A double-sided thermoplastic mattress in the form of a sleeping pad comprising at least one mattress layer made of thermoplastic fibres, a method of manufacturing of the mattress layers of the said mattress and a device to implement the said method

The subject-matter of the invention is a double-sided thermoplastic mattress in the form of a sleeping pad comprising at least one mattress layer made of thermoplastic fibres, a method of manufacturing of the mattress layers of the said mattress and a device to implement the said method.

In accordance with the prior art, industrial manufacture of mattresses requires a number of components (e.g. mattress toppers, chemical foams, springs) and materials to achieve the properties desired for the comfort of the end-user. The design of single -piece mattresses provides for a single component. This group of mattresses includes, for example, latex mattresses made of a single layer of latex or foam mattresses made of polyurethane foam. On the other hand, multi-component mattresses are the ones made of different components (e.g. a combination of foam and springs).

Mattresses made of chemical foam are known from the prior art. For example, utility model description PL68734 Y1 provides for a double-sided foam mattress in a cover, having the form of a rectangular sleeping pad with horizontal channels located longitudinally and transversely crossing each other. Whereby, spatial elements are inseparably attached to the longer sides of the said mattress pad to form rectangular planes of the mattress and its edges, which have the shape of a cuboid, and are made of a foam much more firm than the foam of which the mattress pad is made, and the channels are located on the both opposite surfaces of the mattress pad, the channels on one side of the mattress pad being deeper than the channels located on its other side.

Utility design PL63662 Y 1 describes a mattress consisting of a lower base part (A) made of a traditional resilient polyurethane foam, whose upper surface is formed by evenly distributed depressions and protuberances, with the tops of the protuberances touching the upper part (B), whereby the hollow recesses contain empty spaces; in addition, upper part (B) is made of a foam material, which is characterised by low elasticity with high cushioning capacity and slow return to its original shape after deformation.

On the other hand, Canadian patent application CA2958348 describes a mattress set consisting of a layer of polyurethane foam comprising a porous foam body containing a plurality of air pockets; and a gel and an antimicrobial agent mixed and soaked into the foam in such a way that the gel and the antimicrobial agent occupy the air pockets of the porous foam body. Whereby, the antimicrobial agent comprises a polymer in an amount of 90 to 99.9 weight percent, an oxidant in an amount of 0.004 to 1 weight percent and metallic silver in an amount of 0.002 to 1 weight percent, the weight percent being based on the total weight of the antimicrobial agent. Currently, a number of methods are available for the industrial manufacture of mattresses. For example, document CN111188125 discloses a nano-antimicrobial medical mattress and a method of manufacturing it. Whereby, the disclosed method of producing antimicrobial mattresses includes the following steps: degumming a sheet of coconut fibre and processing it to obtain coconut fibre; immersing the coconut fibre in a methylthiodiazomethane solution, mixing, followed by immersion in solvents and then loading the coconut fibre with methylthiodiazomethane in a heat treatment of the coconut fibre, followed by washing and drying to obtain a modified coconut fibre. The modified coconut fibre is then exposed to the nanosilver dispersion in the conditions with an increased temperature. The fibres are then centrifuged and washed to obtain nanosilver-modified coconut palm fibre composites. The silver- modified coconut fibre composites and kapok fibre were then blended to produce the blended fibres. A board was then produced of the resulting blended fibres together with a polyurethane solution by means of a cold pre-moulding involving a dedicated board followed by a hot moulding process.

International patent application WO2017199474 describes a method of producing a three-dimensional fibre conjugate in which multiple thermoplastic resin fibres (meltblown filaments) in a meltblown state are three-dimensionally combined and bonded together as a cushion or mattress material with high detruding capacities. Furthermore, the document in question discloses a device for producing a three- dimensional filament conjugate. Whereby, the said device includes a device for delivery of fused filament which discharges fused filaments from each of a plurality of nozzles; and a three-dimensional conjugate-forming device for forming a three-dimensional filament conjugate by fusing and bonding the fused filament group discharged from the first device. The device that delivers the fused filament (fibre) includes an opening/closing unit that opens/closes a plurality of specific nozzles, which are a plurality of nozzles arranged in a predetermined direction, and the opening/closing unit includes an aperture element that can move between an open position that opens the aperture and a closed position that closes the aperture and provides sliding on the surface containing the aperture, and the opening and closing is performed by moving the aperture element. The aperture element has an opening corresponding to each of the specified nozzles and is formed so that it can move in a specified direction. The opening position is the position in which the opening overlaps the corresponding specific nozzle. According to this configuration, the three-dimensional conjugate of the filament can be easily produced by adjusting its thickness, hardness or the like dimensions. In contrast, the disclosed method of producing a three-dimensional filament conjugate comprises: extruding a molten thermoplastic resin from a plurality of horizontally arranged nozzles directed vertically downwards, then dropping the molten filament into a cooling water to form a loop, and a three-dimensionally fusing by fusing a plurality of loop-formed molten filaments together. Each molten bonded fibre connected to each other through fusion is transferred to the back side for cooling and a three-dimensional filament conjugate is moulded so that it is continuous in the direction of transfer. The three-dimensional filament conjugate is cut to each of the lengths corresponding to specific product dimensions to obtain a three-dimensional filament conjugate for the product.

Mattresses that are commercially available at present do not meet the needs of society, as they have limited air permeability, generate heat and are difficult to clean and their cleaning is time-consuming.

Therefore, the aim of the invention is to develop a new device, a method for producing a mattress layer for mattresses and mattresses themselves containing said mattress layer which would be devoid of the above disadvantages.

The essence of the invention is a double-sided thermoplastic mattress in the form of a sleeping pad comprising at least one mattress layer of thermoplastic fibres, characterised in that it has a resilience of 40 to 70%, a water permeability at least 90% and each layer has a density of 30 to 190 kg/m ³ .

Advantageously, each fibre of the mattress layer is coated with silver ions.

Advantageously, the permeability of the mattress to water is at least 95%.

Advantageously, the mattress according to the invention comprises one to three mattress layers.

Advantageously, the air velocity after passing through the mattress is at least 5 km/h with the input velocity of 18.72 km/h.

Advantageously, the total drying time of the mattress made according to the invention is a maximum of 24 hours with the drying time of at least 80% being 1 hour.

Advantageously, the mattress made according to the invention has a heat loss rate of at least 30% in 10 minutes, advantageously 50%.

Advantageously, the mattress manufactured according to the invention absorbs less than 38% water.

Another essential feature of the invention is a method for the continuous production of the thermoplastic fibre mattress layer of a mattress manufactured according to the invention, characterised in that the manufacturing comprises the following steps: a) thermoplastic granules are supplied to raw material infeed unit of the extruder; b) the granules are heated by heaters of the heating zones of auger of the extruder; c) the fibres are extruded through a plurality of downward-facing manufacturing nozzles of the extruder; d) As an option, silver ions are dispersed on the surface of the extruded thermoplastic fibres when they exit manufacturing nozzles. The silver ions are dispersed through at least two opposing lateral dispersing nozzles installed on the cooling tank housing perpendicularly to manufacturing nozzles below their mouth; e) the fibres are heated in the outer vertical heaters zone at a temperature of 150°C-285°C; f) the thermoplastic fibres are transferred to cooling tank; g) the fibre conjugate is moulded to take specific shape on moulding rollers of cooling tank for 45 sec. to 5 minutes and the moulded conjugate is fed successively onto infeed rollers and infeed-receiving belt connecting the cooling tank with post-heating furnace; h) the moulded material is transferred to the heating furnace via the infeed-receiving belt; i) the moulded conjugate is subjected to a temperature of 120-350 °C in the reheating furnace for 45 sec. to 5 minutes; j) the moulded conjugate is received and trimmed at the furnace outlet by infeed-receiving unit, which is equipped with edge knives.

