| 摘要 |
The process is intended for treating thermoplastic webs after production and/or storage and involves passing the web through a preheating zone at the temperature t1, then through a heating zone at the temperatures t2 and t3 and subsequently through a cooling zone at the temperature t4, the temperature conditions being set such that t1 </= t2 and t3; t3 >/= t2 and t4 </= t2 and t3, where t2 and t3 are close to (+/- 10 DEG C) the softening point tg of the web material for the reduction of inequalities and t3 is kept 20 to 70 DEG C >/= t2 for the dimensional stabilisation and the web is kept in the heating zone t2, t3 for 1 to 30 seconds. The invention also relates to various apparatuses for carrying out the process, which contain a preheating roll and separate heating and cooling devices. <IMAGE> |
