| 摘要 |
<p>Uniformly arranged reinforcing fibres are present in an endless polymeric drafting apron. The apron is made by winding a fibre-reinforced polymer ribbon with the fibres parallel to the length of the apron, or in crossing sets of parallel fibres, e.g. by helical winding. The lines between the layers, cooled, ground and cut to width. Alternatively, the apron is made by extrusion followed by rapidly stretching whilst the polymer is still molten. The polymer is nitrile rubber, the fibres are wood cellulose fibres 1-9 mm long, with an elastic modulis of 2-5 x 106 psi and a tensile strength of 6-9 x 104 psi.</p> |
