| 摘要 |
1313448 Film quenching apparatus E I DU PONT DE NEMOURS & CO 12 Nov 1971 [12 Nov 1970] 52689/71 Heading B5B In a process for producing quenched films of synthetic organic polymers molten polymer 2 is extruded from a die 1 on to the surface of an internally cooled casting drum 4 and is passed successively through a blast of cooling gas from plenum chamber 6; between a nip formed between calender roll 3 and drum 4, through another blast of cooling gas from a second plenum chamber (8); through a nip formed between a chilling roll 10, which dips into cooling tank 7 and is dried prior to contact with the film by air knife 11, and casting drum 4; and into cooling tank 7 which contains a liquid coolant, the cooled film being surface-dried by air knife 12; and by gas from a third plenum chamber 6 prior to being stripped from the casting drum by stripping roll 5. As illustrated the liquid coolant is preferably agitated in the quenching tank by being continuously recycled through lateral conduits 14, manifold 13 and the tank overflow system. Preferred cooling liquids are water and a water-ethylene glycol mixture. Examples relate to the production of haze-free polyethylene terephthalate films. |