Advantageously in step e), the fibres are heated in the outer vertical heaters zone at 230-250 °C; advantageously at 230 °C.

Advantageously in step i), the moulded conjugate is heated at the temperature of 200-288 °C, advantageously at 240 °C.

Advantageously, the method according to the invention comprises step i'), wherein, after it exits the furnace, the moulded conjugate is subjected to final heating from terminal hot air nozzles at a temperature of 150 to 350 °C, advantageously at 200-290 °C.

A further essential feature according to the invention is a device for producing a thermoplastic fibre mattress layer for the mattress according to the invention, comprising an extruder unit connected by a gearbox to a motor and equipped with an auger comprising heating zones; the auger is connected to a multi-nozzle extruder equipped with built-in heaters; a cooling tank located below the manufacturing nozzles of the extruder and the feed-collection unit, characterised in that on the housing of the cooling tank, at least two opposed lateral dispersing nozzles are mounted above at least two opposed outer vertical heaters; whereby, the spacing of the said dispersing nozzles and outer vertical heaters being wider than the spacing of the extruder manufacturing nozzles; the cooling tank is provided with moulding and feed rollers and with a feed-receiving belt connecting the said cooling tank with a postheating furnace with an infeed-receiving unit located downstream the furnace. Advantageously, the auger unit is equipped with seven heating zones, each of which is equipped with a cooling fan.

Advantageously, the diameter of each of the plurality of the dispersing nozzles is between 0.6 mm and 1.5 mm.

Advantageously, the diameter of some of the dispersing nozzles is 0.6 mm while the diameter of the other dispersing nozzles is greater than 0.6 mm, advantageously 0.7 mm or 1.00 mm.

Advantageously, at the outlet of the post-heating furnace, terminal hot air nozzles are placed.

The invention provides the following advantages:

• The additional moulding in the furnace in accordance with the method provided for by the invention provides improved bonding between the individual filaments, which results in a greater durability of the produced mattress material in case of long-term use and improves its physical properties - i.e. provides a better fibre bonding, which reduces the level of deformation in mattresses and improves their resilience. In addition, because the connection between the individual fibres is stronger, the conjugate is more resistant to damage occurring if someone would like to damage mechanically the mattress layer e.g. through digging their finger into the structure of the mattress layer;

• The stage of heating the extruded fibres in the outer vertical heaters zone further stabilises their structure, protects the fibres from premature cooling as they leave the nozzle and flow into the water, increases the extent to which the threads are twisted and, in the silver-ion-coating variants, ensures increased binding of the silver ions to the surface of the thermoplastic fibres;

• After two years of use, the deformation rate of the mattress only falls within 25%;

• Both the mattresses and the mattress layers according to the invention manufactured using the method according to the invention are widely applicable for industrial manufacturing. In particular, they can be intended for the manufacture of mattresses for humans or animal beds, or even cushions, headrests, seats or overlays for an existing mattress;

• The mattress according to the invention allows absorbing heat from the user’s body. The resulting temperature is then transferred through the structure of the mattress;

• The structure of the material layers of the mattress according to the invention ensures air throughput and the exchange of warm air for cold air;

• The mattress according to the invention is characterised by high resilience (ranging from 40 to 70%);

• The mattress according to the invention absorbs less than 38% water.

• The mattress layers of the mattress according to the invention are characterised by a high water throughput of 99 to 99.8%; • High air throughput, i.e. the amount of air diverted from one side of the mattress that has passed to the other side of the mattress, reaching up to 90%; It is worth noting that some of the air bounces back, or propagates in a direction transverse to the direction from which it is blown into the mattress;

• The mattress according to the invention is easy to clean, since the total drying time of its mattress layer does not exceed 18 hours, and within 1 hour, the mattress is dry in 85%; whereby, the drying time was determined after water been shaken/squeezed off the mattress layer for 10 seconds subsequently to the mattress layer fully absorbing water;

• Advantageously, each fibre of the mattress layer of the mattress according to the invention is modified with silver ions, which adds antibacterial properties to the mattress; furthermore, because each fibre of the mattress material is coated with silver ions, the entire body, rather than only the surface of the mattress, has antibacterial properties.

A detailed description of the embodiments of the invention is provided below.

Whereby, within the meaning of the invention, phrase "in an embodiment" is to be understood as one or more embodiments. Furthermore, the features present in the various embodiments may be combined with each other. In this application, the descriptions of the embodiments of the invention are provided by way of example and are not intended to limit the scope of the invention. The described embodiments include various features, not all of which are required in all embodiments of the invention. Some embodiments use only some of the features or possible combinations of features. The described variants of the embodiments of the invention and the embodiments of the invention comprising different combinations of the features mentioned in the described embodiments will come to the mind of the persons skilled in the art. The scope of the invention is limited only by the claims.

In the first aspect, the invention covers a double-sided mattress made of thermoplastic material in the form of a sleeping pad comprising at least one mattress layer made of thermoplastic fibres, characterised in that it has a resilience of 40 to 70 per cent, a water permeability of at least 90 per cent and each layer has a density of 30 to 190 kg/m ³ .

Both the mattresses and the mattress layers according to the invention manufactured using the method according to the invention are widely applicable for industrial manufacturing. In particular, they can be intended for the manufacture of mattresses for humans or animal beds. Another envisaged potential use of the mattress according to the invention is a pillow, headrest, seat or overlay for an existing mattress.

In one embodiment, the mattress comprises a single mattress layer. In another one, the mattress comprises two mattress layers, whereby said layers may be identical or different. In another embodiment, the mattress according to the invention comprises three mattress layers, wherein said mattress layers may be identical or different. In one embodiment, the resilience of the mattress according to the invention is 40%, whereby in another one, the resilience is 44%. In yet another embodiment, the resilience is at least 50%, advantageously 52% and advantageously 54%. In another embodiment, the resilience of the mattress is at least 60%. In another embodiment, the resilience of the mattress according to the invention is 70%.

In some embodiments, the water throughput of the mattress according to the invention is 93%. In other embodiments, the water throughput of the mattress according to the invention is 95%. In other embodiments, the water throughput of the mattress according to the invention is 98%. In an advantageous embodiment, the water throughput through the mattress is 99.5%. In another embodiment, the water throughput through the mattress is 99.99%.

In one embodiment, the heat loss rate through the mattress according to the invention is at least 30%, advantageously 50%.

In one embodiment, the mattress according to the invention absorbs less than 38% water.

In some embodiments, each fibre of the mattress layer is coated with silver ions. In some embodiments, the mattress according to the invention comprises silver in an amount ranging from 0.00005% to 0.0001% by the weight of the filling of the entire mattress.

In some embodiments, the mattress layer is made of fibres of uniform diameter. In some embodiments, the diameter of the fibres of the mattress layer is 0.6 mm. In other embodiments, the diameter of the fibres of the mattress layer is 0.7 mm or 0.8 mm or 0.9 mm or 1.00 mm or 1.1 mm or 1.5 mm, respectively.

In other embodiments, the mattress layer of the mattress according to the invention is made of fibres of different diameters. In advantageous embodiments, the fibres of which the mattress layer is made come in two different diameters. In advantageous embodiments, the first diameter is 0.7 mm and the other one is larger than 0.7 mm and may be, for example, 1.00 mm. In another embodiment, the first diameter is 0.6 mm and the other one is greater than 0.7 mm and may be, for example, 0.7 mm. The first diameter is 0.6 mm and the other one is greater than 0.7 mm and may be, for example, 1.5 mm.

