摘要 |
FIELD: rubber industry; public services; water and sewage pipe lines. SUBSTANCE: proposed method consists in layer- by-layer assembly of envelope from covering and sealing material at stage-by-stage vulcanization; first, envelope is assembled in developed form and partial vulcanization is performed in mold, for example; then envelope is withdrawn from mold, folded along longitudinal axis forming several layers, fixed and subjected to final vulcanization mainly in vulcanizing kettle. EFFECT: improved quality; increased productivity. 2 cl, 9 dwg |