초록 ▼

In order to produce a biaxially orientated mesh structure using a single axis draw, a plastics material starting material has parallel, side-by-side main zones separated by lines of holes or depressions; the starting material is drawn parallel to the main zones, stretching the main zones into contin

In order to produce a biaxially orientated mesh structure using a single axis draw, a plastics material starting material has parallel, side-by-side main zones separated by lines of holes or depressions; the starting material is drawn parallel to the main zones, stretching the main zones into continuous, orientated main strands 4 interconnected by smaller cross-section strands 6 which have been formed from the zones between holes or depressions in each line, and have been orientated at right angles to the direction of drawing by the effect of the main zones decreasing in width as they were stretched. The mesh structure is suitable for cross-lamination.

대표청구항 ▼

A method of making a plastics material mesh structure, comprising: providing a plastics starting material which has a regular pattern of holes or depressions, the holes or depressions being in parallel lines, the distance between the holes or depressions of one line and those of the adjacent line be

A method of making a plastics material mesh structure, comprising: providing a plastics starting material which has a regular pattern of holes or depressions, the holes or depressions being in parallel lines, the distance between the holes or depressions of one line and those of the adjacent line being substantially greater than the distance between the holes or depressions in each line, the holes or depressions defining elongate, side-by-side main zones between the lines of holes or depressions and intermediate zones between the holes or depressions in each line, each of which intermediate zones is generally symmetrical about a line at right angles to the line of holes or depressions, the major part of the thickness of each intermediate zone being between planes defined by the outer faces of the main zones; and drawing the starting material at a temperature above the glass transition temperature but low enough so that melt flow orientation is prevented, said drawing being only in a direction substantially parallel to the main zones while preventing substantial reduction of the pitch of the main zones though permitting reduction in width of each individual main zone, thereby stretching the main zones out into continuous, uniaxially-orientated main strands with the orientation therein extending substantially uniformly from end to end and generally parallel to the drawing direction, substantially decreasing the width of the main zones when forming the main strands, the distance between the holes or depressions of one line and those of the adjacent line being sufficiently greater than the distance between the holes or depressions in each line so that the force of contraction of each main strand as the main strand reduces in width causes said intermediate zones to stretch in a direction generally at right angles to the drawing direction to form discontinuous, uniaxially-orientated initerconnecting strands which interconnect the main strands, whereby a biaxially-orientated mesh structure is produced comprising said orientated main strands and said orientated interconnecting strands with the orientation in the interconnecting strands extending generally at right angles to the main strands and the cross-sectional area of the mid-points of the interconnecting strands being less than the minimum cross-sectional area of the main strands, and in which mesh structure there is adjacent each end of each interconnection strand a zone of plastics material which is thicker than the material of the remainder of the interconnecting strand.