SHOCK-ABSORBING LAYER AS WELL AS METHOD FOR ITS MANUFACTURING

Abstract

 Shock-absorbing layer (1) comprising a backing cloth (2) having a top surface (3), a bottom surface (4), and a plurality of loops (6). In particular, the loops are formed from fibers substantially made of at least one elastic polymer (5), which are attached to the backing cloth according to a loop-pile principle, with the number of loops per unit of area being at least 80,000 loops per m² and at most 160,000 loops per m². A method for manufacturing a shock-absorbing layer is also disclosed.

Description

TECHNICAL FlELD

[0001] In a first aspect, the invention relates to a shock-absorbing layer.

[0002] In a second aspect, the invention relates to a method for manufacturing a shock-absorbing layer.

PRIOR ART

[0003] In general, shock-absorbing layers have an important function in situations involving impact or vibration. Among other things, shock-absorbing layers have an important role in reducing the risk of injuries in athletes. When athletes play on a hard surface, the impact of their movements can be damaging to their muscles, joints and bones, and can significantly increase the risk of injury.

[0004] In the context of sports, the use of a shock-absorbing layer in an artificial turf installation is a well-known example. The shock-absorbing layer in an artificial turf installation is often a layer of cushioning material that is installed under artificial turf to provide additional shock absorption and cushioning. This layer of material is usually made of foam, rubber, or other synthetic materials, and is designed to help prevent injuries that may occur from falls or impacts on the artificial turf field. A stabilizing layer is placed on top of this shock-absorbing layer, followed by a layer of artificial turf with a cut pile. The tufting of artificial turf is a well-known and frequently used technique in the production of artificial turf fields. With this technique, the artificial turf is interwoven with a textile backing. There are several methods of tufting, including the so-called cut-pile process. With this technique, the fibers are cut, resulting in a smooth surface that provides a soft, comfortable surface.

[0005] EP 3 505 680 describes an artificial turf installation consisting of, inter alia, a shock-absorbing layer built up from random three-dimensional loop material.

[0006] EP 2 771 513 describes a shock-absorbing layer consisting of a three-dimensional entangled mat of extruded fibers made of a thermoplastic elastomeric polymer, in particular a thermoplastic elastomeric polyester polymer or a thermoplastic elastomeric polyurethane polymer.

[0007] EP 3 885 400 describes a shock-absorbing layer for artificial turf installations, wherein the shock-absorbing layer consists of low density expanded polyethylene (EPE).

[0008] EP 3 354 794 describes a support layer for supporting an artificial turf installation, in which the support layer is made of a polymer foam, preferably with a density between 20 and 70 grams per liter, such as a polyolefin foam.

[0009] EP 3 126 573 describes a mat for forming an artificial turf installation consisting of a cushioning layer; and artificial fibers; the aforementioned artificial fibers are attached to the aforementioned cushioning layer using tufting techniques.

[0010] It can be difficult to find a suitable shock-absorbing layer for certain sports facilities, because not all materials and technologies are suitable for all sports and surfaces. For example, a shock-absorbing layer that is suitable for artificial turf cannot necessarily be used as a judo mat or other surfaces. In addition, there are several factors to consider when choosing the right shock-absorbing layer, such as the intensity of the sports activity, the characteristics of the surface, and the requirements of the sports associations. Due to this, searching for a suitable shock-absorbing layer can be a complex and challenging process.

[0011] Although artificial turf installations with known shock-absorbing layers already offer advantages over natural grass fields, the overall shock absorption and energy restitution properties still have room for improvement. Moreover, known shock-absorbing layers have disadvantages due to a limited ability to drain liquids, such as water, from the artificial turf installation.

[0012] Accordingly, there is a need for an improved shock-absorbing layer that can be applied on a large scale in various devices, with improved shock absorption properties.

[0013] The present invention aims to resolve at least some of the problems and disadvantages mentioned above.

SUMMARY OF THE INVENTION

[0014] In a first aspect, the invention relates to a shock-absorbing layer according to claim 1. Preferred embodiments of the first aspect of the invention are described in claims 2 to 11.

