METHOD FOR MANUFACTURE OF ARTICLES FROM POLYMERIC MATERIALS Russian patent published in 2001 - IPC

FIELD: physico- mechanical and thermoplastic action on tubular blanks made of polyethylene materials, applicable in production of various domestic and industrial articles. SUBSTANCE: the method consists in production of a tubular blank by loading of material, heating of it and screw extrusion through an extrusion head. For production of a tubular blank use is made of preliminarily selected waste of polyethylene with a dispersity of 2 to 5 g. The quantity of introduced waste does not exceed 30% of the total mass of the produced blank. The rate of heating of the material fed by the screw conveyor is maintained within 12 to 14 C/s during 10 seconds, the speed of screw rotation being within 20 to 35 rpm. The tubular blank is fed to the mould of the vacuum-blow machine. For blow of the heated blank air is fed through the vacuum-blow mandrel. In the process of blow the air pressure is maintained within 0.5 to 2.5 MPa increasing the process temperature by 30 to 60 C. At the same time the maximum temperature of the process of material heating in the mould is automatically fixed within 180 to 200 C within a stand duration from 35 to 40 s. The blank is cut off, the mould is subjected to forced cooling, then it is disconnected and the molded blank is pushed out. Then the blank is fed for subsequent final processing of the external geometric profile. EFFECT: enhanced economical efficiency of the process. 4 dwg