Honeycomb Structure

The instant invention relates to a water drainage and water retention body according to the subject matter of independent claim 1 as well as to a method for producing the water drainage and water retention body according to independent claim 15.

State of the Art

Water drainage and water retention bodies for regulating a soil moisture of outdoor areas, for examples of squares and grassed areas, are already known. It is increasingly important that rain water can drain to a sufficient extent on these areas, so as to avoid flooding, but, on the other hand, that rain water can also be saved, so as to maintain soil moisture, if necessary.

The invention is thus in particular based on the object of providing for an improved water drainage and water retention body for regulating the soil moisture, which encompasses a high mechanical stability and a high water storage capacity and which can thereby be produced and installed in a simple manner.

To solve these two opposite problems, different solutions are known, which are either based on roll goods (e.g. dimpled film), which can be installed in webs, or on blocks (e.g. extruded honeycomb blocks or injection molded blocks), which cannot be installed in webs. In the case of the design of a rain water management system made of blocks, the positioning and connecting of the blocks is time-consuming. A large installation depth and thus a lot of digging is furthermore required. In particular the high water storage capacity and the high burst strength, which provides for a versatile use of the area, is advantageous in the case of systems consisting of honeycomb blocks.

The patent publications WO 88/02422 and FR 2659996 (Induplast) show the use of honeycomb blocks. The patent publication DE 10 2005 056131 (Heitker) and DE 20 2005 002169 (Rehau) show the use of injection molded plastic blocks. Rain water management systems of roll goods, such as dimpled webs (e.g.

Delta®- Floraxx by Dorken or Floradrain® by ZinCo) can be installed across large areas in a quick and cost-efficient manner, but have a relatively low water

storage capacity and a low burst strength, which limits the use of the area.

Disclosure of the Invention

The subject matter of the instant invention is a water drainage and water retention body for use in subsoil areas, in particular in the outdoor area, comprising a plurality of substantially prismatic hollow bodies, which adjoin one another in a horizontal plane in the use state, which in each case encompass a bottom area, which is arranged substantially parallel to the horizontal plane, and a jacket area unit, and the axes of which are arranged substantially in a vertical direction perpendicular to the horizontal plane, wherein at least one jacket area of the jacket area unit of a hollow body simultaneously serves as a jacket area of the jacket area unit of an adjoining hollow body. In this context, a "prismatic" body is to be understood in particular to be a body, which encompasses a base area, which is formed by a polygon, and the side edges of which, which form edges of jacket areas of the prismatic body, run parallel, and have the same length. In this context, "substantially prismatic" is to be understood in particular such that a deviation of a volume, which is delimited by the hollow body, of a prismatic body, which is adapted optimally to the hollow body according to the method of least squares, is advantageously less than 30%, preferably less than 20% and, more preferably, less than 10% of the volume, which is delimited by the hollow body. In context with directions, with parallelism and with inclines of planes, "substantially" is to be understood in particular in this application such that an angular deviation from the identified direction, parallelism or plane incline is advantageously less than 20%, preferably less than 15% and, more preferably, less than 10%. In response to a suitable embodiment, a water drainage and water retention body comprising good possibilities for regulating rain or irrigation water can thus be provided by means of water drainage and/or a retention of water. The water drainage and water retention body according to the invention can encompass a high capability to absorb water in a compact arrangement with a low consumption of materials for its production. In addition, a high stability against external force effects in the vertical direction and against transverse stresses in horizontal direction can be attained at the same time, for example by means of a braking motor vehicle.

In an advantageous embodiment, an edge line, which delimits the bottom area of a first hollow body of the hollow bodies simultaneously forms a part of an edge line of one of the jacket areas of the jacket area unit of at least one of the hollow bodies adjoining the first hollow body. Spatially close, alternating possibilities of water retention and water drainage can thus be provided in a simple and compact manner.

In the event that one of the jacket areas of the jacket area unit of at least one hollow body of the hollow bodies and one of the jacket areas of the jacket area unit of one of the hollow bodies adjoining the hollow body are connected to one another by means of material engagement, a simple, cost-efficient producibility of the water drainage and water retention body can be attained.

