GB1349645A - Adhesive thread - Google Patents

Abstract

1349645 Coated products CPC (UNITED KINGDOM) Ltd 18 May 1971 [3 June 1970 22 March 1971] 15920/71 and 15921/71 Divided out of 1349644 Heading B2E [Also in Divisions B5 and Dl] An adhesive thread comprises (a) a core formed of natural or synthetic fibres having a denier of 50 to 3,000, preferably less than 1,000, e.g. 100-125, and a tenacity of at least 0.9 grams per denier at 65% relative humidity and 20‹C, and (b) a coating of hot-melt adhesive in an amount of from 0.02 to 2.00 grams per metre, preferably 0.05 to 0.50 grams per metre, the coating comprising a blend of film-forming polymer, a tackifying resin, and an antioxidant, the blend softening to a viscosity of below 500 poise at a temperature between 70‹C and 200‹C, preferably 100-150‹C, e.g. 120-130‹C. Specified materials for the core are polyester, polyamide, cotton, rayon, glass and wire. The film-forming polymer may be an ethylenevinyl acetate copolymer, a hydroxy-modified ethylene-vinyl acetate copolymer or a polyamide resin. Specified tackifiers are polyamides, hydrogenated rosin, rosin esters, polyterpene resins, alpha-methyl styrene/vinyl toluene copolymers, and chlorinated diphenyls. A suitable coating composition may comprise 15-50%, preferably 25-40% ethylene vinyl acetate copolymer, 0-20%, preferably 2-10%, wax; 35-65%, preferably 45-60%, tackifying resin; up to 5%, preferably 0.5-2%, anti-blocking agent; 0.1-2% antioxidant and up to 10% pigment or filler, the percentages being by weight. As shown, the hot-melt adhesive 10 is stored in granular form in a hopper 11 and fed by an extruder 12, driven by a motor 13. Six coated threads 14, withdrawn from spools 15, emerge through dies at 16. The coating is solidified by passage of the threads through a water-cooled heat exchanger 17 and the threads are wound on bobbins 18 on a six-station hydraulic winder 19.