In some embodiments, the time for complete drying of the mattress layer of the mattress according to the invention after prior shaking of the mattress for 10 seconds is up to 24 h. In some embodiments, after 1 h the mattress is 80% dry. In the advantageous embodiment, the mattress dries 80-93% after 1 hour. In the advantageous embodiment, the mattress dries 99% after 1 hour. In the advantageous embodiment, the mattress dries 83-96% after 2 hours. In the advantageous embodiment, the mattress dries 100% after 2 hours. In the advantageous embodiment, the mattress dries 89-99% after 6 hours. In the advantageous embodiment, the mattress dries 100% after 6 hours. In the advantageous embodiment, the mattress dries 96-100% after 18 hours. Whereby, the drying time was determined after water had been shaken/ squeezed off the mattress layer for 10 seconds subsequently to the mattress layer fully absorbing water.

In some embodiments, the velocity of air after it has passed through the mattress is at least 5 km/h with the input velocity of 18.72 km/h. In the advantageous embodiments, the velocity of the air after it has passed through the mattress is 5.14 km/h or 7.23km/h or 14.25 km/h.

In an advantageous exemplary embodiment of the invention, the mattress layers according to the invention were used to manufacture a double-sided mattress. The mattress layers can be placed in a cover.

In an advantageous exemplary embodiment of the invention, the double -sided mattress made of thermoplastic materials comes in the form of a rectangular sleeping pad, which can be intended both for human or animal use, in particular for pets (such as, for example, dogs or cats).

The mattress according to the invention comprising mattress layers manufactured using the method according to the invention consists of at least one mattress layer.

In an advantageous exemplary embodiment, the mattress may consist of a single mattress layer. In another embodiment, the mattress according to the invention consists of two mattress layers. In another embodiment, the mattress according to the invention consists of three mattress layers. In another embodiment of the invention, the mattress according to the invention consists of six mattress layers. Whereby, it is also possible to manufacture mattress consisting of more mattress layers.

Whereby, in accordance with the invention, a single mattress may comprise the same or different mattress layers. Whereby, the said different mattress layers may differ from each other in e.g. dimensions (i.e. length, width, density), resilience or density.

Furthermore, the individual mattress layers can be stacked on top of each other, side by side or in a combination of these ways.

In an advantageous exemplary embodiment of the invention, the mattress layer produced using the method according to the invention is used to produce a double-sided mattress according to the invention with a modular structure, where a mattress layer produced by the method according to the invention, which performs the function of a panel, is referred to as a "module". Several panels arranged in one plane make it possible to select different modules as desired. The multiple panels may also be arranged in multiple layers, each of which may contain two or more panels.

In an exemplary embodiment, the mattress is made of six modules (panels), each of which is a mattress layer made using the method according to the invention. Whereby, the said six modules are arranged in two layers (three modules in each layer). In an exemplary embodiment, the mattress is made of six modules (panels), each of which is a mattress layer made using the method according to the invention. Whereby, said six modules are arranged in two layers (three modules in each layer) and the middle module (panel) of the upper layer has an increased density with respect to the other two panels of the upper layer. This is for the sake of a lesser sinking of the lumbar section and an increased comfort for some people.

In an exemplary embodiment, the mattress is made of six modules (panels), each of which is a mattress layer made using the method according to the invention. Whereby, said six modules are arranged in two layers (three modules in each layer) and the middle module (panel) of the upper layer has an increased density with respect to the other two panels of the upper layer. In contrast, the middle panel of the bottom layer has a reduced density relative to the other two panels of the bottom layer.

Thanks to the modular construction with the use of panels, we can facilitate transport of the mattress and, in a modular way, choose which density of the mattress is best for which part of the body. This ensures that the user of the mattress can select the modules as desired. For example, a person may choose that the “top” section, on which the head and shoulders of a person normally rest during sleep, has a greater firmness and lower resilience than the section on which the person's feet are located.

In the advantageous exemplary embodiment, the modular mattress contains two layers, with three panels in each layer.

In an advantageous exemplary embodiment, a mattress comprising mattress layers made using the method according to the invention exhibits a resilience of 40 to 70%. Furthermore, each layer of the said mattress has a density ranging from 30 to 190 kg/m3, whereby each fibre of the mattress layer is coated with silver ions. The air permeability of the mattress according to the invention will be 100%.

However, in an exemplary embodiment, the mattress according to the invention has an air throughput between 70% and 98%. In another exemplary embodiment, the mattress according to the invention is characterised by an air throughput of 80-94%.

In one exemplary embodiment, a double-sided mattress measuring 120x200 cm with a resilience of 55% contains a single mattress layer made according to the invention with a thickness of 11 cm and a density of 80 kg/m3. Its air throughput, on the other hand, is 92%.

In one exemplary embodiment, a double-sided mattress measuring 180x200 cm with resilience of 60% contains two mattress layers made according to the invention with the thickness of 25 cm and density of 120 kg/m3.

In one exemplary version, a double-sided mattress measuring 120x60 cm with a resilience of 50% contains a single mattress layer made according to the invention with the thickness of 11 cm. In another exemplary embodiment, the mattress according to the invention is a double-sided mattress measuring 1.40 x 0.66 m with a resilience of 48% containing two mattress layers each fibre of which is coated with silver ions. Whereby, each layer has a thickness of 6 cm and a density of 100 kg/m3. Its air throughput, on the other hand, is 90%.

In a further exemplary embodiment, the mattress according to the invention is a double-sided mattress measuring 120x200 cm with a resilience of 60%, containing a single mattress layer with a thickness of 11 cm and a density of 120 kg/m3. Whereby, each fibre of the mattress layer is coated with silver ions. Its air throughput, on the other hand, is 88%.

In a further exemplary embodiment, the mattress according to the invention is a double-sided mattress measuring 180x200cm with a resilience of 60%. The mattress contains three mattress layers with a total thickness of 25 and a density of 120 kg/m3 (two layers each 10 cm thick and one having a thickness of 5 cm). The mattress consists of three layers stacked on top of each other and has an air throughput of 82%.

In addition, the inventors carried out a number of tests to check the durability of the mattress according to the invention. The ageing tests carried out showed that the deformation rate of the mattress according to the invention containing mattress layers made using the method according to the invention does not exceed 10% after 10 years.

In a further aspect, the invention comprises a method of manufacturing mattress layers forming a mattress according to the invention.

In one embodiment, the method of manufacturing a mattress layer of thermoplastic fibres according to the invention is a continuous process.

In an advantageous embodiment, the feedstock constituting the material for producing the mattress layer may be Affinity 1280G, LLDPE, Braskem PP C123-01N, DOW™ LDPE 150ELDPE, another thermoplastic raw material or various combinations of known thermoplastic raw materials.

In advantageous exemplary embodiment of the method according to the invention, the granulate in the heating zones of the extruder auger is heated at a temperature between 145 °C and 280 °C for a minimum of 2 minutes so as to melt the granulate. In one embodiment, the temperature is 145 °C at this stage. In another embodiment, the temperature is 180 °C at this stage. In another embodiment, the temperature is 200 °C at this stage. In another embodiment, the temperature is 250 °C at this stage. In another embodiment, the temperature is 280 °C at this stage.

The next stage is the extrusion of fibres through a plurality of directed downwards dispersing nozzles of the extruder. In an advantageous embodiment, the diameter of each of the plurality of the dispersing nozzles used at this stage is 0.6 mm. In other embodiments, the diameter of the dispersing nozzles is 0.7 mm or 0.8 mm or 0.9 mm or 1.00 mm or 1.1 mm or 1.5 mm.

