| 摘要 |
<p>PROBLEM TO BE SOLVED: To form a linear synthetic resin molded body, in which both a long linear synthetic resin-molding part having a large section and a synthetic resin- molding part having a small section are provided successively via a connection part abruptly formed into a small diameter capable of substantially neglecting its length in comparison with the length of these resin-molding parts. SOLUTION: A linear synthetic resin-molding part having a large section is extruded in a prescribed length by an extruder. Thereafter, the inside of a cylinder is suddenly evacuated by stopping or reversely rotating the rotation of a screw in a cylinder of the extruder by a short time not exceeding several seconds. Thereby, the part following the linear synthetic resin-molding part having the large section is formed into a connection part, in which length is extremely short and a section is abruptly shrunck. Thereafter, the screw is immediately rotated at velocity slower than a time for forming the synthetic resin-molding part having the large section and the shape of the minimum section in the connection part is continued in the direction of length as it is and thereby a synthetic resin-molding part having a small section is molded.</p> |
