PIPE MADE FROM COMPOSITE MATERIAL AND METHOD OF MANUFACTURE OF SUCH PIPE Russian patent published in 2002 - IPC

FIELD: manufacture of pipes. SUBSTANCE: sealing layer is made from thermosetting composite on base of polymer-oligomer system containing additionally plasticizer, filler, epoxy resin hardening initiating agents, viscosity controller, stabilizers and dye; composition includes the following components, parts by mass: polyvinyl chloride (o. 35-0.42); vinyl copolymer (0.05-0.08); epoxy resin (0.10-0.20); dicyanodiamide (0.010-0.020); dioctyl phthalate (0.10-0.20); talc (0.10-0.20); calcium stearate (0.005-0.015); aerosil (0.003-0.008) stack consisting of three adhesion layers, from 1.4 to 3.5 mm in thickness formed between load-bearing framework and inner sealing layer is made from chemically and abrasive-resistant material - thermosetting composite on base of polymer-oligomer systems; layer are wound of sealing layer in the following succession: double spiral layer of roving at angle of winding relative to longitudinal axis from 52 to 57 deg. at thickness of up to 0.7 mm and two layers of nonwoven impregnated cloth; load-bearing framework is made in form of pack including 2 to double spiral layers' ends of pipe are provided with connecting members at simultaneous winding of sealing layer and load-bearing framework. Sealing layer is formed by winding the tape from chemically-resistant thermosetting composite on base of polymer- oligomer system, 0.6 to 0.8 mm thick on mandrel coated preliminarily with layer of anti-adhesion material at pitch equal to width of tape; then, second layer of tape made from same material is wound on first layer at shift of 0.5 pitch, after which 3rd layer of thermosetting composite of base of polymer-oligomer system is wound winding is from opposite end mandrel; then, three adhesion layers are wound on pack; pack includes successive winding of double spiral layer up to 0.7 mm in thickness which is made from glass or basalt roving at angle of winding from 52 to 57 deg. followed by winding of two layers of non-woven material impregnated with binder; then, load-bearing framework is formed by winding 2 to 20 double spiral layers of roving at tension force of 0.4 to 2.0 kg per mm of roving, after which connecting members are formed at ends of pipe. EFFECT: enhanced strength and reliability of pipes. 13 cl, 8 dwg