In another embodiment, nozzles of different diameters are used at this stage. In an advantageous embodiment, the diameter of some of the dispersing nozzles is 0.6 mm while the diameter of the other dispersing nozzles is larger than 0.6 mm and, for example, is 0.7 mm. In other embodiments, various combinations of two types of nozzles with diameters between 0.6 and 1.5 mm are used (e.g. 0.6 mm and 0.9 mm, 0.7 mm and 1.00 mm, 0.8 mm and 1.2 mm, 0.6 mm and 1.5 mm).

In an advantageous embodiment, silver ions are dispersed onto the surface of the newly extruded thermoplastic fibres as a mist. Coating each fibre individually with silver ions affords antibacterial properties to it and to the entire mattress evenly throughout its body rather than just the surface.

The thermoplastic fibres are then moved downwards to the outer vertical heaters situated below. The high temperature treatment of the thermoplastic fibres primarily prevents them from losing temperature on their way from the nozzle to the water. This results in the more extreme difference in temperature between the cold water and the conjugate resulting the individual filaments being more intensely curled. Furthermore, it allows the filaments to harden and, in the case of fibres coated with silver ions, to let the silver infused into the fibre structure.

Whereby, in an embodiment of the method according to the invention, the outer vertical heaters are heated up to a temperature of 150°C-285°C. In an advantageous embodiment of the method according to the invention, the outer vertical heaters are heated up to a temperature of 230-250 °C. In another advantageous embodiment, the outer vertical heaters are heated up to 230 °C.

The method according to the invention provides that after passing through the outer vertical heaters, the thermoplastic fibres are transferred to a cooling tank containing a coolant kept at 2 - 8 °C, and the fibres are loosened and formed for 45 sec. to 5min. on the moulding rollers of the cooling tank, yielding thus a conjugate of a predetermined thickness. In an advantageous embodiment of the invention, the coolant in the cooling tank is kept at 5 - 8 °C. In an advantageous embodiment, the temperature is 4 °C. In an advantageous embodiment of the invention, the said coolant is water.

The conjugate moulded to the desired thickness is then transferred to the feed rollers that hold the conjugate under the surface of the coolant, and then to the infeed-receiving belt connecting the cooling tank with the post-heating furnace.

The method according to the invention provides that the moulded conjugate passes through the postheating furnace for 45 sec to 5 minutes, where it is subjected to a temperature of 120 to 350 °C. The additional formation of the conjugate in the post-heating furnace in accordance with the method according to the invention provides improved bonding between the individual filaments of the conjugate to ensure a higher durability of the manufactured mattress material upon long-term use and provides improved fibre bonding, which reduces the level of deformation of the mattresses and improves their resilience. In an advantageous embodiment of the method according to the invention, a temperature of 200, 240 or 288 °C is applied.

In an advantageous embodiment, after passing through the post-heating furnace, the conjugate is treated with hot air at 150 °C. In another advantageous embodiment, the conjugate is treated with hot air at 200 °C. In another advantageous embodiment, the conjugate is treated with hot air at 200 °C. In another advantageous embodiment, the conjugate is treated with hot air at 290 °C. In another advantageous embodiment, the conjugate is treated with hot air at 350 °C.

After passing through the post-heating furnace, the conjugate is trimmed to a predetermined width by the edge knives of the infeed-receiving unit. Subsequently, the infeed-measuring unit with a distance sensor measures the pre-set length of the mattress layer, after which the conjugate is cut to the designated length by a cross-cutting device located downstream the infeed-receiving unit and equipped with a crosscutting knife actuator pressing the cut material. After being cut to the pre-set length, the resulting mattress layer is transferred to a receiving belt to receive the ready mattress layers.

In a further aspect, the invention comprises a device for producing a mattress layer from thermoplastic fibres, which comprises an extruder unit, a cooling tank, a post-heating furnace and an infeed-receiving unit.

In an embodiment of the invention, the infeed-receiving unit is followed by a receiving-infeed unit equipped with an infeed-measuring unit, behind which a cross-cutting device ending in a receiving belt to receive the ready material layers is located.

In an embodiment of the invention, the extruder unit comprises a raw material feed unit connected to a tripartite auger where the second leg is connected to a gearbox connected to a three-phase motor and the third leg of the tripartite auger is elongated and equipped with multiple heating zones and cooling fans. The last heating zone of the auger is connected to the extruder by a connector (e.g. an elbow).

In one version, each of the heating zones is equipped with a cooling fan. In one version, the auger contains seven heating zones, each of which is equipped with a cooling fan.

The extruder includes inside built-in heaters and ends in a plurality of manufacturing nozzles (e.g., may include 1000 nozzles) aligned vertically downwards. In one design, the extruder is equipped with nozzles, each with a diameter of 0.6 mm. In another advantageous embodiment, the extruder is equipped with nozzles, each with a diameter of 1.00 mm. However, nozzles with other diameters can also be used. In another embodiment, the extruder comprises nozzles with different diameters. In another embodiment, the extruder comprises nozzles with two diameters. In an advantageous embodiment, the extruder comprises nozzles of two diameter sizes (diameter 1 and diameter 2) where diameter 1 is 0.7 mm and diameter 2 is greater than 0.7 mm and is 1.00 mm.

Below the manufacturing nozzles of the extruder there is a cooling tank filled with coolant. In an advantageous design, the coolant may be water. According to the invention, the temperature of the coolant in the cooling tank should be kept at 2 - 8 °C. In an advantageous embodiment of the invention, the coolant in the cooling tank is kept at 5-8 °C. In an advantageous embodiment of the invention, said coolant is water and the temperature in the tank is 4 °C.

Whereby, on the housing of the cooling tank, two opposing lateral dispersing nozzles are installed to potentially disperse silver ions as a mist. Whereby, the spacing of the said dispersing nozzles is wider than the spacing of the manufacturing nozzles unit of the extruder. This arrangement allows the spray mist of silver ions to cover on both sides the fibres extruded by the manufacturing nozzles.

Below the dispersing nozzles, opposing outer vertical heaters are installed on the housing of the cooling tank to infuse silver ions into the extruded fibres and to cure the fibres coated with silver ions. Whereby, the spacing of said outer vertical heaters is wider than the spacing of the extruder manufacturing nozzles.

According to the invention, the cooling tank is provided with moulding rollers whose task is to form the extruded fibres. Below the moulding rollers there are feed rollers whose function is to keep the moulded conjugate below the surface of the coolant and to feed it to an infeed-receiving belt connecting the said cooling tank with a post-heating furnace, which is equipped with built-in heaters to cure the conjugate and fans to mix the air inside the furnace. The aforementioned post-heating furnace is equipped with cooling fans. A infeed-receiving belt runs through the entire working space of the post-heating furnace, transporting the moulded conjugate from the cooling tank to the infeed-receiving unit located downstream the post-heating furnace.

In an advantageous embodiment, the terminal hot air nozzles are located at the outlet of the furnace.

In an advantageous embodiment of the invention, the infeed-receiving unit located downstream of the post-heating furnace is equipped with pressure rollers and edge knives which cut the cured conjugate to the desired width. Whereby, owing to the pressure rollers the material is cut evenly by the edge knives. If it were not for the pressure rollers in the manufacturing process, the edge knives might translocate the material.

In an advantageous embodiment of the invention, the infeed-receiving unit is followed by a receivinginfeed unit equipped with an infeed-measuring unit, behind which a cross-cutting device ending in a receiving belt to receive the ready material layers is located.

In one embodiment, the receiving-infeed unit is equipped with an infeed-measuring unit and a distance sensor, whose task is to measure the mattress layer at an appropriate spacing to be cut to the designated length by the cross-cutting device located downstream the receiving-infeed unit and equipped with a cross-cutting knife, actuators to press the material being cut and a receiving belt to receive the ready mattress layers.

