Heat-sealed thermo plastic-products and method and apparatus for manufacturing same

摘要

902,769. Seaming, non-metallic sheet material; laminates and laminating. BLEIWARENFABRIK GUMPOLDSKIRCHEN A.G. March 11, 1960 [March 12, 1959; March 23, 1959; Dec. 14, 1959], No. 8739/60. Classes 42 (1) and 140. A method of heat-sealing thermoplastic members comprises heating at least one metallic means to a heat-sealing temperature which is at least equal to the softening temperature of the plastic members to be heat-sealed, then inserting said metallic means while at said heatsealing temperature between the plastic members and compressing the plastic members and the inserted metallic means to bond them together. For heat-sealing two plates 1 and 11 of polyethylene or polypropylene lying in the same plane, with a butt joint, they are engaged at the edges 8 and are superimposed with a perforated metal strip 5 heated to the liquefying temperature of the plastic and with a further plastic strip 6, whereafter the parts are pressed together. The metal used may be iron, steel, brass, lead, copper, or aluminium, and may be in the form of bars, wires, wire fabric, or perforated or expanded sheet. The invention may also be used to join flanged members together to form a container and for making reinforced plastic panels. In the latter application (Fig. 11), two plastic webs or plates 41, 411, e.g. of polyethylene or polypropylene are withdrawn from supply rolls and fed between guide rollers 42, 421 to a preferably thermostatcontrolled preheating device 43 or 431. At the same time a perforated metal web 44 of steel, aluminium &c. is fed between the rolls 41, 411 by means of pairs of rollers 45, 451 to a heating device 46 which heats the metal web to a temperature somewhat above the liquefying temperature of the plastic. The two plastic webs with the metal web therebetween are then fed to the nip between pressure rollers 49, 491 where the webs 42, 421 liquefy, at least in the zones which adjoin the metal web 44, so that a reinforced plastic web emerges. The web is cooled by air or water sprayers 50 and is passed through pairs of rolls 52, 521 which smooth the surface of the web. In a further embodiment, reinforced plastic tube lengths are produced by applying plastic webs to both sides of a metal web in the form of a tube.