METHOD OF FORMING COUPLING HEAD PORTIONS IN PRODUCTION OF SLIDE FASTENER COUPLING ELEMENT

摘要

In a method of forming coupling head portions on a monofilament of thermoplastic synthetic resin for production of a slide fastener coupling element, the monofilament is stamped from one side to form recessed small-thickness portions bulging from the other side of the monofilament, and then the monofilament is bent at opposite ends of each of the recessed smallthickness portions in such a manner that the concave side of each small-thickness portions faces outwardly.