The subject-matter of the invention is depicted in the embodiment shown in the drawing wherein fig. 1 presents a diagram of the heating zones, the infeed unit and the extruder motor of the device according to the invention; fig. 2 presents a diagram of a section of the device according to the invention with particular reference to the location of the nozzles dispersing silver ions and the outer heaters placed vertically towards the outlet of the manufacturing nozzles of the extruder; fig. 3 presents, on a diagram, the juxtaposition of the extruder with the cooling tank of the device according to the invention; fig. 4 shows a diagram of the post-heating furnace of the device according to the invention; fig. 5 presents, on a diagram, the infeed-receiving unit with edge knives; fig. 6 depicts a receiving-infeed unit with an infeed-measuring unit; fig. 7 shows a cross-cutting device; fig. 8 shows a mattress according to the invention in an embodiment containing a single mattress layer made by the method according to the invention; fig. 9 depicts a mattress according to the invention in an embodiment containing two mattress layers manufactured using the method according to the invention; fig. 10 shows a mattress according to the invention in a two-layer embodiment, where each layer consists of three panels constituting mattress layers manufactured using the method according to the invention in a variant with an alternate arrangement of panels of different resilience in a single layer; fig. 11 shows a mattress according to the invention in a two-layer embodiment, where each layer consists of three panels constituting mattress layers manufactured using the method according to the invention in a variant in which the panels of the upper layer exhibit higher resilience than those of the lower layer; fig. 12 shows the results of a test using a thermal imaging camera, where A shows the view before the test, B shows the view after 60 seconds and C shows the view after 120 seconds; fig. 13a shows the results of a test using a thermal imaging camera for a mattress layer according to the Oxymesh 1 invention; fig. 13b shows the results of a test using a thermal imaging camera for the visco foam; fig. 13c shows the test results using a thermal imaging camera for the latex foam; fig. 13d shows the results of a test using a thermal imaging camera for the polyurethane foam; 14 shows a conceptual drawing of the fibre arrangement in the mattress layer of a mattress according to the invention, type Oxymesh 4.

Example 1.

The device according to the invention is shown in the drawing in which 1 denotes the three-phase motor of the extruder unit; 2 denotes the gearbox of the extruder unit; 3 denotes the raw material infeed unit; 4 denotes the auger of the extruder unit; 5 denotes the heating zones of the extruder auger; 6 denotes the coupling; 7 denotes the extruder; 8 denotes manufacturing nozzles; 9 denotes silver ions; 10 denotes dispersing nozzles; 11 denotes outer vertical heaters; 12 denotes cooling tank; 13 denotes moulding rollers; 14 denotes feed rollers; 15 denotes infeed-receiving belt; 16 denotes furnace built-in heaters; 17 denotes post-heating furnace cooling fans; 18 denotes post-heating furnace mixing fans; 19 denotes infeed-receiving unit; 20 denotes pressure rollers; 21 denotes edge knives; 22 denotes an infeedmeasuring unit; 23 denotes distance sensor; 24 denotes infeed-receiving unit with a transverse knife; 25 denotes transverse knife; 26 denotes pressure cylinders for cutting material; 27 denotes finished material receiving belt; 28 denotes hot air nozzles.

The device according to the invention is designed to produce a mattress layer from thermoplastic fibres and comprises an extruder unit, cooling tank 12, a post-heating furnace and infeed-receiving unit 19.

As shown in fig. 1, the extruder unit comprises raw material infeed unit 3, which is connected to the first leg of tripartite auger 4. The second leg of tripartite auger 4 is connected to gearbox 2 connected to three-phase motor 1. On the other hand, the third leg of the tripartite auger 4 comprises heating zones 5 equipped with cooling fans. Whereby, in this exemplary embodiment, auger 4 contains seven heating zones 5, each of which is equipped with a cooling fan.

The last heating zone 5 of auger 4 is connected by connector 6 in the form of an elbow to extruder 7 (fig. 2) with inside built-in heaters, which ends in a number of manufacturing nozzles 8 positioned vertically downwards.

In this exemplary embodiment, extruder 8 is equipped with one thousand manufacturing nozzles 8, each of which has a diameter of 0.6 mm. However, nozzles with a different diameter can be used (e.g. 0.7 mm or 0.8 mm or 0.9 mm or 1.00 mm or 1.1 mm or 1.2 mm or 1.5 mm).

Below manufacturing nozzles 8 of extruder 7 there is cooling tank 12 filled with coolant (fig. 3). The temperature of the coolant should be kept between 5 and 8 °C. In this exemplary embodiment, the coolant is water at a temperature of 5 °C.

As shown in fig. 2 and 3, two opposing lateral dispersing nozzles 10, which disperse silver ions 9 as a mist, are mounted on the housing of cooling tank 12. Whereby, the spacing of said dispersing nozzles 10 is wider than the spacing of manufacturing nozzles 8 of extruder 7. This arrangement makes it possible for the sprayed mist of silver ions 9 to cover, on both sides, the fibres extruded by the manufacturing nozzles 8.

Below dispersing nozzles 10, opposing outer vertical heaters 11 are mounted on the housing of the cooling tank 12, which infuse the silver ions 9 into the surface of the extruded fibres and cure the fibres coated with silver ions. Whereby, the spacing of the said outer vertical heaters 11 is wider than the spacing of the manufacturing nozzles 8 of the extruder 7.

As shown in fig. 3, the cooling tank 12 is provided with moulding rollers 13 whose function is to form the extruded fibres. Below the moulding rollers, there are feed rollers 14 whose function is to keep the moulded conjugate below the surface of the coolant and to feed it to infeed-receiving belt 15 connecting the said cooling tank 12 with the post-heating furnace, which is presented as a diagram in fig. 4.

As shown in fig. 4, the post-heating furnace is equipped with built-in heaters 16 to cure the conjugate and fans 18 to mix the air inside the furnace. The said post -heating furnace is equipped with cooling fans 17. On the other hand, through the entire working space of the post-heating furnace runs infeedreceiving belt 15 transporting the moulded conjugate from cooling tank 12 to infeed-receiving unit 19, located downstream the post-heating furnace. In addition, terminal hot air nozzles 28 are located at the outlet of the post-heating furnace.

As shown in fig. 5, feed-receiving unit 19 located downstream the post-heating furnace is equipped with pressure rollers 20 and edge knives 21, which cut the cured conjugate to the desired width. Whereby, pressure rollers 20 ensure that the material is cut evenly by the edge knives. If it were not for pressure rollers 20 in the production process, edge knives 21 might translocate the material. As shown in figs. 6, after the infeed-receiving unit there is a receiving-infeed unit equipped with an infeed-measuring unit 22 and a distance sensor 23, which serves to measure the correct length of the mattress layer to be cut to the designated length by the cross-cutting device (fig. 7) located downstream the receiving-infeed unit and equipped with a transverse cutter 25, actuators to press the cut material 26 and a receiving belt 27 to receive the ready mattress layers.

Example 2.

Device as in embodiment 1, except that the diameter of one half of dispersing nozzles 10 is 0.6 mm while the diameter of the remaining dispersing nozzles 10 is greater than 0.6 mm and amounts to 0.7 mm.

Example 3.

Device as in embodiment 1, except that the diameter of 30% of dispersing nozzles 10 is 0.7 mm while the diameter of the remaining dispersing nozzles 10 is greater than 0.7 mm and is 1.00 mm.

Example 4.

The device as in embodiment 1 can be used to produce a mattress layer of thermoplastic fibres.

