PROCEDE DE FABRICATION DE TUBES EN MATERIAUX THERMOPLASTIQUES RENFORCES PAR DES FIBRES A ORIENTATION CONTROLEE ET APPAREILLAGE POUR SA MISE EN ÓOEUVRE.

摘要

Tubes (pipes) made from fibre-reinforced thermoplastic materials are manufactured by a method for extruding the thermoplastic material into a die having a diverging terminal zone, the terminal zone of which includes a diverging annular flow space which has a ratio As/Ae between the exit area and the inlet area of at least 1.2 and a ratio between the length l of the annular exit space of the diverging zone and the width e of the cross-section of the said annular space less than 5, the extrusion being carried out in the presence of a liquid lubricant which is not compatible with the said thermoplastic material at the extrusion temperatures, the said lubricant being present in the region of the outer wall and in the region of the inner wall of the said flow space. …The tubes (pipes) manufactured by this method have an especially high burst strength and an improved surface state. ……