has over a prior art basketball court. A “+” indicates an improvement in the desired effect, while a indicates a decrease in the desired effect. Table 2: comparison of inventive example 3 with comparative example 2

The effects in Table 2 have the same meaning as in Table 1. In addition, Table 2 also has the following effect:

• CO 2 emission - pertains to the total CO2 emitted in order to build the sport court.

TEST METHODS

The test methods which follow were utilized within the context of the invention. Unless stated otherwise, the measurements were conducted at an ambient temperature of 23 °C, an ambient air pressure of 100 kPa (0.986 atm) and a relative air humidity of 50 %. Diameter of polymer particles

To determine the diameter of the polymer particles in a base layer, a cross-sectional cut is made perpendicular to the base layer. To determine whether the polymer particles are arranged along a length of the base layer, a cross-sectional cut is also made perpendicular to the base layer. To determine the diameter of the polymer particles in an element, a cross-sectional cut is made perpendicular to the element. To determine whether the polymer particles are arranged along a length of the element, a cross-sectional cut is also made perpendicular to the element.

Base layer

The properties of the base layer are measured according to the standards given in the table below:

Property of base layer Standard Ultimate tensile strength DIN EN 12230:2003-07

Ultimate tensile strength after aging DIN EN 12230:2003-07, with the aging per formed in air

Water infiltration rate DIN EN 12616:2013-12, Method A Shock absorption EN 14808:2005 Energy restitution ASTM F3189-17, and measured using an Ad vanced Artificial Athlete

Vertical deformation EN 14809:2005 Shock absorption DIN EN 14808:2006-03 Mass per unit area EN-ISO 9864:2005

Further intermediate layer

Elongation at yield and tensile strength of the intermediate layers are measured according to the standard ISO 527-3:2019.

Particle size

The size of the particulated material is measured according to the standard BS 1796-1 : 1989. For the sieving analysis, at least 6 sieves are employed. Shore 00 hardness

Shore 00 hardness is measured according to the standard ASTM D2240.

Density

The density p of the base layer is determined by the formula p = pA / /, where /¾ is the mass per unit area of the base layer, and / is the average thickness of the base layer. REFERENCE LIST Interlockable unit First outermost surface Further outermost surface Plurality of perforations Base layer First intermediate layer Further intermediate layer Surface layer Plurality of polymer particles Diameter of polymer particle Protrusion Indentation First dimension of interlockable unit Further dimension of interlockable unit First dimension of protrusion Further dimension of protrusion First dimension of indentation Further dimension of indentation First sports surface First outermost surface Further outermost surface Plurality of perforations Base layer First intermediate layer Further intermediate layer Surface layer Plurality of polymer particles Interlocking units Foundation A first method for producing a plurality of interlockable units Provide a plurality of elements Arrange the plurality of elements in an inter locking manner Coat the plurality of elements with a first in termediate layer Increase the hardness of the first intermedi ate layer Coat the plurality of elements with a further intermediate layer Increase the hardness of the further interme diate layer Coat the plurality of elements with a surface layer Increase the hardness of the surface layer Obtain plurality of interlockable units by separating coated and interlocked plurality of elements Further sports surface First outermost surface First intermediate layer Further intermediate layer Surface layer Plurality of polymer particles Foundation Interlockable elements Peg