[0015] The invention relates to a shock-absorbing layer consisting of a backing cloth with a top surface, a bottom surface and a large number of loops substantially consisting of at least one elastic polymer. The loops are attached to the backing cloth according to a loop-pile principle. The shock-absorbing layer can be used as an intermediate layer between a hard surface and a top layer of, for example, sports mats to absorb shocks and impacts and prevent injuries. It is particularly suitable for sports such as gymnastics and judo, where athletes often make hard landings. It can also be integrated into artificial turf installations for added cushioning and injury protection. In addition, it is ideal for use as an underlay for playgrounds and other recreational areas where fall protection is essential.

[0016] The loop-pile structure offers various advantages, including that its fibers are more durable and less prone to wear because the loops are not cut. The loops are also capable of rebounding after being compressed, providing better shock absorption. Moreover, the loop structure ensures better drainage and ventilation, which can improve the lifespan of the shock-absorbing layer and prevent water accumulation, which can cause slipperiness.

[0017] The elastic polymer fibers provide more elasticity and resilience, which leads to better shock absorption and energy return. A resilient polymer, such as a thermoplastic polymer, is preferred for this purpose. Resilient polymers have the ability to return to their original shape or position after compression.

[0018] This shock-absorbing layer also has the surprising advantage that the shock-absorbing layer is fully recyclable. In particular because both the backing cloth and the coating of the shock-absorbing layer are substantially manufactured from polyethylene and/or polypropylene.

[0019] In a second aspect, the invention relates to a method for manufacturing a shock-absorbing layer for an artificial turf installation according to claim 12. Preferred embodiments of the second aspect of the invention are described in claims 13 to 15.

[0020] An advantage of the second aspect of the invention is that a shock-absorbing layer can be easily manufactured by machine in this way. Tufting machines suitable for this purpose are moreover already being used for the manufacture of an artificial turf installation and, consequently, they can also be used for the manufacture of a shock-absorbing layer according to the present invention without cumbersome adjustments.

DESCRIPTION OF THE FlGURES

[0021] Fig. 1 illustrates a schematic representation of a method according to preferred embodiments of the invention for manufacturing a shock-absorbing layer for an artificial turf installation, a shock-absorbing layer being shown as a cross-section.

DETAILED DESCRIPTION

[0022] The invention relates to a shock-absorbing layer.

[0023] Unless otherwise defined, all terms used in the description of the invention, including technical and scientific terms, have the meaning as commonly understood by a person skilled in the art to which the invention pertains. For a better understanding of the description of the invention, the following terms are explained explicitly.

[0024] The term "polymer" refers to a compound consisting of at least two or more monomers. The term "recyclable" refers to materials that can be converted into another material or product for a different or similar use or the extraction of at least one of the individual components or materials of the product for use of that component or material in another product. If the term "fully recyclable" is used, the material or system, in this document, should be understood as a material or system in which all different components can be converted into another material or product for a different or similar use. To be fully recyclable, at least 90% of the carbon present in the product to be recycled must end up in the recycled product, preferably 95% and more preferably 99%. Reuse means that an object is used again, whether or not for a different purpose. In recycling, a waste material is transformed into a new product.

[0025] In this document, "a" and "the" refer to both the singular and the plural, unless the context presupposes otherwise. For example, "a segment" means one or more segments.

[0026] When the term "around" or "about" is used in this document with a measurable quantity, a parameter, a duration or moment, and the like, then variations are meant of approximately 20% or less, preferably approximately 10% or less, more preferably approximately 5% or less, even more preferably approximately 1% or less, and even more preferably approximately 0.1% or less than and of the quoted value, insofar as such variations are applicable in the described invention. However, it must be understood that the value of a quantity used where the term "about" or "around" is used, is itself specifically disclosed.

[0027] The terms "comprise," "comprising," "consist of," "consisting of," "provided with," "have," "having," "include," "including," "contain," "containing" are synonyms and are inclusive or open terms that indicate the presence of what follows, and which do not exclude or prevent the presence of other components, characteristics, elements, members, steps, as known from or disclosed in the prior art.

