Artificial turf having fibers with different melting points

Abstract

An artificial turf system is for installation over a receiving surface. The artificial turf system comprises a flexible sheet member to be laid over the receiving surface via its lower surface. It comprises first yarns having a first melting point; second yarns, distinct from the first yarns and having a second melting point; and third yarns, having a third melting point, with all yarns extending upwardly from the upper surface of the sheet member. The third melting point is lower than the first and second melting point. The artificial turf system undergoes a heat treatment at a temperature higher that the third melting point prior to installation through which third yarns at least partially fuse with part of one of the first yarns and the second yarns. Further described is a method of manufacturing the artificial turf system.

1 . An artificial turf for installation over a receiving surface, the artificial turf comprising:
 a sheet member made of a flexible material, the sheet member comprising a lower surface to be laid over the receiving surface and an upper surface;   first yarns having a first melting point, the first yarns extending upwardly from the upper surface of the sheet member;   second yarns distinct from the first yarns and having a second melting point, the second yarns extending upwardly from the upper surface; and   third yarns distinct from the first yarns and the second yarns and having a third melting point, the third yarns extending upwardly from the upper surface,   wherein the third melting point is lower than the first melting point and the second melting point, and   wherein, after the artificial turf has undergone a heat treatment at a temperature higher that the third melting point, the third yarns are at least partially fused with at least part of one of the first yarns and of the second yarns.   
     
     
         2 . The artificial turf of  claim 1 , wherein one of the first yarns and the second yarns are made of straight fibers. 
     
     
         3 . The artificial turf system of  claim 2 , wherein, after having undergone the heat treatment, the yarns made of straight fibers extend upwardly beyond the other yarns. 
     
     
         4 . The artificial turf of  claim 1 , wherein one of the first yarns and the second yarns are made of one of textured fibers and thatch fibers and are not straight fibers. 
     
     
         5 . The artificial turf of  claim 1 , wherein one of the first yarns and the second yarns are made of polyamide. 
     
     
         6 . The artificial turf of  claim 1 , wherein the third yarns are made of olefin material, comprising one of polyethylene, polypropylene, polyester (PET), and a combination of polyethylene and polypropylene. 
     
     
         7 . The artificial turf of  claim 1 , wherein the first yarns, the second yarns and the third yarns are backstitched to the sheet member according to parallel backstitches. 
     
     
         8 . The artificial turf of  claim 7 , wherein the backstitches are equidistant. 
     
     
         9 . The artificial turf of  claim 1 , wherein the second yarns and the third yarns are combined into combined yarns and backstitched together to the sheet member. 
     
     
         10 . The artificial turf of  claim 1 , wherein the first yarns comprise one of flat face fibers, monofilament fibers, monotape yarns, fibrillated yarns, polyfilament fibers, parallel fibrillated or fibrillated fibers, and split fibers. 
     
     
         11 . The artificial turf of  claim 1 , wherein the first yarns have a cross section that has a shape of one of a rectangular cross-section ribbon, a diamond, a horseshoe, a U shape, a V shape, an S shape and a flat rectangular general cross section with its shorter sides rounded. 
     
     
         12 . The artificial turf of  claim 1 , wherein the first yarns are straight, the second yarns are textured or thatch, and wherein the first yarns extend beyond the seconds yarns relative to the upper surface of the sheet member. 
     
     
         13 . The artificial turf of  claim 12 , wherein the second yarns are more rigid than the first yarns. 
     
     
         14 . The artificial turf of  claim 1 , wherein the second yarns are made of a plurality of filiform formations arranged in tufts. 
     
     
         15 . The artificial turf of  claim 1 , wherein the first yarns have a first length, the second yarns have a second length at least equal to the first length, the first yarns extend to a first elevation from the upper surface, and the second yarns extend to a second elevation from the upper surface lower than the first elevation. 
     
     
         16 . The artificial turf of  claim 1 , wherein at least one of the first yarns, the second yarns and the third yarns is backstitched as tufts with the tufts having a tufting gauge between three sixteenth of an inch ( 3/16″) and three quarter of an inch (¾″). 
     
     
         17 . A method of manufacturing an artificial turf, comprising:
 stitching to a sheet member (1) first yarns having a first melting point, (2) second yarns distinct from the first yarns and having a second melting point, and (3) third yarns distinct from the first yarns and the second yarns and having a third melting point lower than the first melting point and the second melting point, wherein the first yarns, the second yarns and the third yarns extend upwardly from the sheet member;   submitting the artificial turf to a heat treatment at a temperature equal to or above the third melting point but under the first melting point and the second melting point, whereby the third yarns at least partially fuses with at least one of the first yarns and the second yarns.   
     
     
         18 . The method of  claim 17 , further comprising maintaining the heat treatment between 2 seconds and 10 seconds. 
     
     
         19 . The method of  claim 17 , further comprising performing the heat treatment with a heat source of a temperature of between 125 and 225 degrees Celsius. 
     
     
         20 . The method of  claim 17 , wherein submitting the artificial turf to a heat treatment comprises having the yarns face a heat source.