| 摘要 |
<p>The system for production of thermoplastic film bearing microengravings on both sides foresees of the following stages: impression of the microengravings on one side of the film by an embossing process performed on a first embossing unit at a first temperature and a first pressure falling within the range of temperatures and pressures normally used for embossing of film produced from said material, and impression of the microengravings on the other side of the film by a subsequent embossing process performed on a second embossing unit at a second temperature considerable lower than said first temperature and a second pressure considerably higher than said first pressure with said second temperature and pressure being chosen in such a manner that said subsequent process does not affect the microengravings impressed in the first process. <IMAGE></p> |
