GB955172A - A method and apparatus for sealing containers of synthetic plastic material - Google Patents

Abstract

955,172. Packaging; stoppers. N. HAGEN. April 13, 1961 [April 16, 1960], No. 13405/61. Headings B8C and B8T. A plastic container 10, Fig. 1, is sealed by a disc 17, having a lower layer of plastic and an upper layer of a material such as aluminium foil, punched out of a continuous composite strip 10 by a heated plunger 14 which also welds the disc in position. In Fig. 2, a plastic strip 41 is backed by a strip 40 of aluminium foil, paper, or " Cellophane " (Registered Trade Mark), and the two-layer strip passes through a heated embossing or printing device 18, Fig. 1, to a die 43 beneath which the containers are positioned by a conveyer. The plunger 48 is heated electrically and is reciprocated by a lever 61, Fig. 3, actuated by an hydraulic plunger 60 which is automatically controlled by a switch closed when a container 37 is in position. On the downward movement of the plunger 48 to punch out the disc and weld it in position, an arm 64 on lever 61 moves a pawl 69 over a ratchet 70 so that when the plunger returns, the spring-loaded pawl 69 rotates ratchet 70 and actuates a device 45 for advancing the strip 40, 41, step-by-step. The die 43 and plunger are carried by a frame 31 adjustable on slides 32 for use with different size containers. The backing piece of aluminium &c. may be removed from each disc 17 or may be left in position thereon. The end of the plunger 48 may be concave to prevent damaging the embossing on the disc and may be knurled to crimp the edge of the disc. The container neck may be screw-threaded for a protective cap for the disc 17.