ES290076A1 - Method of and apparatus for producing reinforced plastic compound tubular material - Google Patents

Abstract

A method of producing stress-resisting tubular material from resinous matter consists in providing a homogeneous resinous core 10, applying on its outer surface evenly spaced longitudinal threads, winding helically over the first threads a plurality of second threads and embedding both layers of threads in a layer of cured resinous matter. Further layers of helically wound and/or longitudinal threads may be applied. The core tube 10 is of polyvinyl chloride, extruded at 30 (Fig. 4) and gauged and cooled at 31. The longitudinal threads are rovings of glass fibre 13 from spools at 34 and are wetted at 33 with a curable liquid polyester before being drawn through holes (Fig. 1, not shown) spaced circumferentially around a disc 32 on to the core tube at 101. More liquid polyester is added from a hopper 35 before a rotating annulus 17 winds glass fibre rovings from bobbins 18 helically over the longitudinal threads at 1011. Further liquid polyester may then be sprayed on to the assembled article before it is passed on rollers 38 through a polymerizing oven 39 and a cooling chamber 40. The tube is drawn through all the aforementioned apparatus by a motor-driven driving frame 41 after which a rotary cutter 43 divides it into lengths. By regulating the speed of a motor 37 driving the annulus 17 relative to the rate of draw it is possible to control the pitch and thickness of the helical winding. For coupling lengths of the pipe together by a sleeve or other known method the core at the ends of each length of tube may be left uncovered as in Fig. 3. This can be effected by placing sleeves over the core extending over the points where it is to be cut, winding the rovings over the sleeves, severing the pipe lengths at the middle of the said sleeves and cutting the remaining half-sleeves off the core (Fig. 2).