[0028] Quoting numerical intervals by endpoints comprises all integers, fractions and/or real numbers between the endpoints, these endpoints included.

[0029] In a first aspect, the invention relates to a shock-absorbing layer comprising a backing cloth having a top surface, a bottom surface, and a plurality of loops.

[0030] In particular, the loops are formed from fibers substantially made of at least one elastic polymer, which are attached to the backing cloth according to a loop-pile principle, with the number of loops per unit of area being at least 80,000 loops per m² and at most 160,000 loops per m²;

[0031] The shock-absorbing layer is a versatile layer that can be applied in different ways. It can preferably be used as an intermediate layer between a hard surface and a top layer of sports mats to absorb shocks and impacts and thus prevent injuries. The shock-absorbing layer is therefore ideal as a mat or underlay for a mat for sports such as gymnastics and judo, where athletes often have to make hard landings. This layer helps to absorb the impact of landings, providing a safer and more comfortable training environment.

[0032] The shock-absorbing layer can also be integrated into artificial turf installations to provide extra cushioning and protection against injuries. This not only makes artificial turf fields safer, but also more durable and resistant to wear and tear. The shock-absorbing layer is also ideal for use as an underlay for playgrounds and other recreational areas where fall protection is important.

[0033] The shock-absorbing layer can also be used as a mattress, providing good support and better pressure distribution while sleeping. It can help to reduce pressure points on the body and improve the sleeping experience.

[0034] An important advantage of the shock-absorbing layer made with a loop-pile structure is that it offers a longer lifespan than, for example, a cut tufting, also known as cut-pile. This is because the loops in the loop-pile structure create a dense surface that is suitable for absorbing shocks. The tufted loops are also suitable for springing back after being compressed, making them good at absorbing shocks, which is less the case with traditional cut-pile mats. The loop-pile structure provides more cushioning and resilience, as the fiber loops can move and compress, better absorbing the impact. This is especially important in applications where shock absorption is crucial, such as in sports fields and playgrounds.

[0035] Also, the fibers that are provided as loop-pile are generally more durable than those of cut-pile because the fiber loops are not cut. This means that the fibers wear out less quickly and therefore last longer. In addition, loop-pile fibers are less susceptible to fluff formation, so that the shock-absorbing layer retains its cushioning properties better.

[0036] Finally, a loop-pile shock-absorbing layer offers better drainage and ventilation than a cut-pile layer, because there is more space between the fiber loops to allow water and air to flow through. This can extend the life of the shock-absorbing layer and improve the safety of users by preventing water from accumulating and causing slipperiness.

[0037] According to a preferred embodiment, the fibers comprise an elastic polymer, which provides a higher elasticity and resilience, which leads to improved shock absorption and energy restitution properties. Preferably a resilient polymer such as, for example, a thermoplastic polymer. A resilient polymer is understood to mean a material that in particular has resilient properties and can therefore return to its original shape or position after being compressed. Such polymers can be made from polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), polyamide (PA), ethylene propylene diene monomer (EPDM) or any other suitable polymer.

[0038] According to a further and/or alternative embodiment, the elastic polymer comprises a recycled elastic polymer.

[0039] According to an embodiment, the plurality of loops comprises at least 90 wt% of an elastic polymer chosen from: PE, PP, PVC, PA, EPDM rubber, elastane, isoprene rubber, neoprene, isoprene butyl rubber, polyurethane, natural rubber, siloxanes and hypalon. Preferably, the loops mainly comprise PE or PP.

[0040] According to an embodiment, the loops are arranged in rows, with a distance between the rows of loops being at least 0.05 mm, preferably at least 0.1 mm, preferably at least 0.2 mm, preferably at least 0.3 mm, preferably at least 0.4 mm, preferably at least 0.5 mm, preferably at least 1.0 mm, preferably at least 1.5 mm, preferably at least 2 mm.

