摘要 |
The rods used are molecularly-orientated and of high tensile strength. They are laid in a single layer. Welding takes place cyclically, at successive adjacent crossing locations, using vibro-welding technology (friction welding). An Independent claim is included for the grid or mesh so produced. The vibro-welding system is also claimed Preferred features: 500-8000 intersections are welded simultaneously. Vibro-welders are operated simultaneously, applying uniform mechanical pressure, with the same amplitude (0.5-2.5 mm, preferably 1-2 mm) and oscillation frequency (60-300 Hz, preferably 150-180 Hz). Mutually-parallel rods run across the direction of feed (transverse rods). Others run parallel to each other and the feed (longitudinal rods). Their intersections are at 45 degrees to 90 degrees . Spacings side to side, are 10-100 mm, preferably 20-80 mm. Rods are located in numbers suitable to make grid or mesh 3-6 m wide, preferably 5 m wide. Total length is 25-500 m, preferably 50-100 m. Tensile strength is 300-800 N/mm<2>. Dimensions are quoted for square or rectangular rod cross sections, their sides ranging from 1 mm up to as much as 40 mm. Rods employed have embossments (to 0.5%-30% of their thickness) on top and/or underneath, for keying. Longitudinal rods are wider and/or thicker than transverse rods. In addition, fleece, fabric, knit or sheet is welded to one or both sides, using a hot iron, hot air or adhesive. |