process for the manufacture of tubular extruded plastic net, and device for implementing the process

摘要

957,749. Extruding netting. PLASTIC TEXTILE ACCESSORIES Ltd. Nov. 13, 1961 [Nov. 25, 1960], No. 40472/61. Heading B5A. [Also in Division D1] In the extrusion of tubular plastic netting composed of two adjacent layers of parallel strands in intersecting relation, the strands of a third layer which are parallel to the axis of the extruded tube are arranged to contact and adhere to the strands of at least the adjacent of the other two layers in intersecting relation thereto while the said two layers are still in the molten state. Intersecting diagonal strands 1, 2 (Fig. 2) are extruded through orifices 8, 7 in contra-rotating die members 10, 9 respectively, preformed filaments 3 being simultaneously introduced through a hollow shaft 11 and guided by rings 12, 13 to contact and bond with the strands 1 in their molten state prior to cooling in a water bath. The filaments 3 may be of plastic, cotton, glass or metal and may be of circular, square, oval or D-shaped cross-section as may be the strands 1, 2. Alternatively (Fig. 4) the filaments 3 may be extruded through orifices 17 in a fixed die member 14, formed with an annular groove 15 communicating with a cavity 6 for molten plastic via holes 16 in the member 10, and united with the strands 1, 2 over a cylindrical former 18. Alternatively, filaments 3 may be applied exteriorly and may be extruded from a different plastic supply. Specification 836,555 is referred to.