[0041] Preferably the distance between the rows is at most 10 mm, preferably at most 9.0 mm, preferably at most 8.0 mm, preferably at most 7.0 mm, preferably at most 6.0 mm, preferably at most 5.0 mm, preferably at most 4.0 mm, preferably at most 3.5 mm, preferably at most 3.0 mm, preferably at most 2.5 mm.

[0042] Preferably, the distance is between the above-mentioned lower and upper limits. This distance is extremely suitable for obtaining a dense surface, suitable for absorbing shocks.

[0043] According to an embodiment, the fibers have a linear mass of at least 250 dtex and at most 5000 dtex, preferably between 1500 dtex and 3500 dtex, more preferably between 2000 dtex and 3000 dtex. The linear mass of the fibers is directly related to their strength. By requiring an optimum minimum linear mass, the invention ensures that the fibers are strong enough to withstand the load they must bear in absorbing shocks. On the other hand, the linear mass should not be too high, as this can limit the flexibility of the fibers and reduce the shock-absorbing properties. By giving preference to fibers with a said linear mass, the optimum balance between strength and flexibility can be achieved. As a result, the shock-absorbing layer will have the required strength to absorb shocks, while at the same time retaining the flexibility of the fibers to ensure maximum shock absorption.

[0044] According to an embodiment, per 10 cm of the backing cloth, the fiber is passed through the backing cloth at least 30 times and at most 140 times, preferably at least 40 times and at most 130 times, preferably at least 50 times and at most 120 times. The length of 10 cm is taken along the direction of the rows of loops. Having a certain number of loops per unit of area and per length of the backing cloth is essential for achieving a good shock-absorbing effect. This creates a sufficient amount of loops to achieve good shock absorption. A higher number of loops per unit of area and per length of the backing cloth results in better shock absorption and increased stability of the surface. In addition, the number of loops increases the durability and life of the shock-absorbing layer. So it is important to have an appropriate number of loops to achieve good performance.

[0045] According to an embodiment, the loops have a pile height of at least 4 mm and at most 12 mm, preferably at least 6 mm and at most 10 mm. The pile height is determined by the distance from the backing cloth to the point on the loop furthest from the backing cloth. The pile height of the loops affects the shock-absorbing properties of the material. A higher pile height does not necessarily mean better shock absorption properties. This optimum pile height is suitable for damping shocks. This is because the loops at this pile height have sufficient freedom of movement to absorb and dampen shocks, but also remain close enough to the backing cloth to provide stability. A pile height that is too high can lead to reduced stability and a pile height that is too low can limit the shock absorption properties. The pile height must therefore be carefully selected based on the intended application and the required shock absorption properties.

[0046] According to an embodiment, the shock-absorbing layer is provided with a coating, applied to the backing cloth, suitable for fixing the loops. Preferably, the coating is applied to the top surface of the backing cloth. The use of a coating on the shock-absorbing layer can offer several advantages. Firstly, the coating can ensure better adhesion of the loops to the backing cloth, making the shock-absorbing layer more durable and less likely to wear out. In addition, the coating can help keep the loops in place and prevent them from shifting or coming loose. This can result in a more uniform and reliable shock-absorbing layer. Finally, the coating can also help to improve the shock-absorbing layer's resistance to moisture and other external influences.

[0047] According to an embodiment, the coating comprises polyethylene, polypropylene, or a combination of both. Preferably, the primary coating consists of at least 50 wt% of polyethylene and/or polypropylene, preferably 70 wt%, more preferably 90 wt% and most preferably 99 wt% of polyethylene and/or polypropylene. Polyethylene and polypropylene are both thermoplastic polymers widely used for their properties such as flexibility, durability, lightness and chemical resistance. These properties make them suitable for various applications, including the coating of the shock-absorbing layer. Polyethylene and polypropylene are also relatively inexpensive compared to other polymers, making the use of these materials as a coating for the shock-absorbing layer cost-effective. In addition, these materials are not harmful to the environment and can be recycled. Opting for a combination of the two materials optionally offers the possibility of combining the properties of both polymers to create an optimal coating with a balanced combination of strength, flexibility and adhesion.

