MANUFACTURE OF PIPE

摘要

PURPOSE:To extrude a long sized pipe having no blow hole by specifying the ratio A/B of the sectional area A of the leading-in path of an extrusion material to the surface area B of the abuttment engaging with an endless groove. CONSTITUTION:An extrusion is performed by taking as 1.05-1.5 the ratio A/B of the sectional area A of the lead-in path formed by the endless groove 2 on the peripheral face of the movable wheel 1 of a conform extruding machine and a fixed shoe block 3 to the surface area B of the abuttment 5 engaged with the groove 2. The air pulled in together with the extrusion stock is left in an sandwich shape between the outer periphery of the abuttment 5 and endless groove 2 and made so as not to approach into a container 6 by limitting this value. This part can be removed by a scraper 10 as a brush. Consequently the long sized pipe having no blowhole can be subjected to an extrusion.