It is furthermore proposed for at least one of the jacket areas of the jacket area unit of at least one hollow body of the hollow bodies and for one of the jacket areas of the jacket area unit of one of the hollow bodies adjoining the hollow body to be embodied separately, and to at least partially be in direct contact to one another in the use state. In response to a suitable embodiment according to a production of the water drainage and water retention body, a form, which can be rolled up onto a roll and an

arrangement, which is compact in the use state, can be attained through this.

In a further advantageous embodiment, the bottom areas of the hollow bodies in a first direction, which is arranged parallel to the horizontal plane, form a closed, connected area, which is arranged substantially parallel to the horizontal plane, whereby a simple division of the subsoil area into first partial areas, for which a water retention is provided, and into second partial areas, for which a water drainage is provided, can be attained.

In addition, it is proposed for the bottom areas of the hollow bodies not to embody a connected area in at least a second direction, which is arranged parallel to the horizontal plane and which intersects the first direction in one point. An even division of the subsoil area into partial areas with water retention and into partial areas with water drainage can be attained through this in a structurally simple manner.

Advantageously, the bottom areas of a first hollow body of the hollow bodies and the bottom area of at least one of the hollow bodies adjoining the first hollow body are embodied so as to be spaced apart in the vertical direction. For a division of the subsoil area into partial areas, for which a water retention is provided, and into partial areas, for which a water drainage is provided, many different alternative possibilities can thus be provided. The water drainage and water retention body can furthermore be equipped with a large water retention volume through this. Preferably, a distance between the bottom area of one of the hollow bodies and the bottom area of one of the adjoining hollow bodies in the vertical direction is between 10 mm and 500 mm.

Particularly preferably, it is 20 mm or 100 mm.

In a further advantageous embodiment, the bottom areas are adjoining hollow bodies, which are arranged along at least a second direction, which is arranged parallel to the horizontal plane and which intersects the first direction in one point, so as to be spaced apart in the vertical direction, whereby an even division of the subsoil area into partial areas, for which a water retention is provided, and into partial areas, for which a water drainage is provided, are attained in a structurally simple manner.

It is furthermore proposed for the bottom area of at least one of the hollow bodies to comprise at least one recess, which is embodied as aperture in vertical

direction. Further alternative possibilities in view of the water retention and of the water drainage and for an adaptation of the water drainage and water retention body to a local subsoil characteristic can thus be provided to attain a desired water distribution. For example, provision can be made for a plurality of

apertures, which are formed by small holes, and which can be attached to the bottom areas by means of a needle roller in a cost-efficient manner. In the event that the small holes are provided at bottom areas of the hollow bodies close to the surface, air can escape into the hollow body when water enters from below.

The water discharge from the hollow bodies can be adjusted by means of small holes, which are provided on bottom areas, which are located far away from the surface. The size of the holes thereby determines a flow rate of the water in and out of the hollow bodies.

In a particularly advantageous manner, the bottom areas of the hollow bodies are embodied substantially in the shape of regular hexagons. On the one hand, the subsoil area can thus be covered with hollow bodies with as few gaps as possible and, on the other hand, areas of the water drainage and water retention body, which are neither provided for retaining water nor for draining water, can be kept as small as possible. In the vertical direction, a high stability can be attained in a structurally simple manner and in using little material. Advantageously, the hollow bodies can be arranged in particular in the shape of a honeycomb structure. When the bottom areas of the hollow bodies in each case encompass exactly two axes of symmetry, solutions with more variable design possibilities can be

provided than in the case of a solution comprising a higher symmetry, while maintaining the simple structure and the high stability. For example, the bottom areas of the hollow bodies can encompass a shape of a hexagon comprising exactly two axes of symmetry, which are perpendicular to one another, and two different side lengths.

In an advantageous embodiment, the hollow bodies consist substantially of a thermoplastic plastic. In this context, "substantially" is to be understood in particular such that the hollow bodies consist of the thermoplastic plastic by a portion of at least 40% by vol., preferably of at least 70% by vol., and, more preferably, of at least 90% by vol. The hollow bodies can in particular also consist completely of the thermoplastic plastic. In the alternative, the hollow bodies can also consist of the thermoplastic plastic with 10%-50% of talcum as filler or of other cost-efficient fillers. By means of this embodiment, the water drainage and water retention bodies can be produced in a cost-efficient, large-scale process, for example by means of a rotary vacuum deep-drawing process. Preferably, the water drainage and water retention bodies are produced from extruded polypropylene (PP) with 20% of talcum as filler.