[0048] Alternatively, it can also be chosen not to use a coating. The tufting of the fibers namely creates a firm connection between the fibers and the backing cloth, making the shock-absorbing layer durable and resistant to wear and deformation. This can possibly lead to material savings because no additional coating is required.

[0049] According to an embodiment, the backing cloth is substantially manufactured from polyethylene, polypropylene or a combination of both. Preferably, the backing cloth consists of at least 50 wt% of polyethylene and/or polypropylene, preferably 70 wt%, more preferably 90 wt% and most preferably 99 wt% of polyethylene and/or polypropylene. In a particularly preferred embodiment, the backing cloth comprises a woven polypropylene layer. The use of polyethylene, polypropylene or a combination of both as the main material for the backing cloth has several advantages. These materials are lightweight, making the backing cloth easy to handle and install. In addition, they are durable and resistant to wear and deformation, so that the backing cloth has a long life and is suitable for intensive use. The woven polypropylene layer in the particularly preferred embodiment provides extra strength and stability to the backing cloth, which is essential for tufting the fibers. The backing cloth serves as a backing for the tufting, so it must be strong enough to hold the fibers in place and prevent them from shifting or coming loose.

[0050] Such embodiments have the surprising advantage that the shock-absorbing layer is recyclable, preferably even fully recyclable. In particular because both the backing cloth and the coating of the shock-absorbing layer are substantially manufactured from polyethylene and/or polypropylene.

[0051] According to an embodiment, the backing cloth has a weight of at least 150 g/m², preferably at least 160 g/m², preferably at least 170 g/m², preferably at least 180 g/m², preferably at least 190 g/m², preferably at least 200 g/m², preferably at least 210 g/m², preferably at least 220 g/m², preferably at least 230 g/m², preferably at least 240 g/m², and at most 350 g/m², preferably at most 340 g/m², preferably at most 330 g/m², preferably at most 320 g/m², preferably at most 310 g/m², preferably at most 300 g/m², preferably at most 290 g/m², preferably at most 280 g/m², preferably at most 270 g/m², preferably at most 260 g/m². An important advantage of a backing cloth with the said weight is that the cloth is sturdy and durable. It can absorb the shocks that occur when using the shock-absorbing layer and can support the weight of the material used. In addition, a heavier backing cloth provides better protection against root penetration and wear, thus extending the life of the shock-absorbing material. However, a lighter backing cloth can also have advantages, such as lower costs and better water permeability. The weight of the backing cloth therefore depends on the application and the desired properties.

[0052] According to an embodiment, the shock-absorbing layer has a pile weight of at most 5.0 kg/m², preferably at most 4.0 kg/m², preferably at most 3.0 kg/m², preferably at most 2.5 kg/m², preferably at most 2.0 kg/m², preferably at most 1.5 kg/m², preferably at most 1.0 kg/m². The pile weight is the weight of the fibers per square meter. It indicates how tightly the fibers are tufted together. A higher pile weight means that more fibers are used per square meter, which can provide more shock absorption and comfort. However, it is also important to look at the composition and density of the fibers, as these also influence the shock-absorbing properties. Said pile weight has the effect that the shock-absorbing layer is light and easy to handle. This makes it easier to install and move the shock-absorbing layer if necessary.

[0053] According to an embodiment, the shock-absorbing layer has a thickness of at least 0.1 mm, preferably at least 0.5 mm, preferably at least 1 mm, preferably at least 2 mm, and at most 100 mm, preferably at most 75 mm, preferably at most 50 mm. This thickness offers a higher degree of protection against bumps and falls, which increases the safety of users. Said thickness of the layer is also optimal for use in various applications.

[0054] According to a preferred embodiment of the first aspect of the invention, the shock-absorbing layer also comprises a plurality of perforations. Such an embodiment has the advantage that the ability to discharge liquids, such as water, is greatly increased.

