Patent ID: 6612356
Filing Date: 2003-09-02
Classification: B29C,B29K,B29L,B32B,Y10T

Abstract:
An apparatus for longitudinally sealing a tube formed from polymeric plastic sheet film material, comprising a sealing die and a back-up plate between which layers of polymeric film pass for forming a seal between the film layers, the sealing die having a sealing face and the back-up plate having an anvil surface that opposes the sealing face of the die, the apparatus further including a back-up pad over the anvil surface of the back-up plate, the back-up pad having a slip layer and a polymeric support layer, the support layer being on the anvil surface of the back-up plate, the slip layer opposing the sealing face of the die so that said layers of film material pass between the sealing die and the back-up pad during seal formation, the polymeric support layer comprising a polymeric material with a Shore-A hardness of at least 10 at 20Â° C. and a dynamic loss tangent of less than 0.1 from 20Â° C. to 80Â° C.