Advantageously, the hollow bodies of the water drainage and water retention body are arranged without gaps in an elongated web in the use state. A simple handling and a good installability can thereby be attained in response to covering an area as completely as possible.

In addition, a water drainage and water retention system comprising at least one of the embodied and further developed water drainage and water retention bodies and at least one carded web unit, which is connected to at least two bottom areas of two of the hollow bodies of the water drainage and water retention body by means of material engagement. The water drainage and water retention body can thus be equipped with a cover layer, so as to avoid an undesired penetration of material or so as to prevent material from being washed out of the hollow bodies. The carded web unit can also be embodied as a water- impermeable film, whereby further design possibilities can be provided for regulating a moisture of the subsoil area. In this case, the carded web unit can advantageously be provided on a side of the water drainage and water retention bodies, which faces away from the surface. On principle, the water drainage and water retention system can in each case also encompass a carded web unit on the side of the water drainage and water retention bodies, which faces the surface, as well as on the side of the water drainage and water retention bodies, which faces away from the surface. Drawings

Further advantages follow form the following description of the drawings.

Exemplary embodiments of the invention are illustrated in the drawing. The

drawing, the description and the claims contain numerous features in

combination. The person of skill in the art will advantageously also consider the features individually and will combine them to form meaningful further

combinations.

As shown:

Fig. 1 shows a schematic illustration of a water drainage and water retention

system according to the invention in a use state in a subsoil area in a lateral view,

Fig. 2a shows the water drainage and water retention system according to Fig. 1 comprising a water drainage and water retention body in different stages of a production in a view at an angle from above,

Fig. 2b shows the water drainage and water retention system according to Fig.

2a in a view at an angle from below,

Fig. 3 shows an increased detail view of the water drainage and water

retention body according to Fig. 1 ,

Fig. 4 shows the water drainage and water retention system according to Fig. 1 in a rolled up state, and

Fig. 5 shows an alternative form of a bottom area of hollow bodies of the water drainage and water retention body according to Fig. 1 in a top view.

Description of the Exemplary Embodiments

Fig. 1 shows a schematic illustration of a water drainage and water retention system 10 according to the invention in a use state in a subsoil area 12, which is embodied as a garage entrance comprising a lawn covering as surface 14. The subsoil area 12 extends substantially parallel to a horizontal plane 16.

In a view at an angle from the top, Fig. 2a shows the water drainage and water retention system 10 according to Fig. 1 with a water drainage and water retention body according to the invention for use in the subsoil area 12 of an outdoor area, for example of a square, a grassed area or of a flat roof, which is embodied as inverted roof, comprising surfaces of lawn, artificial lawn, sand, gravel or rocks, in different stages of a production. The water drainage and water retention system 10 is provided for allowing rain water and/or irrigation water to drain to a sufficient extent on the one hand, so as to avoid the formation of puddles and flooding of the subsoil area 12 and, on the other hand, to retain rain water and/or irrigation water to a sufficient extent, so as to supply a plant cover of the subsoil area 12 with moisture.

The water drainage and water retention body consists completely of a thermoplastic plastic, which is formed of extruded polypropylene (PP) and encompasses a plurality of substantially prismatic hollow bodies 20, 22, 24, which adjoin one another in the horizontal plane 16 in a use state, in which the water drainage and water retention body is integrated in the subsoil area 12 and is covered with the surface 14 of lawn, artificial lawn, sand, gravel or rocks. In the use state, said hollow bodies are arranged in an elongated web 44 comprising a web extension direction 46, wherein edge areas 48 of the web 44 encompass partial bodies of prismatic hollow bodies 20, 22, 24.

