MANUFACTURE OF TUBULAR FORM

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a resin coated fiber-reinforced tubular form with a tubular core material oriented in the peripheral direction of reinforcing fiber and also with superior strength and rigidity in the peripheral direction due to the efficient orientation of the reinforcing fiber in the peripheral direction of the tubular core material. SOLUTION: A resin molten mixture containing reinforcing fiber 40 and thermoplastic resin 41 is injected into the first cylindrical flow path 31 of a cross head die 14. In addition, a rotary die 22 is arranged at least, on one of the inner or the outer side of the first cylindrical flow path 31, and the mixture is shaped so that it receives a torsional shear while passing through the first cylindrical flow path 31 to form a tubular core material 51. Next, the tubular core material 52 is guided into a second cylindrical flow path 32 with the inner and the outer peripheral face divided by a fixed wall part. In the second cylindrical flow path 32, other molten thermoplastic resins 42, 43 are coated at least, on one of the inner or the outer faces of the tubular core material 51. Finally, the coated tubular core material 51 is molded into a fiber-reinforced tubular form 54 with coated layers 52, 53 by coextrusion process.