| 摘要 |
In prodn. of biaxially stretched thermoplastic synthetic material sheets of thickness below 3 microns where at least two sheets with one on top of the other are stretched together in the length and breadth directions, a carrier layer and at least one covering layer are prepd. on respective take down rollers, at least one surface of the carrier layer or the covering layer is treated with an electrical corona discharge, and the carrier layer and the covering layer are brought together such that the corona-discharge-treated layer lies between the two layers. - A thin polyester covering layer is pref. brought onto a polyolefin carrier layer. The electrical corona discharge is pref. achieved using emitting electrodes which are connected to a high frequency generator, where the treatment is carried-out such taht the corona-treated surface exhibits, after treatment, a surface potential of at least 40 mN/m. The polyester foil is prepd. at a thickness of 0.5-3 microns, esp. 1-2 microns. |