The method for producing a thermoplastic fibre mattress layer according to the invention is a continuous process, the first step of which is the supply of the thermoplastic granulate to raw material infeed unit 3 of the extruder.

In this non-limiting exemplary embodiment, the thermoplastic material is LLDPE. Whereby, other thermoplastic materials e.g. (LLDPE, polyolefin plastomer, e.g. Affinity 1280G, Braskem PP C123- 01N, DOW™ LDPE 15OELDPE,) or combinations of thermoplastic materials can also be used as feedstock.

From the infeed unit, the granulate enters heating zones 5 of extruder auger 4, where the granulate is heated at 280°C for 2 minutes so that it is melted. After passing through heating zones 5, the melted material enters, through connector 6, extruder 7 equipped with built-in heaters and manufacturing nozzles 8 directed vertically downwards. The next stage is the extrusion of the fibres through multiple downward facing manufacturing nozzles 8 of extruder 7.

The thermoplastic fibres are then moved downwards to outer vertical heaters 11 situated below, which operate at 250 °C. The purpose of the treatment of the thermoplastic fibres is to harden them and to infuse silver into the fibre structure. Furthermore, it does not allow the fibres to lose temperature on their way from the nozzle to the water. Consequently, the more extreme difference in temperature between the cold water and the conjugate makes individual fibres more curled.

After passing through the outer heaters, the vertical thermoplastic fibres are transferred to cooling tank 12 containing water at 5 °C, where the cured fibres are loosened and formed for 45 seconds on moulding rollers 12 into a conjugate of a predetermined thickness, from which it is transferred to feed rollers 14 holding it below the surface of the coolant and then to infeed-receiving belt 15 connecting cooling tank 12 to the post-heating furnace.

Example 5.

The method as in embodiment 4, except that at the outlet of the furnace the moulded conjugate is subjected to final heating by terminal hot air nozzles 28 at 350 °C.

Example 6.

The device as in embodiment 1 can be used to produce a mattress layer of thermoplastic fibres.

The method for producing a thermoplastic fibre mattress layer according to the invention is a continuous process, the first step of which is the supply of the thermoplastic granulate to raw material infeed unit 3 of the extruder.

In this non-limiting exemplary embodiment, the thermoplastic material is LLDPE. Whereby, other thermoplastic materials e.g. (LLDPE, polyolefin plastomer, e.g. Affinity 1280G, Braskem PP C123- 01N, DOW™ LDPE 150ELDPE,) or combinations of thermoplastic materials can also be used as feedstock.

From the infeed unit, the granulate enters heating zones 5 of auger 4 of the extruder, where the granulate is heated at 280°C for 2 minutes so that it melts. After passing through heating zones 5, the melted material enters, through connector 6, extruder 7 equipped with built-in heaters and manufacturing nozzles 8 directed vertically downwards. The next stage is the extrusion of the fibres through multiple downward facing manufacturing nozzles 8 of extruder 7.

Subsequently, lateral dispersing nozzles 10 located below the mouth of manufacturing nozzles 8 disperse silver ions 9 onto the surface of the newly extruded thermoplastic fibres. In this step, each fibre is being coated with silver ions 9 so that the mattress layer acquires antibacterial properties throughout its entire body rather than only on its surface.

Thermoplastic fibres coated with silver ions 9 are then transferred downwards to outer vertical heaters

11 below, which operate at 250 °C. The treatment of the thermoplastic fibres coated with silver ions 9 allows them to harden and the silver to be infused into the fibre structure.

After passing through the outer heaters, the vertical thermoplastic fibres are transferred to cooling tank

12 containing water at 5 °C, where the cured fibres are loosened and formed for 45 seconds on moulding rollers 12 into a conjugate of a predetermined thickness, from which it is transferred to feed rollers 14 holding it below the surface of the coolant and then to infeed-receiving belt 15 connecting cooling tank 12 to the post-heating furnace.

While it passes through a post-heating furnace, the moulded conjugate is subjected to a temperature of 350 °C for 45 seconds. The additional moulding in the furnace provides improved bonding between the individual filaments of the conjugate, which ensures greater durability of the manufactured mattress material over its long-term use and provides better fibre bonding, which reduces the deformation rate of mattresses and improves their resilience.

After passing through the post-heating furnace, the conjugate is received by an infeed-receiving unit equipped with edge knives 21, which cut the conjugate to a pre-set width. On the other hand, pressure rollers 20 of the feed-receiving unit cause the conjugate to be cut evenly by the edge knives. The conjugate cut to the pre-set width is then fed to the receiving-infeed unit, where infeed-measuring unit 22 together with a distance sensor measures the pre-set length of the mattress layer. The conjugate is then cut to the designated length by a cross-cutting device (fig. 7) located downstream the receivinginfeed unit and equipped with transverse cutter 25, and actuators 26 to press the cut material. After being cut to the pre-set length, the obtained mattress layer is transferred to receiving belt 27 designated to receive the ready mattress layers.

Example 7.

Method as in embodiment 6, except that from the infeed unit the granulate goes to the heating zones 5 of the auger 4 of the extruder, where the granulate is heated at 145 °C for 5 minutes so that it melts. On the other hand, after being coated with silver ions 9, the thermoplastic fibres are subjected to a temperature of 150 °C provided by outer vertical heaters 11. The temperature of the water in cooling tank 12 is 8 °C, and the fibres are moulded for 5 minutes on moulding rollers 12 into a conjugate of a pre-set thickness. On the other hand, while passing through the post-heating furnace, the moulded conjugate is subjected to a temperature of 120 °C for 5 minutes. Then, at the outlet of the furnace, the moulded conjugate is subjected to a final heating by terminal hot air nozzles 28 at 150 °C.

Example 8.

Method as in embodiment 6, except that the thermoplastic material is Affinity 1280G polyolefin plastomer. Furthermore, the granulate from the infeed unit is transferred to heating zones 5 of extruder auger 4, where it is heated at 250 °C for 3 minutes so that it melts. On the other hand, after being coated with silver ions 9, the thermoplastic fibres are subjected to a temperature of 230 °C provided by outer vertical heaters 11. The temperature of the water in cooling tank 12 is 2 °C, and the fibres are moulded for 2 minutes on moulding rollers 12 into a conjugate of a pre-set thickness. On the other hand, while passing through the post-heating furnace, the moulded conjugate is subjected to a temperature of 200 °C for 3 minutes.

Example 9.

Method as in embodiment 6, except that after coating with silver ions 9, the thermoplastic fibres are subjected to a temperature of 240 °C provided by outer vertical heaters 11. The temperature of the water in cooling tank 12 is 5 °C, and the fibres are moulded for 3 minutes on moulding rollers 12 into a conjugate of a pre-set thickness. On the other hand, while passing through the post-heating furnace, the moulded conjugate is subjected to a temperature of 288 °C for 1 minute.

Example 10.

Method as in embodiment 6, except that after coating with silver ions 9, the thermoplastic fibres are subjected to a temperature of 230 °C provided by outer vertical heaters 11. The temperature of the water in cooling tank 12 is 4 °C, and the fibres are moulded for 1 minute on moulding rollers 12 into a conjugate of a pre-set thickness. On the other hand, while passing through the post-heating furnace, the moulded conjugate is subjected to a temperature of 240 °C for 2 minutes.

Example 11.

Method as in embodiment 6, except that after coating with silver ions 9, the thermoplastic fibres are subjected to a temperature of 285 °C provided by outer vertical heaters 11. The temperature of the water in cooling tank 12 is 8 °C, and the fibres are moulded for 5 minutes on moulding rollers 12 into a conjugate of a pre-set thickness. On the other hand, while passing through the post-heating furnace, the moulded conjugate is subjected to a temperature of 240 °C for 2 minutes. Example 12.

