| 摘要 |
<p>A melt-embossed polymer film is provided on one surface with a set of parallel grooves and on the other surface with a second set of parallel grooves at an angle to the first, the combined tapes of the grooves being at least substantially equal to the thickness of the film. The ratio between the intersection area common to two ribs on different surfaces and the cross-sectional area of each rib is low, e.g. not greater than 2:1 to ensure transmission of orientation on subsequent stretching. The ribs between the grooves may be square, trapezoidal (provided that the included angle of the tapering sides is not greater than 45.degree.) or wider at its outer part than at its inner part. Ribs of these shapes, especially the last named, can be produced by using deformable, e.g. rubber, profiling means.</p> |
