| 摘要 |
<p>1992 Mar 20 DC-3084 A heat sealing assembly, for sealing through at least two layers of thermoplastic film is disclosed. It is particularly adapted for use with a vertical form, fill and seal machine for packaging flowable materials. The heat sealing assembly comprises two jaws (11 and 12), resilient clamping elements (14, 15, 16 and 17) and a heat sealing element (20), at least one of the jaws being capable of transverse motion and adapted to collapse a tubular film made from the thermoplastic film and passing between the jaws, each of said jaws having said element mounted thereon, said clamping elements being adapted to grip thermoplastic film which passes therebetween and urge said gripped film towards said jaws when the jaws close and to release said film when the jaws open. Clamping is accomplished without an activating device other than the jaws themselves. Preferably there are clamping elements on both sides of the jaws. Preferably the clamping elements are made of a flexible rubber. DC-3084</p> |