Method as in embodiment 6, except that after coating with silver ions 9, the thermoplastic fibres are subjected to a temperature of 230 °C provided by outer vertical heaters 11. The temperature of the water in cooling tank 12 is 5 °C, and the fibres are moulded for 4 minutes on moulding rollers 12 into a conjugate of a pre-set thickness. On the other hand, while passing through the post-heating furnace, the moulded conjugate is subjected to a temperature of 300 °C for 5 minutes.

Example 13.

The mattress layer (fig. 8) produced by the method according to the invention can be used to manufacture mattresses according to the invention for humans and for making animal beds.

In this non-limiting exemplary embodiment, the mattress layers were used to produce a double-sided mattress measuring 1.40 x 0.66 m, which is presented on a diagram in fig. 9. In this exemplary embodiment, the mattress comprises two mattress layers, each with a thickness of 6 cm and a density of 100 kg/m ³ . Whereby, each fibre of the mattress layer is coated with silver ions. In this exemplary embodiment, the mattress according to the invention has an air throughput of 90% and a resilience of 48%.

Example 14.

In this non-limiting exemplary embodiment, to produce a double-sided mattress measuring 120x200cm, a single mattress layer (fig. 8) with a thickness of 11 cm and a density of 80 kg/m ³ was used. The resilience of the resulting mattress is 55%. Whereby, each fibre of the mattress layer is coated with silver ions and the silver content of the mattress is 0.0001 % by weight of the filling of the entire mattress. Furthermore, in this non-limiting exemplary embodiment, the mattress according to the invention has an air throughput of 92%.

Example 15.

In this non- limiting exemplary embodiment, a single mattress layer with a thickness of 11 cm and a density of 120 kg/m ³ was used to manufacture a double-sided mattress measuring 120x200 cm. The resilience of the resulting mattress is 60%. Whereby, each fibre of the mattress layer is coated with silver ions. In addition, the mattress has an air throughput of 88%.

Example 16.

In this non-limiting exemplary embodiment, the mattress layers were used to produce a double-sided mattress measuring 180x200 cm, with the resilience of 60%. As indicated in fig. 10 the mattress consists of six mattress panels (i.e. six mattress layers made by the method according to the invention) arranged in two layers with a total thickness of 25 cm and a density of 120 kg/m ³ . Whereby, in this exemplary embodiment, the middle panel of the upper layer has an increased density relative to the other panels of the upper layer. This is for the sake of a lesser sinking of the lumbar section and an increased comfort for some people. Whereby, each fibre of each panel (i.e. the mattress layers made by the method according to the invention) is coated with silver ions. Furthermore, in this exemplary embodiment, the mattress has an air throughput of 85%.

Example 17.

In this non-limiting exemplary embodiment, the mattress layers were used to produce a double-sided mattress measuring 180x200 cm with its resilience of 60% In this exemplary embodiment, the mattress contains three mattress layers with a total thickness of 25 cm and a density of 120 kg/m ³ (two layers each 10 cm thick and one having a thickness of 5 cm). The mattress consists of three layers stacked on top of each other. Whereby, each fibre of the mattress layer is coated with silver ions. The silver content of the mattress represents 0.00005 % by weight of the filling of the entire mattress. Furthermore, in this exemplary embodiment, the mattress according to the invention has an air permeability of 82%.

Example 18.

In this non-limiting exemplary embodiment, the mattress layer produced by the method according to the invention was used to produce a double-sided mattress measuring 120x60cm with a resilience of 50%. The mattress was created from a single mattress layer with a thickness of 11cm. Whereby, each fibre of the mattress layer is coated with silver ions. However, the silver content of the mattress represents 0.0001 % by weight of the filling of the entire mattress.

Example 19.

In this non-limiting exemplary embodiment, the mattress layer produced by the method according to the invention was used to produce a double-sided mattress with a modular structure. As shown in figs. 11 the mattress according to the invention is a two-layer mattress made of a total of six panels arranged in two mattress layers made by the method according to the invention in a variant in which the panels of the upper layer show higher resilience than the panels of the lower layer. The dimensions of the mattress are 120x60cm.

The use of the panel variant of the mattress according to the invention may facilitate transport of the mattress and in a modular way choose which density of the mattress is best for which part of the body. This provides the customer with the possibility to select the modules as desired.

Example 20. In this non-limiting exemplary embodiment, the physical properties of a mattress according to the invention containing a single mattress layer manufactured by the method according to the invention were tested, samples of which are denoted as:

• Oxymesh 1 - A mattress according to the invention containing a variant 1 of the mattress layer;

• Oxymesh 2 - A mattress according to the invention containing variant 2 of the mattress layer;

• Oxymesh 3 - A mattress according to the invention containing variant 3 of the mattress layer;

• Oxymesh 4 - A mattress according to the invention containing variant 4 of the mattress layer;

• Oxymesh 5 - A mattress according to the invention containing variant 5 of the mattress layer.

Whereby, Oxymesh 1 was made using the method according to embodiment 4, except that the fibres in the zone of the outer heaters 11 are heated at 250°C, the temperature in the cooling tank was 4°C, the conjugate spent 2 minutes and 15 seconds in the heating furnace at 273°C. The mattress had a size of 50x50x10 cm and a material density of 70 kg/m ³ .

Oxymesh 2 was made using the method according to embodiment 4, except that the fibres in the zone of the outer heaters 11 were heated at 255°C, the temperature in the cooling tank was 4°C, the conjugate spent 1 minute and 22 seconds in the heating furnace at 24O°C. The mattress had a size of 50x50x10 cm and a material density of 35 kg/m ³ .

Oxymesh 3 was made by the method according to embodiment 4, except that the fibres were heated in the zone of the outer heaters 11 at 250C °C, the temperature in the cooling tank was 4C °C, the conjugate spent 2 minutes and 44 seconds in the heating furnace at 270°C. The mattress was characterised by a size of 50x50x10 cm and a material density of 120 kg/m ³ .

Oxymesh 4 was made similarly to embodiment 4, except that the fibres in the zone of the outer heaters 11 were heated at 250°C, the temperature in the cooling tank was 4°C, the conjugate spent 2 minutes and 15 seconds in the heating furnace at 273°C. The mattress was characterised by a size of 50x50x10 cm and a material density of 70 kg/m ³ . Whereby, at the stage of extrusion of the fibres through multiple manufacturing nozzles, a 2-level extrusion was used, i.e. nozzles with different diameters were used, where some nozzles have a larger diameter (diameter = 1.00 mm) than other nozzles (diameter = 0.7 mm). Over the width of the mattress, a 5 cm thick mattress layer has fibres with a diameter of 0.7 mm and the remaining 5 cm has fibres with a diameter of 1.0mm. Because the fibres connect with each other when in contact with water, then between 4 and 6 cm of the cross-sectional thickness of the mattress, some of the fibres are thicker and some are thinner (as shown in fig. 13).

Oxymesh 5 was made as in embodiment 4, except that the fibres were heated in the zone of the outer heaters 11 at 250°C, the temperature in the cooling tank was 4°C, the conjugate spent 2 minutes and 15 seconds in the heating furnace at 250°C, where at the outlet of the heating furnace terminal hot air nozzles 28 blew air at 250°C into the mattress layer. The mattress was characterised by a size of 50x50x10 cm and a material density of 70 kg/m ³ .

The mattresses according to the invention were compared with mattresses of analogous dimensions (i.e. 50x50x10 cm) made of typical known materials available on the market, such as visco foam, Latex or polyurethane foam.