Each of the prismatic hollow bodies 20, 22, 24 comprises a bottom area 26, which, with the exception of edge roundings in the shape of a regular hexagon, is embodied such that, in the use state, a complete covering of the subsoil area 12 with hollow bodies 20, 22, 24 is made possible on principle. The bottom area 26 of each of the hollow bodies 20, 22, 24 is arranged parallel to the horizontal plane 16.

The set-up of the adjoining hollow bodies 20, 22, 24 will be described below based on a first hollow body 20 of the plurality of hollow bodies 20, 22, 24 (Fig. 2a). Each of the prismatic hollow bodies 20, 22, 24 encompasses a jacket area unit 28 comprising six jacket areas 30 and one axis 32 (Fig. 3), which, in the use state, is arranged in a vertical direction 18 perpendicular to the horizontal plane 16. As can be seen from Fig. 3, four of the six jacket areas 30 of the jacket area unit 28 of the first hollow body 20 simultaneously serves as a jacket area 30 of the jacket area unit 30 of one of four hollow bodies 22 adjoining the first hollow body 20.

The bottom area 26 of the hollow bodies 20, 22, 24 are arranged in the vertical direction 18 in two different levels. When observing the first hollow body 20, to which six further hollow bodies 22, 24 adjoin, it can be seen that the bottom area 26 of the first hollow body 20 and the bottom area 26 of four hollow bodies 22 of the six adjoining hollow bodies 22, 24 are embodied so as to be spaced apart in the vertical direction 18, wherein the bottom area 26 of the first hollow body 20 is arranged so as to face the surface 14 and the bottom areas 26 of the four adjoining hollow bodies 22 are arranged so as to face away from the surface 14 and a distance of the bottom areas 26 in the vertical direction 18 is 30 mm. The four adjoining hollow bodies 22 are thus equipped for a retention of rain or irrigation water, while the first hollow body 20 is provided for being filled from below with excess water quantities. The bottom area 26 of the first hollow body 20 comprises a plurality of recesses, which are embodied as aperture 38 in the vertical direction 18, which allow for an exchange of water in the vertical direction 18 and in the opposite direction thereof, and which make it possible to provide for an intermediate stage between a hollow body 20, 22, 24, which is provided for water retention, and a hollow body 20, 22, 24, which is provided for water drainage. Further ones of the hollow bodies 20, 22, 24 are also equipped with apertures 38. This, however, is not illustrated for the sake of clarity.

By embodying the bottom areas 26 of the hollow bodies 20, 22, 24 as regular hexagons and the integration into the subsoil area 12, the water drainage and water retention body encompasses a high stability as compared to an external application of force 50 in the vertical direction 18 and as compared to a transverse strain 52 in a direction, which is arranged parallel to the horizontal plane 16, as they are created by means of a motor vehicle, for example, which brakes on the subsoil area 12, which is equipped with the water drainage and water retention body (Fig. 1 ).

In addition, it is obvious from Fig. 3 that an edge line 34, which delimits the bottom area 26 of the first hollow body 20, simultaneously forms a part of an edge line 36 of one of the jacket areas 30 of the jacket area unit 28 of four hollow bodies 22 of the six adjoining hollow bodies 22, 24.

In a first direction 40, which is arranged parallel to the horizontal plane 16, the bottom area 26 of the first hollow body 20 with bottom areas 26 of the two

remaining hollow bodies 24 of the six adjoining hollow bodies 24, 26, forms a closed connected area, which is arranged parallel to the horizontal plane 16. For the hollow bodies 24, which are arranged in the first direction 40, this continues such that, as can be seen from Fig. 2a, strip-shaped partial areas of the subsoil area 12, which are provided for water retention, alternate with strip-shaped partial surfaces of the subsoil area 12, which are provided for water drainage, in a

direction, which is arranged perpendicular to the first direction 40 and parallel to the horizontal plane 16. A carded web unit 54, which is formed by a water- permeable non-woven polyester fabric, is connected to the bottom areas 26 of the hollow bodies 20, 24, which are provided for a water drainage, by means of a laminating process by means of material engagement. The carded web unit 54 improves a coherence of the water drainage and water retention body and

prevents an undesired permeation of material into the hollow bodies 20, 22, 24, which are provided for water retention.