[0055] According to a preferred embodiment, the shock-absorbing layer has a shock absorption, measured according to EN 14808, of at least 15% and preferably at least 30%. Because the shock-absorbing layer has a shock absorption of at least 15%, this shock-absorbing layer is very suitable for improving the shock absorption and energy restitution properties of the artificial turf installation.

[0056] According to a preferred embodiment, the shock-absorbing layer has a tensile strength, measured in accordance with EN 12230, of at least 0.10 MPa and preferably at least 0.15 MPa. Because the shock-absorbing layer has a tensile strength of at least 0.10 MPa, the layer is sufficiently strong to absorb the forces developed by users of the artificial turf installation.

[0057] According to a preferred embodiment, the water permeability of the shock-absorbing layer, measured according to EN 12616, is at least 180 mm/h.

[0058] In a second aspect, the invention relates to a method for manufacturing a shock-absorbing layer, comprising providing a backing cloth and arranging fibers in the backing cloth by means of tufting on a tufting machine.

[0059] In particular, the method comprises tufting the fibers with a pile height between at least 4 mm and at most 12 mm, wherein the fibers are tufted in loops according to a loop-pile, the number of loops per unit of area being at least 100,000 loops per m² and no more than 140,000 loops per m².

[0060] According to an embodiment, the loops have a cross-section that is circular, preferably with a diameter of 0.2-30 mm. According to an embodiment, the loops have a grass-shaped cross-section, preferably with a maximum thickness of 0.2-1 mm and a length of 0.5-3 mm. According to an embodiment, the loops have a donut-shaped cross-section, preferably the cavity inside has a diameter of 0.2-10 mm and the outer diameter of the cross-section of the loop is 1.2-3 times the diameter of this cavity. According to an embodiment, the loops have an eclipse-shaped cross-section, preferably with a maximum thickness of 0.2-1 mm and a length of 0.5-3 mm. According to an embodiment, the loops are arranged in parallel straight rows. According to an embodiment, the loops are arranged in parallel zigzag rows.

[0061] This method is advantageous because it produces a shock-absorbing layer that is both durable and effective in absorbing shock and vibration. By tufting the fibers in loops according to a loop-pile, a resilient layer is created that has excellent shock-absorption properties. In addition, the use of a backing cloth as a base for the fibers ensures that the layer remains firm and stable, which is important for maintaining the shock absorption properties in the long term. The method specifications, such as the pile height and the number of loops per unit of area, are also important because the shock absorption is optimized without compromising the durability of the layer.

[0062] A further advantage of this method is that it can be carried out easily by machine. Tufting machines suitable for this purpose are moreover already being used for the manufacture of, for example, an artificial turf installation and, consequently, they can also be used for the manufacture of a shock-absorbing layer according to the present invention without cumbersome adjustments.

[0063] It should also be noted that a loop-pile shock-absorbing layer is better than a cut-pile shock-absorbing layer for several reasons. First, a loop-pile structure provides more cushioning and resilience because the loops of the fibers can move and compress, better absorbing impacts. This is especially important in applications where shock absorption is crucial, such as in sports fields or playgrounds. Second, loop-pile fibers are generally more durable than cut-pile fibers because the loops are not cut. This means that the fibers wear out less quickly and therefore last longer. In addition, loop-pile fibers are less susceptible to fluff formation, so that the shock-absorbing layer retains its cushioning properties better. Finally, a loop-pile shock-absorbing layer offers better drainage and ventilation than a cut-pile layer, because there is more space between the loops for water and air to flow through. This can extend the life of the shock-absorbing layer and improve the safety of users by preventing water from accumulating and causing slipperiness.

[0064] According to an embodiment, the tufting machine uses a needle density of at least 0.15 cm and at most 0.35 cm. A higher needle density means that the fibers are fixed more firmly in the backing cloth. As a result, the shock-absorbing layer stays in place better and retains its shape, even with intensive use. It also ensures that the fibers are better secured and that the loops become firmer. This not only improves the durability of the layer, but also provides better shock absorption. The fibers are more evenly distributed over the backing cloth. This creates a more uniform density of the fibers, which contributes to better shock absorption and stability. Furthermore, less material will be wasted because the fibers are better secured and fewer fibers are pulled out of the backing cloth during tufting.

