Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C13/00—Pavings or foundations specially adapted for playgrounds or sports grounds; Drainage, irrigation or heating of sports grounds
  • E01C13/08—Surfaces simulating grass ; Grass-grown sports grounds
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F1/00—General methods for the manufacture of artificial filaments or the like
  • D01F1/02—Addition of substances to the spinning solution or to the melt
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
  • D06N7/00—Flexible sheet materials not otherwise provided for, e.g. textile threads, filaments, yarns or tow, glued on macromolecular material
  • D06N7/0063—Floor covering on textile basis comprising a fibrous top layer being coated at the back with at least one polymer layer, e.g. carpets, rugs, synthetic turf
  • D06N7/0065—Floor covering on textile basis comprising a fibrous top layer being coated at the back with at least one polymer layer, e.g. carpets, rugs, synthetic turf characterised by the pile

Definitions

• the invention relates to a device for artificial grass mats.
• the invention also relates to a method for manufacturing an artificial turf mat.
• Artificial turf mats are known in the prior art for various applications, including for sports fields.
• artificial turf mats for use on sports fields for example hockey fields, need to be irrigated with water before and/or during play on the artificial turf mats, in order to improve their playing characteristics.
• Such irrigated artificial turf mats are also referred to as water-based pitches.
• EP 4321685 describes an artificial turf mat designed for various applications.
• the artificial turf mat comprises a primary backing with an upper side and a lower side, tufts protruding above the upper side, and a primary coating on the lower side of the primary backing to secure the tufts.
• Two types of filaments are used in this regard: crimped filaments and substantially straight or spiral-shaped filaments. This plurality of filaments allows for a limited reduction in the friction of the artificial turf mat, thereby improving ball roll movement on the artificial turf mat.
• the artificial turf mat as described in EP 4321685 fails to approximate or equal all playing characteristics of a water-based pitch, for example, with regard to resistance, running comfort, and playing comfort.
• AU 2022 305 790 discloses a sports surface comprising loop-shaped pile fibers. To reduce friction and to facilitate managing the need for water irrigation, the loop-shaped pile fibers can remain uncut.
• US 2022/025587 describes artificial turf filaments in a core-and-shell structure, comprising polymer particles with different refractive indices to achieve a natural grass-like appearance.
• US 2021/404126 describes an artificial turf system that combines primary straight fibers with secondary textured fibers at different heights to create an infill-free playing surface.
• the present invention aims to provide at least a solution for some of the above-mentioned problems or disadvantages.
• the aim of the invention is to provide a method which eliminates those disadvantages.
• the present invention relates to an artificial turf mat according to claim 1.
• Artificial turf mats for sports fields comprising filaments with a rounded cross-section provide improved flexibility and softness compared to filaments with a non-rounded cross-section. Consequently, a consistent and fast ball roll movement can be obtained on an artificial turf mat according to the invention. Moreover, the artificial turf mats can feel comfortable for players to run and play on. Furthermore, a largest cross-sectional dimension of the filaments of less than 250 ⁇ m may contribute to an even higher flexibility compared to filaments merely having a rounded cross-section. In this context, the presence of the processing aid additive is also advantageous. A combination of all these features is advantageous, whereby hardly any or no infill material is required between the filaments.
• the present invention relates to a method for manufacturing an artificial turf mat according to claim 13.
• the method is advantageous because a combination of sufficient stiffness and sufficient flexibility of the filaments is obtained. Moreover, no infill material is needed on the artificial turf mat.
• the present invention relates to a use of an artificial turf mat according to claim 14.
• a preferred embodiment of this use is set forth in claim 15.
• the invention relates to an artificial turf mat.
• a segment means one or more segments.
• Quoting numeric intervals by the endpoints includes all integers, fractions, and/or real numbers between the endpoints, including those endpoints.
• filaments are to be interpreted as thin, thread-like structures, which constitute raw materials for the textile industry.
• filament is used for structures of limited length
• continuous filament is used for continuous structures.
• the term “yarn” is to be understood as a continuous material composed of two or more filaments. Yarn is typically obtained by twisting said two or more filaments.
