| 摘要 |
991,465. Seaming non-metallic sheet. PROCTER & GAMBLE Ltd. Oct. 16, 1961, No. 37075/61. Heading B5K. [Also in Division B8] A process for sealing two thermoplastic, water-soluble, moisture containing films 15, 22 comprises leading the films together to form a nip, directing - a gas comprising superheated steam against at least one film to soften it and automatically control its moisture content, and pressing the films together. A film 15 which may be moistened at 18 and passed beneath a heated roller 17 is applied to the surface of a driven drum 1 provided with pockets surrounded by lands preferably covered with a rubbery material to increase the adhesion of the film thereto. Belts (not shown) hold the film edges in contact with the drum during the formation and filling of pockets formed in the film (see Division B8). A second water-soluble film 22 is applied by a roll 24 to overlie the filled pockets. Super-heated steam from a manifold 25 is directed into the nip between the roll 24 and the drum 1 and the films sealed. Steam is fed to a manifold 27, Fig. 3, provided with a heater 28. The super-heated steam then passes through a valve 30, which lowers the pressure thereof to approximately atmospheric, to the manifold 25 having nozzles 32 through which the steam issues in a cloud at low pressure. A slot-shaped orifice may replace the nozzles 32. An additional manifold 34 may heat the film as it passes around the roller 24. Specifications 991,464 and 991,466 are referred to. |
