Patent ID: 6358463
Filing Date: 2002-03-19
Classification: B29B,B29C,B29K,B29L

Abstract:
Method for the processing of tubes made of plastic, obtained by extrusion, according to which a tube is brought to a molecular orientation temperature higher than ambient temperature and is subjected to biaxial stretching by radial expansion and by axial elongation, in order to obtain a bi-orientation tube having improved mechanical properties, characterized in that:the tube (T) is cut into elements (4) of specific length when it has just been extruded and when its temperature is higher than the molecular orientation temperature, each element constituting a blank (5); each blank (5) is placed in an enclosure (E) in order to be cooled there by a fluid (F) at a temperature near the molecular orientation temperature, the dwell time of the blank in the enclosure being longer than the time for producing the blank by extrusion, in order to allow correct temperature setting, and the blank (5a) is subsequently extracted from the enclosure (E) in order to undergo the processing which ensures bi-orientation.