| 摘要 |
PROBLEM TO BE SOLVED: To obtain a low-cost FRP tank with an inner surface rib which can sufficiently endure against soil pressure by forming the FRP inner surface rib having glass roving in the annular groove formed on the outer periphery of a mandrel, and laminating the FRP from above a split mold. SOLUTION: An inner surface rib forming annular groove 2 is formed on the outer periphery of a mandrel 1 which can be exanded and contracted in diameter, and a split mold 3 is set. Then, the groove 2 is coated with chopped roving glass and thermosetting resin while rotating the mandrel 1, and wound with the roving impregnated with the resin in the circumferential direction from above to form an inner surface rib 7. Then, nonwoven fabric 9 and glass roving are wound on the mold 3 while rotating the mandrel 1, and the chopped glass roving is sprayed with thermosetting resin from above to form a tank right body 10 formed with the rib 7 integrally with the inner surface. |
