| 摘要 |
<p>PURPOSE:To provide the manufacturing method for a synthetic resin tube which can even sense micropores with high sensitivity by passing a tubular synthetic resin extruded from an extruder while the outer face of tubular synthetic resin is brought into contact with the inner face of a vacuum molding jig by vacuumizing and sensing the variation of the degree of pressure decrease inside the vacuum molding jig. CONSTITUTION:The volume inside a separate tank 46 is remarkably larger compared with the air leakage amount through micropores, and the degree of pressure decrease in the separate tank 46 is scarcely varied and the indication of a vacuum gauge 48 is almost standstill. The volume inside a ring channel 42 of a sizing jig 4 is small compared with the air leakage amount through said pores, and the tubular synthetic resin is in the heat softened state and the pores are enlarged by the differential pressure to increase the air leakage amount, and the variation of degree of pressure decrease in the ring channel 42 is remakable. A pressure sensor 7 directly connected with the ring channel 42, therefore, can be operated at high sensitivity to sense even micropores in a highly sensitive manner.</p> |
