| 摘要 |
Polymer fleeces with a definite pattern of molecularly oriented parts are produced from an extruded, flat uninterrupted stream of liquid film-forming material by (a) pressing definite, spaced apart areas of the extruded flat stream, which lie in one line in the lengthwise and transverse directions and have the same shape, out of the surface of the extruded flat stream, without interrupting the continuity of the stream, and while the material is still in a liquid state, (b) fixing the stream to form a self supporting fleece, and (c) drawing the fleece in biaxial directions, so that the areas of the fleece between adjoining transverse inline areas are uniaxially oriented in the transverse direction of the fleece, the areas of the fleece are uniaxially oriented in the lengthwise direction of the fleece, and at least same of the remaining areas of the fleece are biaxially oriented. The process provides polymer fleeces with a high strength, stiffness and tear resistance from the thermoplastic polymer materials. |
