GB1320868A - Synthetic grass - Google Patents

Abstract

1320868 Synthetic grass for playing fields POLIGRAS GES FUR SPORT-UND RASENTEPPICHE mbH 18 Oct 1971 [17 Oct 1970] 48353/71 Heading A6D [Also in Divisions B2 Dl and E1] Synthetic grass 18 which is arranged over drainage layers 8, 10, 6, for example to form a playing field, comprises a water-permeable textile base support 16 which carries the grass pile 18 and has on the back thereof a coating which is restricted to elevated portions of the textile knit. In between the coated portions of the base support 16 apertures ensures the ready draining-off of water from the grass pile. As shown, a resilient underlay 14 is interposed between the textile base 16 and a top drainage layer 8 to improve the tread properties of the grass. The synthetic grass together with the textile base and underlay are laid in sections as shown in Fig. 1 and are secured to the ground base by locking members 22 inserted in channel-shaped metal sections 12 having bent-out teeth 20 laid on concrete support ribs 4. The members 22 may be used to mark out the playing area. The elevated ribs in the textile support 16 are formed in the knitting process, which may be of the Raschel type, at the regions where the pile 18 emerges from the support and while these ribs are being coated, such as with PVC dispersions, the support is stretched to ensure the formation of drainage apertures (32) (Fig. 10 not shown) (see Division B2 and D1). The grass pile 18 may be of polypropylene and nylon and the base support of polyester. The underlay 14 is of foam anti-skid matting and has apertures therein and drop-shaped protrusions of cellular material on the lower surface which contact the drainage ground layer 8. The drainage layer 8 preferably includes square rubber granulate and polyurethane while the lower layer 10 contains coarser gravel and less rubber granulate for increased rigidity. The layers 8, 10 may lie directly on top of the subsoil layer or on a drained gravel ballast layer 6 extending between the concrete ribs 4. Heating elements 44 may be included to disperse water more rapidly. In an alternative embodiment of the fastening arrangement, the channel 20 has widened portions adjacent the base which accommodate locking rails (26) (Fig. 4 not shown) urged apart by inserted locking elements 22.