| 摘要 |
PURPOSE:To manufacture readily an extruded tube of which a check valve operates certainly, by injection molding a mouth part having a valve body and a preform of a valve seat integrally to a body part, then, shaping the valve seat by sliding a mold and bending the preform of the valve seat inward. CONSTITUTION:After a beforehand molded body part is placed in a mold, a mouth part 10 having a valve body 15, a preform 20' of a valve seat is molded by injecting a synthetic resin in a mold cavity. Then, before the preform 20' of the valve seat solidifies perfectly, the valve seat 20 is shaped by lowering a mold 24, raising a mold 25 and bending the preform 20' of the valve seat inward. In such a way an extruded tube of which a check valve operates certainly can be manufactured simply and at a low cost. |
