TEXTILE-LIKE APERTURED PLASTIC FILMS.

摘要

Stretchable thermoplastic film (30) has micro-holes (37) defined by network of fibre-like elements (38). Pref. the apertured film is made by directing fluid at its upper surface in the form of columnar streams. Pref. the fibre-like elements defining the holes have been drawn at least 100 percent as compared to adjacent regions of the film. The micro-holes are 3 x 10 power -10 - 4 x 10 power -5 inch in area and they may be provided in patterns of distinct groups or randomly distributed and irregular in shape, their coefficient of variation of shape factor being at least 25 percent. They have equivalent hydrqulic dia. of 0.0005-0.025 inch with coefft. of variation of at least 50 percent. The film has open area of 1-15 percent provided by the micro-holes. The fibre-like elements are 0.005-0.05 inch long, 0.001-0.035 inch wide, and 0.000025-0.002 inch thick. The film may have secondary openings of larger area than the micro-holes. The film most pref. has a series of parallel ridges (32) sepd. by valleys (33), the microholes being confined to the valleys including the lower reaches of the angled side walls. The ridges have a sinusoidal configuration. The micro-holes are arranged in clusters or rows separated by unapertured film.