| 摘要 |
The method finds application for making two-way stretched packing sheets out of polytetrafluoroethylene for the production of gaskets for chemical, petroleum and other industries. It secures identical thickness and density in each point of the sheet and identical physicochemical parameters in the two mutually perpendicular directions which guarantees a higher term of exploitation and of reliability of the produced gaskets. Typical for the method is the use of a flat bearing element which can have the form of a plate or of frame. The heat treatment of the made out of many layers and stretched in one direction polytetrafluoroethylene band (2), together with the bearing element (1 or 9), and their cooling down to room temperature is achieved by an incessant pressure upon the multilayer polytetrafluoroethylene band (2) with a load from 5 to 100 N/cm2 by means of smooth plates, parallel to the plane of the flat bearing element and separated by at least one spacer (7). |
