| 摘要 |
Working up and utilising thermoplastic film, and more especially scrap film, in which the material to be treated, e.g. continuous strips, pieces, off-cuts or the like, is passed via a special feed device (7) between upper and lower work tools (3) and (4), and whilst simultaneously heating, the film is stretched so that it is permanently deformed and to such an extent that corrugations at least of the edges and subsequent bursting of these corrugations appears, and so that due to the very large increase in surface the density ratio (d) is 0.75 - 0.002 where d = gamma/gamma o and gamma,gamma o are respectively the apparent and true densities in g/cm3 of the material after treatment. The product leaving the stretching deforming device (3) (4) is cut up transversely and is taken via a conveyor either to storage or directly to a process for its utilisation e.g. formation of laminates for insulating purposes. The preferred stretching tool is a pair of rolls with adjustable gap and which have alternate regions of serrations or teetch in the axial direction on their peripheral surface. The necessary heating may be derived from the mechanical work carried out on the thermoplastic film, supplemented where necessary by infra-red or hot air heating and/or heated rolls.
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