| 摘要 |
<p><PICT:0880236/IV (a)/1> <PICT:0880236/IV (a)/2> <PICT:0880236/IV (a)/3> A method of extruding thermoplastic nets comprises extruding a first set of circularly arranged parallel individual fibres 15, extruding a second set of circularly arranged parallel individual fibres 16 concentric with the first set and directing the sets of fibres along intersecting paths so that they fuse together to form a net 18. The fibres are extruded from dies 11, 13 having orifices 12, 14, and either or both dies may be arranged to rotate at varying speeds to produce different net patterns. The extruded fibres of one set may be of a different size or spacing from those of the other set. The fibres are passed over a mandrel 17 of a size as least as great as that of the outer set of fibres to fuse the fibres into the net. The net 18 may pass through a ring 22 into a heating bath 19 to be radially stretched by a mandrel 20 and/or axially stretched by rollers 21 to produce oriented net. The tubular net may be slit into a sheet. Details of materials, orientation and stabilization temperatures are given. More than one layer of nets may be extruded and combined into a rope.</p> |
