Method of manufacturing separable slide fastener

A method of manufacturing individual slide fasteners of a separable type from a pair of continuous slide fastener stringers having a pair of stringer tapes carrying on one surface thereof a pair of interengaged rows of coupling elements along their opposed longitudinal edges, comprising the steps of:

• (a) feeding the continuous slide fastener stringers intermittently for a distance corresponding to a desired fastener length;
• (b) placing a backing strip of synthetic resin only on the other surface of the stringer tapes on which no coupling elements are carried while the stringers are held stationary between each intermittent movement, said strip extending transversely of the stringers at a first portion thereof;
• (c) placing a film of synthetic resin on said one surface of the stringer tapes on which the coupling elements are carried such that the film extends across and over a group of coupling elements at a second portion of the stringers adjacent to said first portion;
• (d) applying heat and pressure to the stringers at said first portion to fuse adjacent coupling elements with each other, the coupling elements with the stringer tapes on said one surface, and the latter with the strip on said other surface, and to shape the fused coupling elements under pressure into a predetermined configuration including a pair of reduced-thickness edge portions transversely spaced from each other and a major central portion disposed between said edge portions and in alignment with the interengaged rows of coupling elements, ready for the formation of a separable pin and a retainer pin, and at said second portion to fuse adjacent coupling elements with each other, the coupling elements with the stringer tapes, and the film with the coupling elements and the stringer tapes, and to shape the fused coupling elements and the film into a predetermined configuration ready for the formation of a pair of top end stop lugs;
• (e) cutting such fused and shaped coupling elements at said first portion so as to bisect said major central portion into the separable pin and the retainer pin, and at said second portion so as to finish the top end stop lugs;
• (f) simultaneously with said cutting step (e), cutting the stringers along a line extending transversely across the stringers and passing near one end of the two pins, whereby said continuous slide fastener stringers are severed into an individual slide fastener length;
• (g) threading a slider through one of the stringers of said individual fastener length on which the retainer pin has been formed;
• and
• (h) attaching a retainer to the retainer pin.