METHOD OF MAKING SAFETY PARTS FOR TUBE END INNER AND OUTER SURFACE PROTECTION Russian patent published in 2012 - IPC B29C45/02 B29C45/72 B29D23/00 F16L57/00 

FIELD: process engineering.

SUBSTANCE: invention relates to production of tubes, particularly, to making parts to protect tube inner and outer ends including threadless and threaded ends of oil standard tubes. Proposed method comprises moulding polymer case by injecting fused material into moulding tool arranged in horizontal injection moulding machine. Polymer composition used herein consists of LPPE ≤50.0%; PHPE ≤50.0%; SPEVA ≤8.0%; activator ≤1.0%, with softening point not lower 80°C; brittle temperature not exceeding - 65°C; specific resilience, at least 2.0 J/cm² and thermal expansion factor corresponding to that of protected tube material. Polymer material is fused in injection moulding machine plasticator cylinder with temperature distributed over four heating zones: 1^st zone: 120-160°C; 2^nd zone: 150-200°C; 3^rd zone: 150-200°C; 4^th zone: 120-160°C. Then, it is cooled in mould for 20-90 s. Mould opening area is perpendicular to mould clamping force direction. Said mould is furnished with cold-channel gating system using water coolant at the pressure of, at least, 2 MPa and pressure difference at mould inlet and outlet making 8-10°C. Cooling channel diameter makes 8-20 mm.

EFFECT: high-efficiency polymer protective part.

2 cl