Abstract: In order to provide wider biaxially-stretched geogrids having high primary direction (PD) strength, crotch-forming zones of a starting material which is at least 2.0 mm thick have protuberances (6). On strectching, PD orientation passes right through the junction (27) but the protuberance (6) causes the orientation ratio of the crotch edge to decrease significiantly as orientation enters the central part of the crotch edge. After a secondary direction stretch of at least about 1.5:1, the thickness of the central part of the crotch edge is not reduced by more than about 20%. The stretching does not reduce the thickness of any point along notional ridge lines (31) to such an extent that the ratio of finished thickness to starting thickness at that point mid-point. In the biax geogrid (25), the junction mid-point is significantly thicker than the PD is less than about 80% of the ratio of finished thickness to starting thickness of the junction strand mid-point.

Abstract: An extruded plastic mesh of the type indicated having mesh openings each of which is a six-sided figure bounded on four sides by portions of four separate strands and on oppositely disposed two sides by elongate members comprising confluent portions of pairs of said four strands and forming a crotch at each end of each elongate member, wherein all of said strands and elongate members have preferred molecular orientation of the plastic material thereof in the direction of their major dimension and passing through and around the crotches of the elongate members of adjacent mesh openings and wherein the length of each elongate member measured from crotch to crotch is at least twice the diameter of a notional circle having the same area as the cross section of the elongate member at about its mid-point.