• the filaments and yarn as described herein are suitable for use in artificial turf mats according to the present invention.
• tufting of filaments means that filaments extend at least partially from a front side of the primary backing. The filaments are thereby at least partially exposed on a rear side of the primary backing in the form of stitch loops.
• the artificial turf mat according to the invention comprises a primary backing, with a front side and an opposing rear side; a plurality of filaments made of synthetic material, wherein the filaments are tufted through the primary backing; and a coating, which is located on the rear side of the primary backing.
• the filaments have a rounded cross-section, and one or more of the following features are present: a largest cross-sectional dimension of the filaments is less than 250 ⁇ m, and/or said filaments comprise a processing aid additive.
• This embodiment is advantageous for artificial turf mats for sports fields, as the rounded cross-section provides more flexible and softer filaments compared to filaments with a non-rounded cross-section. Consequently, a consistent and fast ball roll movement can be obtained. Moreover, the artificial turf mats can feel comfortable for players to run and play on. Furthermore, the largest cross-sectional dimension of the filaments being less than 250 ⁇ m contributes to a higher flexibility compared to filaments that only have a rounded cross-section. Alternatively or in combination with the largest cross-sectional dimension as described herein, the presence of a processing aid additive provides a reduction of frictional resistance at the surface of the fibers, compared to filaments that only have a rounded cross-section.
• both features are present.
• the rounded cross-section of the filaments is a polygon with rounded corners.
• the corner radius of the rounded corners is at least 5 ⁇ m, more preferably at least 10 ⁇ m, more preferably at least 25 ⁇ m, more preferably at least 50 ⁇ m.
• the corner radius of the rounded corners is at most 150 ⁇ m, more preferably at most 125 ⁇ m, more preferably at most 100 ⁇ m, more preferably at most 75 ⁇ m.
• the corner radius of the rounded corners is comprised between 5 and 150 ⁇ m, between 10 and 125 ⁇ m, between 25 and 100 ⁇ m, most preferably between 50 and 75 ⁇ m.
• the largest cross-sectional dimension of the filaments is comprised between 75 ⁇ m and 250 ⁇ m.
• the largest cross-sectional dimension of the filaments is less than or equal to 225 ⁇ m, preferably less than or equal to 200 ⁇ m.
• the largest cross-sectional dimension of the filaments is greater than or equal to 100 ⁇ m, preferably greater than or equal to 150 ⁇ m.
• the largest cross-sectional dimension of the filaments is comprised between 100 and 225 ⁇ m, preferably comprised between 150 and 200 ⁇ m.
• Sufficient stiffness of the filaments may mean that the filaments have an elastic modulus of at least 5 N measured according to EN 13864, preferably with a maximum of 25 N, whereby the filaments retain good flexibility.
• the smallest cross-sectional dimension of the filaments is comprised between 25 ⁇ m and 250 ⁇ m.
• the smallest cross-sectional dimension of the filaments is less than or equal to 200 ⁇ m, preferably less than or equal to 150 ⁇ m.
• the smallest cross-sectional dimension of the filaments is greater than or equal to 50 ⁇ m, preferably greater than or equal to 75 ⁇ m, preferably greater than or equal to 100 ⁇ m.
• the smallest cross-sectional dimension of the filaments is comprised between 50 and 200 ⁇ m, preferably comprised between 75 and 100 ⁇ m.
• the cross-sectional dimensions described herein contribute to improved UV resistance, in combination with sufficient stiffness of the filaments. UV resistance means that the filaments do not break as a result of degradation from exposure to UV light, which causes the filaments to become brittle from the surface. Sufficient UV resistance is determined by means of weathering tests according to EN 14836, method 2.
• the processing aid additive is a siloxane additive.
• the siloxane additive imparts a smoother feel to the filaments, whereby, inter alia, the resistance at a surface of the filaments is reduced.
• the siloxane additive is a nonionic siloxane oil; more preferably, the siloxane additive is a polyether-modified polysiloxane oil. This oil further acts as a lubricant and as a dispersion component.
• Alternative processing aid additives besides siloxane additive may include: a polyoxyalkylalkene such as polyethylene glycol, or a polyfluoroalkyl such as perfluorooctanoic acid, or a polyacrylate such as poly(ethyl methacrylate).