[0065] According to an embodiment, a coating is applied to the backing cloth for fixing the loops. Applying a coating to the backing cloth before fixing the loops has various advantages for producing a shock-absorbing layer. First, the coating helps to better secure the loops of the fibers and protect the fibers from damage. This improves the durability of the shock-absorbing layer and makes it more resistant to intensive use and wear. Another advantage of using a coating is that it ensures better adhesion of the fibers to the backing cloth. This results in a more uniform and consistent layer with better stability and shock absorption. In addition, the coating prevents the fibers from shifting or coming loose during tufting, resulting in better quality loops. Finally, the coating helps to reduce material waste and optimize the use of raw materials. It reduces the chance of fibers coming loose during the production process, resulting in less material loss and more efficient use of available raw materials.

[0066] In short, applying a coating to the backing cloth is an important step in the production of a shock-absorbing layer. It contributes to the durability and stability of the layer and improves the quality of the loops. In addition, it reduces material waste and optimizes the use of raw materials.

[0067] According to an embodiment, per 10 cm of the backing cloth, the fibers are passed through the backing cloth at least 30 times and at most 140 times, preferably at least 40 times and at most 130 times, preferably at least 50 times and at most 120 times. Having a certain number of loops per unit of area and per length of the backing cloth is essential for achieving a good shock-absorbing effect. This creates a sufficient amount of loops to achieve good shock absorption. A higher number of loops per unit of area and per length of the backing cloth results in better shock absorption and increased stability of the surface. In addition, the number of loops increases the durability and life of the shock-absorbing layer. So it is important to have an appropriate number of loops to achieve good performance.

[0068] According to an embodiment, the distance between the rows of loops is at least 0.05 mm, preferably at least 0.1 mm, preferably at least 0.2 mm, preferably at least 0.3 mm, preferably at least 0.4 mm, preferably at least 0.5 mm, preferably at least 1.0 mm, preferably at least 1.5 mm, preferably at least 2 mm and at most 10 mm, preferably at most 9.0 mm, preferably at most 8.0 mm, preferably at most 7.0 mm, preferably at most 6.0 mm, preferably at most 5.0 mm, preferably at most 4.0 mm, preferably at most 3.5 mm, preferably at most 3.0 mm, preferably at most 2.5 mm. This distance is extremely suitable for obtaining a dense surface, suitable for absorbing shocks.

[0069] For example, but not being limited thereto, the invention relates to the shock-absorbing layer as described herein as a layer for use in an artificial turf installation, wherein the shock-absorbing layer is arranged between the surface and artificial turf installation. The shock-absorbing layer is preferably placed under the backing cloth of the artificial turf installation. As a result, the artificial turf installation will have shock-absorbing properties. This shock-absorbing layer reduces complaints for users of the surface. Alternative shock-absorbing agents, such as a filler made of elastic granules, have the disadvantage that they wear quickly and erode off the terrain. The shock-absorbing layer under the artificial turf installation has a long service life. Moreover, it does not affect playing characteristics such as the rolling of the ball or the elasticity of the tufts.

[0070] One skilled in the art will appreciate that a method according to the second aspect is preferably carried out for manufacturing a shock-absorbing layer according to the first aspect. Each feature described in this document, both above and below, can therefore relate to any of these two aspects of the present invention.

[0071] In what follows, the invention is described by way of non-limiting figures illustrating the invention, and which are not intended to and should not be interpreted as limiting the scope of the invention.

