Apparatus for converting thermoplastic film into an open-work sheet

摘要

A two-dimensional integral net having a nap in form of relatively long fibres which are integral with the net and protrude from the edges which surround the apertures of the net. A method of producing this net from a film is by heating selected areas of the film to a molten state and dragging out this molten material into fibres to leave apertures in the film while controlling the fibre-dragging by cooling with an air jet.