• the processing aid additive aims to improve the processing of the extruded filaments during extrusion, whereby, inter alia, die drool is reduced.
• the processing aid additive has a number-average molecular weight comprised between 1000 g/mol and 50000 g/mol.
• the number-average molecular weight is at least 1500 g/mol, more preferably 2000 g/mol, more preferably 2500 g/mol.
• the number-average molecular weight is at most 35000 g/mol, more preferably at most 20000 g/mol, more preferably at most 5000 g/mol.
• the processing aid additive has a number-average molecular weight comprised between 1500 and 35000 g/mol, preferably between 2000 and 20000 g/mol, more preferably between 2500 and 5000 g/mol.
• the processing aid additive is present in the filaments in an amount of 0.1 wt% to 10 wt%, where weight percentages are expressed relative to the total weight for making a compound for production of the continuous extruded filaments.
• the processing aid additive is present in an amount of 0.3 wt% to 5 wt%, more preferably 0.5 wt% to 4.0 wt%, more preferably 0.7 wt% to 3 wt%.
• the filaments comprise a microstructure on their surface.
• the microstructure in the context of the present invention is preferably a microstructure that extends longitudinally along the length of the filament. More preferably, the microstructure is uniform over each cross-section of the filament, perpendicular to the longitudinal axis of the filament.
• the microstructure may possibly be achieved by extrusion through a die plate comprising openings which form the microstructure on their circumferential edge.
• the microstructure comprises a sinusoidal pattern.
• this sinusoidal pattern extends longitudinally along the length of the filament. More preferably, this sinusoidal pattern is uniform over each cross-section of the filament, perpendicular to the longitudinal axis of the filament.
• the sinusoidal pattern has an amplitude comprised between 1 ⁇ m and 25 ⁇ m, preferably between 2 ⁇ m and 20 ⁇ m, more preferably 3 ⁇ m and 15 ⁇ m, even more preferably 4 ⁇ m to 10 ⁇ m.
• the amplitude of the sinusoidal pattern is at least 1.5 ⁇ m, preferably at least 2.5 ⁇ m, more preferably at least 3.5 ⁇ m.
• the amplitude of the sinusoidal pattern is at most 12.0 ⁇ m, preferably at most 9.0 ⁇ m, more preferably at most 6.0 ⁇ m.
• the sinusoidal pattern has a wavelength comprised between 1 ⁇ m and 50 ⁇ m, preferably between 2 ⁇ m and 25 ⁇ m, more preferably between 3 ⁇ m and 15 ⁇ m.
• the wavelength of the sinusoidal pattern is at least 2 ⁇ m, preferably at least 4 ⁇ m, more preferably at least 6 ⁇ m, more preferably at least 8 ⁇ m, more preferably at least 10 ⁇ m.
• the wavelength of the sinusoidal pattern is at most 40 ⁇ m, preferably at most 30 ⁇ m, more preferably at most 20 ⁇ m, more preferably at most 10 ⁇ m.
• the wavelength and amplitude of the sinusoidal pattern as described herein contribute to a ball roll distance of at least 8.5 ⁇ 0.5 m. Due to the lower friction, a ball can roll further with the same applied force. This is due to the increased flexibility of the filaments.
• the ball roll distance is determined according to the standards of the International Hockey Federation for dry artificial turf mats.
• the microstructure of the filaments contributes to a shock-absorbing effect.
• the cross-section of the filaments is elliptical.
• the cross-section of the filaments is circular. Owing to the elliptical, preferably circular, cross-section of the filaments, an improved balance can be obtained between stiffness and flexibility of the filaments.
• a ratio of the longest diameter to the shortest diameter of the elliptical cross-section is at most 2, more preferably at most 1.5, more preferably at most 1.3, more preferably at most 1.1. Even more preferably, said ratio is at least 1.
• a number of tufts per unit area is at most 97,000 tufts/m 2 , more preferably at most 94,000 tufts/m 2 , more preferably at most 91,000 tufts/m 2 , more preferably at least 88,000 tufts/m 2 , more preferably at least 85,000 tufts/m 2 .