In a second direction 42 - and in further directions parallel to the second direction - which are arranged parallel to the horizontal plane 16, intersecting the first direction 40 in a point and along which the first hollow body 20 is arranged, the bottom area 26 of the first hollow body 20 does not form a connected area with bottom areas 26 of hollow bodies 22, which adjoin the first hollow body 20 in the second direction 42. The bottom areas 26 of the adjoining hollow bodies 22, which are arranged along the second direction 42, are embodied so as to be spaced apart so that, on the subsoil areas 12 at a close distance, partial areas of the subsoil area 12, which are provided for water retention, alternate with partial areas of the subsoil area 12, which are provided for water drainage, whereby a highly even water distribution can be made possible.

The respective left part of Figures 2a and 2b shows the water drainage and water retention body in a state of the production after the use of a non-illustrated rotary vacuum deep-drawing process onto an extruded PP film web 56. In this state, the PP film web 56 encompasses a folding line 58, which runs at right angles to the web extension direction 46. Rectangular-shaped partial areas 60, 62 of the molded PP film web 56, which are provided as jacket areas 30 of hollow bodies 20, 24 on both sides of the folding line 56 and which are oriented in the web extension direction 46, the shorter rectangle side thereof, which faces the folding line 58, is aligned with the folding line 58. In a further production step, the rectangular-shaped partial areas 60, 62, which are arranged on both sides of the folding line 58, are placed against one another and are fused thermally, so that a jacket area 30 of the jacket area units 28 of the hollow bodies 20, 24 and a jacket area 28 of the jacket area unit of one of the adjoining hollow bodies 20, 24 are connected to one another by means of material engagement. The hollow bodies 20, 24, the jacket areas 28 of which are fused thermally, encompass bottom areas 26, which face the surface 14.

It can be seen from the right-hand part of Fig. 2b and from the detailed view in Fig. 3 that two hollow bodies 22, which are arranged so as to adjoin one another in the first direction 40 and the bottom areas 26 of which face away from the surface 14 in the use state, in each case encompass a separately embodied jacket area 64, 66 of the jacket area unit 28, which, in the use state, in which the axes 32 of the hollow bodies 20, 22, 24 are oriented in the vertical direction 18, are partially in a direct contact with one another. The separate embodiment of these jacket areas 30 makes it possible to space apart the hollow bodies 20, 22, 24 on one side of the web 44, which, in the use state, faces away from the surface 14, whereby the water drainage and water retention system can be wound up as a roll with or without roll core (Fig. 4) and nonetheless encompasses a compact arrangement in the use state. On principle, the water drainage and water retention system 10 can be wound continuously as a roll during the production and can be unrolled from the roll shape for being installed as web 44. Instead of the shape of a regular hexagon comprising six axes of symmetry, bottom areas 78 of alternatively embodied hollow bodies 76 can be embodied in the shape of a polygon comprising exactly two axes of symmetry 68, 70. Fig. 5 shows the alternative embodiment of the bottom areas 78 of the hollow bodies 76 in the shape of a hexagon comprising exactly two axes of symmetry 68, 70, which are perpendicular to one another, and comprising two different side lengths 72, 74. The production of such hollow bodies 76 requires a slightly increased material usage, based on the covered subsoil area 12. However, as in the case of the regular hexagon, the subsoil area 12 can also be covered without gaps, wherein further design possibilities for a layout of the water drainage and water retention body are provided by varying the side lengths 72, 74.

List of Reference Numerals 0 water drainage and water side length retention system

2 subsoil area hollow body 4 surface bottom area 6 horizontal plane

8 vertical direction

0 hollow body (first)

2 hollow body (open on the top)

4 hollow body (closed on the top)

6 bottom area

8 jacket area unit

0 jacket area

2 axis

4 edge line

6 edge line

8 aperture

0 first direction

2 second direction

4 web

6 web extension direction

8 edge area (of the web)

0 force

2 transverse strain

4 carded web unit

6 PP film web

8 folding line

0 rectangular-shaped partial area

2 rectangular-shaped partial area

4 separate jacket area

6 separate jacket area

8 axis of symmetry

0 axis of symmetry

72 side length