GB541786A - Improvements in or relating to the manufacture of sliding clasp fasteners - Google Patents

Abstract

541,786. Sliding-clasp fasteners. LIGHTNING FASTENERS, Ltd. (Talon, Inc.). June 10, 1940, No. 10081. [Class 44] Sliding-clasp fasteners having non-metallic fastener members formed integral with the stringer tape are produced by treating the central portion of the tape with non-metallic material in liquid or plastic form, stamping out the treated portion to produce a ladder-like product, Fig. 2, and folding as in Fig. 4 so that the marginal portions 14, 15 of the tape are superposed, and the obliquely disposed folded portions 8, when consolidated, form projections which engage in recesses left between parts 11, 12. The finished members on a pair of tapes interlock as in Fig. 9 under the action of the usual slider (not shown) which co-operates with beadings provided on the tapes as, for example, by rolled portions 29 of the tapes secured by stitching, with or Without cord insertions 31. The ladder-like product may be provided with projections 22, Fig. 6, and recesses 23 which give interlocking projections and recesses in the finished product without the oblique disposition of the folded portion 8 shown in Fig. 4. As a modification, the central portion of the tape may be cut in zig-zag manner to provide comb-like lengths, the teeth being folded as above described to produce the fastener members. The Specification gives cellulosic compositions, compositions based on linear polymers or interpolymers comprising polyamides and polysulphonamides, vinyl resins, and polymers of ethylene as suitable materials, and particularly describes the use of a condensation product of phenol and formaldehyde, having an initial soluble state allowing application in liquid form, an intermediate partly polymerized state allowing stamping and working, and a final hardened, completely polymerized state unaffected by heat and solvents, the changes of state being effected by heat.