• the number of tufts per unit area of the artificial turf mat is comprised between 63,000 and 97,000 tufts/m 2 , preferably comprised between 66,000 and 94,000 tufts/m 2 , more preferably comprised between 69,000 and 91,000 tufts/m 2 , even more preferably between 71,000 and 85,000 tufts/m 2 .
• tufts/m 2 Due to the presence of at least 60,000 tufts/m 2 , there is sufficient coverage so that the primary backing is not visible and can provide sufficient shock absorption. Moreover, a tuft density of at most 100,000 tufts/m 2 allows sufficient movement of the tufts. A further advantage is that the filaments are thereby more wear-resistant.
• the portion of the filaments which extends from the primary backing, preferably from the front side of the primary backing, to the distal end of the filaments, has a length of at least 8 mm and at most 15 mm.
• the length is at most 14.5 mm, more preferably at most 14.0 mm, more preferably at most 13.5 mm, more preferably at most 13.0 mm.
• the length is at least 8.0 mm, more preferably at least 8.2 mm, more preferably at least 8.5 mm.
• the portion of the filaments which extends from the primary backing to the distal end of the filaments has a length comprised between 8.0 and 14.5 mm, preferably comprised between 8.2 and 14.0 mm, more preferably comprised between 8.5 and 13.5 mm, most preferably between 8.5 and 13.0 cm. Due to the length of the filaments of at least 8 mm and at most 15 mm, the filaments can remain upright if there is no compression of the filaments. At the same time, there is sufficient flexibility of the filaments without folds being able to form in the filaments. Moreover, shorter filaments provide a lower resistance to ball roll movement. The length as described herein contributes to a further improvement of stiffness and flexibility of the filaments.
• a filament is a segment of a continuous filament.
• the filament has a length of at least 17 mm and at most 30 mm.
• the filament has a length of at least 19 mm, more preferably at least 21 mm.
• the filament has a length of at most 28 mm, more preferably at most 26 mm.
• the filament has a length comprised between 19 and 28 mm, preferably comprised between 21 and 26 mm.
• the artificial turf mat comprises no infill material.
• sand, elastic particles, whether foamed or not, or water are typically used for keeping the filaments upright, i.e., as infill material.
• the artificial turf mat may comprise one or more infill materials.
• functionalities such as shock absorption can possibly be further improved.
• the filaments comprise a UV additive.
• the UV additive is a UV absorber, a hindered amine light stabilizer, an antioxidant, or a combination thereof, whereby the filaments are more UV-resistant than without the UV additive.
• the UV additive is comprised in the filaments in 0.1 wt% to 1.0 wt%.
• the filaments comprise a filler.
• the filler is calcium carbonate, more preferably, the calcium carbonate is micronized.
• the filler contributes to a microstructure on the surface of the filaments and can additionally contribute to antiblocking properties of the filaments with respect to each other.
• the filler is incorporated in the filaments in 0.3 wt% to 1.0 wt%.
• the artificial turf mat comprises between 1 and 3 million filaments per square meter. Preferably at least 1.5 million filaments per square meter and at most 2.5 million filaments per square meter. Preferably, the artificial turf mat comprises at least 1.6 million filaments/m 2 , more preferably at least 1.7 million filaments/m 2 . Preferably, the artificial turf mat comprises at most 2.2 million filaments/m 2 , more preferably at most 2.0 million filaments/m 2 . According to some embodiments, the artificial turf mat comprises between 1.6 and 2.2 million filaments per square meter, preferably between 1.7 and 2.0 million filaments per square meter.
• the filaments are monofilaments.
• the artificial turf mat has a pile weight of at least 1000 g/m 2 , preferably of at least 1500 g/m 2 , more preferably of 2000 g/m 2 , and the artificial turf mat has a pile weight of at most 3500 g/m 2 .
• pile weight in the context of the present invention refers to the total weight of the filaments used per square meter of the artificial turf mat. Due to short filaments with a length of at most 15 mm, the pile weight is low, which simplifies placement of the artificial turf mats. Additionally, the pile weight gives an indication of the number of tufts and the number of filaments per unit area.
