Method of making apertured films and net like fabrics
AssigneeApplied Extrusion Technologies, Inc.
InventorsEdward E. Hovis, Eric D. Johnson
Life of this patent
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Abstract
A method of making apertured films including the step of perforating films of thermoplastic materials with embossing rolls engraved with patterns which form small slits or incipient slits in the sheet. The patterns are such that the design on the roll includes lands, or raised areas, which cross lands of the opposing roll at an acute angle. The perforated or partially perforated film formed may then be further processed by orientation, uniaxial or biaxial, simultaneous or sequential; by heat treatment; or both to modify the porosity, hole size, or other properties as desired.
Claims23
A process for the preparation of an apertured thermoplastic film comprising the steps of (a) extruding a molten thermoplastic polymer film between 0.5 and 20 mils thick;
- and (b) providing the extruded molten polymer film with a multiplicity of small slits by passing the film through the nip of two rollers engraved with patterns containing edges of lands such that the edges cross each other such that the angle formed by the crossing edges is between 15.degree. and 75.degree. with the slits being formed by the edges of the lands at their intersections cutting through the film and with the slits being arranged in patterns having from 10 to 150 slits per inch.
Dependencies are inferred from the claim text.