| 摘要 |
PURPOSE:To obtain a laminated tube which is in perfect-round structure and stable in rigidity and bending strength, by a method wherein a prepreg constituted of an intermediate layer where a reinforcing fiber is arranged in a longitudinal direction and an upper and lower layers where the same material as that of intermediate layer is arranged in a lateral direction is cut off into amount equivalent to one turn winding round a core metal and the inside and outside of a joint of the prepreg is reinforced. CONSTITUTION:An intermediate layer is formed by arranging a reinforcing fiber composed of a high-strength and high-elastic fiber in a longitudinal direction under its basis weight falling within a range of 55-1,500g/m<2>. Then an upper and lower layers are formed by arranging a fiber of the same material as that of the intermediate layer or possessing about the same physical properties with that of the intermediate layer in a lateral direction under its basis weight falling within a range of 5-400g/m<2>, through which a three layer sheet is laminated. Then after the three layer sheet has been made into a prepreg by performing semidryness of the three layer sheet by impregnating the same with thermosetting resin, the prepreg is cut off into amount equivalent to one turn winding round a core metal. Lateral direction reinforcing sheets which are of the same material of about the same physical properties, basis weight and size as those of an upper and lower layers of the prepreg respectively are arranged as the upper and lower layers by shifting the lateral direction reinforcing sheet by amount of 1/10-1/3 of the circumference at the time of winding round the core metal in the direction of an end and the start of the winding of the same round the core metal. Then the prepreg and each of the sheets are wound round the core metal. |
