| 摘要 |
<p>A tube has its walls made up from layers of fibrous sheets impregnated with a thermoplastic (I). Pref. the (I) impregnated sheets are wound, at a temp. > m.pt. of (I), around an internal former as one or more overlapping layers, then compressed at 5-300N/cm using a tension tape made of heat-stable films. Opt. a preformed strip of hard foam is introduced between the layers and an endless glass fibre may be wound on simultaneously. The tubes are made quickly and easily and have good and uniform qualities esp. strength. Typical plastics are polyethylene, polypropylene, styrene (co)polymers, PVC etc, and the fabric is e.g. a mat, fleece, or web of glass-, C- plastics or asbestos-fibres coated with usual polymeric binders.</p> |
