| 摘要 |
<p>PCT No. PCT/GB93/00177 Sec. 371 Date Jun. 16, 1994 Sec. 102(e) Date Jun. 16, 1994 PCT Filed Jan. 28, 1993 PCT Pub. No. WO93/14928 PCT Pub. Date Aug. 5, 1993A cross-laminate of two or more individually stretch oriented films where the directions of orientation of the films are in criss-crossing relation, has a pattern of generally parallel elongated ribs extending lengthwise of the laminate. The ribs are defined between generally transversely coincident convex and concave curved surfaces on opposite faces of the laminate, the concave surface having a radius of curvature greater than that of the convex surface so that the ribs have a thickness greater than the average thickness of the laminate. The laminate material adjacent to lateral boundaries of the ribs is in a tensionless state reversely curved relative to the rib curvature making the material between adjacent pairs of ribs generally flat. The rib pattern is preferably regular with a preferred average transverse spacing between adjacent ribs, measured peak to peak, of about 1-10 mm. The convex surfaces of the ribs can all be on the same side of the laminate or can alternate in series between opposite sides. The pattern of elongated ribs can be interrupted at longitudinally spaced loci to enhance the flexibility of the laminate and the laminate can have an undulating curvature when viewed from the side. A process and apparatus for making the ribbed cross-laminate by means of intermeshing grooved rollers are also disclosed.</p> |