• the primary backing includes a fiberglass mat.
• the primary backing comprises one to three layers of woven or non-woven textile.
• the textile can be made of polypropylene, polyester, or other synthetic materials.
• the primary backing is a woven polyolefin fabric, whereby recycling of the artificial turf mat is simplified.
• the primary backing consists of three layers wherein the outer layers comprise a woven and/or non-woven material and the middle layer comprises a dimensionally stabilizing woven or non-woven material, such as, for example, the fiberglass mat. Due to the fiberglass mat, the primary backing obtains a reinforced form, whereby fatigue of the primary backing due to deformation is considerably reduced.
• the primary backing has a weight comprised between 250 g/m 2 and 500 g/m 2 .
• the primary backing has a weight of at least 300 g/m 2 , more preferably of at least 350 g/m 2 .
• the primary backing has a weight of at most 450 g/m 2 , more preferably of at least 400 g/m 2 .
• the rotational resistance of the artificial turf mat is between 25 and 50 Nm, measured according to standard EN 15301-1. This ensures that the artificial turf mat provides sufficient grip for users, so that users do not slip. This consequently prevents injuries.
• the vertical deformation of the artificial turf mat is 4 mm to 9 mm, measured according to standard EN 14809.
• the artificial turf mat is a woven mat, a needle-felted mat, a knitted mat, or a mat produced using a velour technique.
• the filaments incorporated in the artificial turf mat have rounded cross-sections.
• the largest cross-sectional dimension of the filaments is less than 250 ⁇ m, and/or said filaments comprise a processing aid additive.
• the above-mentioned features of the filaments for making the tufts are likewise applicable to the filaments used in woven, needle-felted, knitted or mats produced using a velour technique.
• the method comprises the steps of: providing a primary backing, having a front side and an opposite rear side, a plurality of filaments made of synthetic material, and a coating; tufting said filaments through the primary backing, preferably the front side of the primary backing; fixing said filaments by means of applying and curing the coating on the rear side of the primary backing.
• the underlay is laminated to the coating during curing.
• the filaments are extruded from a compound, cold-drawn, and finished with several sequential annealing and drawing steps.
• the invention relates to a use of an artificial turf mat for sports fields.
• the sports fields are hockey fields.
• the combination of several features of the artificial turf mat allows a sufficient stiffness of the filaments to be obtained such that they can remain upright independently and support each other.
• the filaments also exhibit a reduced frictional resistance, resulting in increased playing comfort for players.
• this artificial turf mat does not require irrigation for playing hockey.
• the invention relates to the use of filaments as described in preceding aspects for producing mats other than artificial turf mats.
• the several features of the filaments as described in preceding aspects are also applicable to the use according to the fourth aspect.
• Example 2 concerns an artificial turf mat comprising a plurality of filaments, a primary backing and a coating; for sports fields with the features below: fiber cross section round largest cross-sectional dimension 188-203 ⁇ m smallest cross-sectional dimension 196-206 ⁇ m microstructure amplitude 0.9 ⁇ 0.2 mm microstructure wavelength 2.1 ⁇ 0.1 mm length 75 wt%°: 13 mm, 25 wt%°: 10 mm synthetic material low-density polyethylene additives siloxane additive 2.5 wt%*, UV additive 0.2 wt%* artificial turf mat filaments tufts per square meter 79,560 tufts/m 2 filaments per tuft 9 number of filaments per square meter 1,432,080 filaments/m 2 primary backing foam thickness 6 mm synthetic material additional layer thermoplastic polyurethane elastomer thickness additional layer 15.5 mm yarn density 5500 dtex first layer non-woven polypropylene with long glass fibers coating synthetic material polyurethane elastomer °

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• Textile Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Architecture (AREA)
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• Structural Engineering (AREA)
• Road Paving Structures (AREA)

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Citations (6)

• 2024
  • 2024-06-14 BE BE20245353A patent/BE1032696B1/nl active IP Right Grant
• 2025
  • 2025-06-12 EP EP25182431.4A patent/EP4663851A1/fr active Pending

Patent Citations (6)

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