PROCESS FOR FORMING FILM

摘要

A method of making and using a stretchable film includes an extruding operation where molten plastics materials are extruded into a tube and a blowing operation in which the tube is blown to expand a diameter of the tube and form a blown-film tube. The blown-film tube is slit to form a film sheet that may be deformed elastically in a machine direction.

主权项

1. A method of making and using a stretchable film sheet, the method comprising the steps of
extruding a tube made of plastics materials including polyvinyl chloride, blowing the tube to establish a blown-film tube having a first temperature and a first length, heating the blown-film tube to provide a heated-film tube having a relatively greater second temperature, elongating the heated-film tube by applying force to the heated-film tube in a first direction to provide an oriented-film tube having a relatively greater second length, cooling the oriented-film tube to a third temperature to provide a cooled-film tube and the third temperature is less than the second temperature, slitting the cooled-film tube to provide a stretchable film sheet, and deforming elastically the stretchable film sheet in a second direction transverse to the first direction.