| 摘要 |
Thermoplastic films with improved mechanical and physicochemical properties are manufactured in such a manner that the film, in one operating step, is heated for a short time (e.g. 1 to 10 seconds), under tension (which causes an elongation of at least 25%) and orientation, to the thermoplastic temperature of the plastic material used and subsequently subjected to further orientation by deformation within the range of its thermo-elastic temperature or its crystalline melting point. PVC film (K value above 65) is formed e.g. at a temperature below 180.degree.C and subsequently heated, under stretching and orientation, to at least 200.degree.C. An apparatus for carrying out the process is also described. |
