| 摘要 |
PURPOSE:To prevent sticking of the useless formation substancs to the inner face of the tubular product, by installing the bar protruding from the tip of the inner die of the circular die being set in the vicinity of the resin delivery slit. CONSTITUTION:The plural bar like objects of 5-30mm. length are protruded at the tip part of the inner die 5 of the die body 1 aparted less than 3mm. from the resin delivery circular slit 2 of the die (mark 4 is air introducing hole). When the tubular object 6 is formed by melt-extrusion of thermoplastic resin from the circular die, the useless formation substances (so-called eye secretion) condensed at the inner periphery of the delivery slit 2 stick successively to the bar like object 3 and is held by arranging the bar like object 3 in said manner. Therefore, sticking of the useless formation substances to the inner face of the tubular object 6 is prevented and a high quality product is obtained. |