FIGURES

[0072] A method for manufacturing a shock-absorbing layer, suitable, inter alia, as an intermediate layer in an artificial turf installation, according to preferred embodiments of the invention is shown in Fig. 1. In a first step of method (i) a backing cloth 2 is herein tufted, preferably by machine. At least one elastic polymer 5 is thus tufted into the backing cloth 2 in a loop pile. When an elastic polymer 5 is tufted into the backing cloth 2, loop-shaped loops 6 extend along both a top surface 3 and a bottom surface 4 of the backing cloth 2. Subsequently, in a second step of the method (ii), a liquid coating 7 is applied either to the top surface 3 or to the bottom surface 4 of the backing cloth 2 so that the loops 6 of the elastic polymer 5 are fixed along one side of the backing cloth 2. Afterwards, the liquid coating 7 is finally cured, resulting in a manufactured shock-absorbing layer 1. Finally, the shock-absorbing layer 1 is perforated in a third step (iii) to improve drainage. Perforations 7 are here made in the coating of the shock-absorbing layer 1.

[0073] Below is an overview of the meaning of the numbers used in the figures:

1 shock-absorbing layer

2 backing cloth

3 top surface backing cloth

4 bottom surface backing cloth

5 elastic polymer

6 loops

7 coating

8 perforation

(i) first method step

(ii) second method step

(iii) third method step

[0074] The present invention should not be construed as being limited to the embodiments described above and certain modifications or changes may be added to the examples described without having to re-evaluate the appended claims.

Claims

1. A shock-absorbing layer comprising a backing cloth having a top surface, a bottom surface, and a plurality of loops, characterized in that the loops are formed from fibers substantially made of at least one elastic polymer, which are attached to the backing cloth according to a loop-pile principle, with the number of loops per unit of area being at least 80,000 loops per m² and at most 160,000 loops per m².

2. A shock-absorbing layer according to claim 1, characterized in that the loops are arranged in rows, wherein a distance between the rows of loops is between at least 0.05 mm and at most 3.5 mm.

3. A shock-absorbing layer according to claim 1 or 2, characterized in that the fibers have a linear mass of at least 250 dtex and at most 5000 dtex, preferably between 1500 dtex and 3500 dtex, more preferably between 2000 dtex and 3000 dtex.

4. A shock-absorbing layer according to any of the preceding claims 1 to 3, characterized in that, per 10 cm of the backing cloth, the fibers are passed through the backing cloth at least 30 times and at most 140 times.

5. A shock-absorbing layer according to any of the preceding claims 1 to 4, characterized in that the loops have a pile height of at least 4 mm and at most 12 mm, preferably at least 6 mm and at most 10 mm.

6. A shock-absorbing layer according to any of the preceding claims 1 to 5, characterized in that, the shock-absorbing layer comprises a coating, applied to the backing cloth, suitable for fixing the loops.

7. A shock-absorbing layer according to claim 6, characterized in that the coating comprises polyethylene, polypropylene or a combination of both.

8. A shock-absorbing layer according to any of the preceding claims 1 to 7, characterized in that the backing cloth is substantially manufactured from polyethylene, polypropylene or a combination of both.

9. A shock-absorbing layer according to any of the preceding claims 1 to 8, characterized in that the backing cloth has a weight of at least 150 g/m² and at most 350 g/m².

10. A shock-absorbing layer according to any of the preceding claims 1 to 9, characterized in that the shock-absorbing layer has a pile weight of at most 2.5 kg/m².

11. shock-absorbing layer according to any of the preceding claims 1 to 10, characterized in that the shock-absorbing layer has a thickness of at least 0.1 mm and at most 100 mm.

12. Method for manufacturing a shock-absorbing layer, comprising:

a. providing a backing cloth;

b. applying fibers in the backing cloth by means of tufting on a tufting machine;

characterized in that the fibers are tufted with a pile height between at least 4 mm and at most 12 mm, wherein the fibers are tufted in loops according to a loop-pile, the number of loops per unit of area being at least 100,000 loops per m² and no more than 140,000 loops per m².

13. Method according to claim 12, characterized in that the tufting machine uses a needle density of at least 0.15 cm and at most 0.35 cm.

14. Method according to claim 12 or 13, characterized in that a coating is applied to the backing cloth for fixing the loops.

15. Method according to claims 12 to 14, characterized in that, per 10 cm of the backing cloth, the fibers are passed through the backing cloth at least 30 times and at most 140 times.

Drawing