GB1417112A - - Google Patents

Abstract

1417112 Extruded netting NETLON Ltd 1 Dec 1972 [7 Dec 1971] 56788/71 Heading B5A Apparatus for extruding an integral plastics net comprises a pair of circular concentric, relatively rotating inner and outer die members 1, 2 each of which has a series of extrusion die slots A and a series of extrusion die bores B' The net produced may have mesh members comprising a first set of spaced parallel strands and a second set of spaced parallel strands extending transversely thereto wherein each set of strands comprises strands of dissimilar cross-section, the sets of strands being joined together at all or certain of their points of crossing to form a net structure and wherein (1) the crossing points along any one strand of the first set comprise (a) integral junction masses of mirror image symmetry about the median plane of the net intersections, e.g. see A/A of the key in Fig. 15, and (b) assymetrical junctions in which there is only linear contact and adhesion between the strands, e.g. A/B or B/A and (2) the crossing points along any of the strands of the second set comprise the latter form (b) above and (c) symmetrical junctions having only linear contact and adhesion between the strands or crossings with no adhesion between the strands, e.g. B/B. By positioning a slot and bore of a respective die member sufficiently close together each mesh member may comprise a dual strand which although is formed of two contiguous or coalesced strands is such that the separate identities of the component strands can still be discerned. A crossing point of a pair of dual strands produces four intersection points, i.e. A/A; A/B; B/A; B/B see Figs. 17, 18, not shown. The bores B may have a circular or rectangular cross-section. In the latter case the member 1 or 2 may be formed of two parts. The strands of the netting may be orientated by stretching. Various types of series of slots and bores are disclosed (see Figs. 7-9, not shown).