1. Bounce-back test

The resilience analysis was carried out using the elasticity (rebound) test, which involved dropping a steel ball on the tested piece. The load ball had a weight of 3kg. The rebound height was then measured to express as a percentage of height drop. The ball was dropped from a height of 1.1m. A camera was set up nearby to record the fall and rebound of the ball. The camera's perpendicular distance from the meter was 96 cm. The distance from the ground to the camera was 64 cm and 11 cm for the camera in the second alignment 'from below'. All mattress samples tested were 10 cm thick. The experiment was repeated several times.

The following mattress samples were tested:

• Oxymesh 1

• Oxymesh 2

• Oxymesh 3

• Oxymesh 4

• Oxymesh 5

• Visco foam

• Latex

• polyurethane foam

The results obtained are shown in Table 1 below.

Table 1. Bounce-back test results

The analysis demonstrated that the mattress layers of the mattress according to the invention showed a significantly higher resilience compared to mattresses known from the state of the art.

2. Absorption of liquids inside the mattress structure

The following mattress samples were tested:

• Oxymesh 1

• Oxymesh 2

• Oxymesh 3

• Oxymesh 4

• Oxymesh 5

• Visco foam

• Latex

• polyurethane foam

The test of absorption of liquid inside the mattress structure was conducted as follows: the mattress pieces (samples) were weighed dry, as shown in Table 2 below.

Table 2. Weights for individual dry mattress pieces

Two sub-analyses A and B were then carried out.

Analysis A:

The mattress samples were placed on a flat watertable for 10 minutes to absorb water into their structure. They were then raised above the watertable for 60 seconds to let the water out and were weighed. The results are shown in Table 3 below:

Table 3. Weight of wet mattress samples after 10 minutes in water

Analysis B:

In this analysis, the mattresses were 'forcibly' submerged under water in such a way as to absorb water into their structure. The time of being submerged in water was 10 minutes. The mattresses were then raised in the air for 60 seconds, to let the water out. The mattresses were then weighed and the results are shown in Table 4 below:

Table 4. Weight of wet mattress samples analysed in analysis B:

Analysis A shows what happens to a mattress if it is placed on a flat watertable. Mattresses according to the invention immediately sunk in water (the density of the threads is greater than that of water, and therefore water immediately displaced air from the space between the threads of the mattress. Therefore, the mattress sunk immediately while achieving "full water absorption." The foam mattresses known from the state of the art (latex, visco foam, polyurethane foam) have a different structure and if the mattresses are not "forcefully" submerged under water (as indicated in analysis B), they very slowly absorb water.

3. Drying of the mattress

The drying performance of the mattress was measured in a room with a humidity level of 40%. The room temperature was 24.1 °C. The floor temperature was 26.3 °C.

The following mattress samples were tested:

• Oxymesh 1

• Oxymesh 2 • Oxymesh 3

• Oxymesh 4

• Oxymesh 5

• Visco foam

• Latex

• polyurethane foam

The dry mattress pieces were weighed and then immersed in water for 10 minutes, analogous to test 2 analysis B. Water was drained from the mattress pieces (samples) by squeezing and whisking them for 10 seconds and were exposed to dry. Whereby, the aforementioned whisking was intended to simulate the “normal” matress drying process. The analysed mattress samples were then allowed to dry freely and weighed after Ih, after 2h, after 6h, after 18h and after 24h. The results are presented in Tables 5 and 6 below:

Table 5. Drying process of the tested mattresses - weight comparison

Table 6. Drying process of the tested mattresses - a percentage comparison |

The analysis showed that the mattresses according to the invention had already dried to at least 80 per cent after 1 hour (depending on the sample, an 80-100 per cent drying rate was achieved) after the mattress had been shaken out for 10 seconds beforehand. Furthermore, the mattresses according to the invention dried completely after maximum 24 hours (depending on the sample, 100% drying was achieved in 2-24h), whereas the other materials dried very slowly and remained significantly wet by the end of the experiment.

The pace of drying of the mattresses according to the invention is another fundamental advantage over existing solutions, as it allows for a fundamental reduction in the cleaning cycle of the mattresses and shortens their reuse time after cleaning.

4. Test using a thermal imaging camera

The determination of the heat transfer coefficient consisted of blowing warm air from below at a distance of 25 cm on a piece of mattress structure. The temperature of the mattress and the temperature distribution for the different mattress materials were examined before the test, after 60 seconds and after 120 seconds using an HTI HT-18 thermal imaging camera. The room temperature was 11 °C+/-1.0°C.

The following mattress samples were tested:

• Oxymesh 1

• Visco foam

• Latex

• polyurethane foam

The results obtained are shown in fig. 12, where A shows the view before the start of the test, B shows the view after 60 seconds and C shows the view after 120 seconds. As shown in fig. 12 the temperature moves through the structure of the mattress according to the invention, the heat transfer coefficient after 60 sec. was 35% to increase to 65% after 120 sec. In contrast, the other mattresses reflected heat.

Furthermore, the test showed the air throughput of the mattress according to the invention and the exchange of warm air for cold air. While such results were not obtained with mattresses known from the state of the art.

5. Water throughput test

The following mattress samples were tested:

• Oxymesh 1

• Oxymesh 2

• Oxymesh 3 • Oxymesh 4

• Oxymesh 5

• Visco foam

• Latex

• polyurethane foam

The water throughput test was conducted for different mattress materials. A piece of the test mattress material was placed over a container of water in such a way that the water could only seep through the material, while it was impossible to pour water that 'bounced' off the mattress back into the container. Slowly, 1,000 grams of water were poured and 10 minutes were allowed to examine the results. The test was repeated 10 times. The results are shown in Table 7 below:

Table 7. Water throughput test results

The analysis showed that the mattresses according to the invention were characterised by a high throughput, which is another fundamental advantage over existing solutions, as it allows them to be thoroughly cleaned of dirt such as urine or sweat.

6. Air velocity reduction test

The degree of air passage through the following samples was investigated:

• Oxymesh 1

• Oxymesh 2

• Oxymesh 3

• Oxymesh 4

• Oxymesh 5

• Visco foam

• Latex

• polyurethane foam An air pump was used to pump air at a constant speed. The air speed at the tested altitude was 18.72 km/h on average. The speed was measured using a Habotest HT625B digital wind speed meter anemometer. The test was repeated several times. The results are shown in Table 8.

Table 8. Analysis of the air throughput of the tested mattresses

7. Temperature drop test

All samples were heated in a heating furnace for a minimum of 60 minutes at 60°C. An electronic thermometer with a probe was used for the test, where the probe (thermometer) was inserted into the centre of the sample to a depth of 6 cm inside the mattress sample and halfway through the thickness of the sample, i.e. 5 cm.

As can be seen in the table below, the mattress layer according to the invention - Oxymesh 1 - exhaled the temperature much faster throughout the volume. The room temperature during the tests was 21.0+/- 1.0°C.

Table 9. Temperature drop test in degrees Celsius.

While a thermometer measured the temperature inside the structure, a thermal imaging camera was used to observe the temperature changes that were taking place outside. The mattress loses temperature throughout the volume, not just from the inside. The results obtained are shown in fig. 13a - 13d. While using the thermal imaging camera it was noted that the Oxymesh 1 structure exhaled temperature differently to the foams tested according to Table 9. The temperature decreased throughout the volume of the mattress, and most rapidly from the bottom. For visco, latex and polyurethane foams, the exhalation of the temperature occurred in the direction from the corners to the centre of the tested mattress layer.

In this way, the heat loss rate of the mattress according to the invention was determined to be at least 30% within 10 minutes, advantageously 50 per cent.