Abstract: A mandrel structure for use in manufacturing a fiber reinforced resin vessel by a filament winding process, includes: a shaft having a pair of axial ends configured to be supported by a drive unit; a mandrel having the shaft passed therethrough; and a pair of fittings having the shaft passed therethrough and projecting axially from respective axial ends of the mandrel. The mandrel is formed as a hollow shell made of a water-soluble material, and includes a pair of shaft holes receiving the shaft therein, and a receiving recess formed in a part of the mandrel surrounding each shaft hole and configured to engage the corresponding fitting in a rotationally fast manner.

Abstract: A mandrel for manufacturing a fiber reinforced resin vessel by a filament winding process includes: a tubular part; and a pair of end parts joined to respective axial ends of the tubular part. The tubular part and the end parts are each made of a molded product of a material including pulp and a starch-based binder.

Abstract: A mandrel structure for use in manufacturing a fiber reinforced resin vessel by a filament winding process, includes: a shaft having a pair of axial ends configured to be supported by a drive unit; a mandrel having the shaft passed therethrough; and a pair of fittings having the shaft passed therethrough and projecting axially from respective axial ends of the mandrel. The mandrel is formed as a hollow shell made of a water-soluble material, and includes a pair of shaft holes receiving the shaft therein, and a receiving recess formed in a part of the mandrel surrounding each shaft hole and configured to engage the corresponding fitting in a rotationally fast manner.

Abstract: A mandrel for manufacturing a fiber reinforced resin vessel by a filament winding process includes: a tubular part; and a pair of end parts joined to respective axial ends of the tubular part. The tubular part and the end parts are each made of a molded product of a material including pulp and a starch-based binder.

Abstract: In a pressure vessel formed by a fiber reinforced resin including reinforcing fibers and thermosetting resin impregnated in the reinforcing fibers, the fiber reinforced resin contains nylon particles dispersed in the thermosetting resin. Also disclosed is a method of manufacturing a pressure vessel including dispersing nylon particles in molten thermosetting resin, impregnating reinforcing fibers with the molten thermosetting resin having the nylon particles dispersed therein, wrapping the reinforcing fibers impregnated with the molten thermosetting resin around a mandrel, heating the reinforcing fibers and the thermosetting resin to cure the thermosetting resin, and removing the mandrel from the thermosetting resin after curing the thermosetting resin.

Abstract: To provide resin-coated sand for a multilayer mold in which the consolidation strength of the casting mold obtained by using it and gas permeability thereof are improved at the same time, the amount of occurrence of pyrolytic products (tar, soot and the like) derived from organic substances is effectively inhibited, when molding is performed using such a casting mold, and further, the casting mold after molding can exhibit excellent collapsibility. Disclosed is resin-coated sand for a multilayer mold, in which surfaces of refractory particles are coated with a binder composition containing a phenolic novolak resin having an ortho/para bond ratio of methylene groups of 1.5 or more and an aromatic amine as indispensable constituents, and the grain fineness number is from 80 to 150.

Abstract: To provide resin-coated sand for a multilayer mold in which the consolidation strength of the casting mold obtained by using it and gas permeability thereof are improved at the same time, the amount of occurrence of pyrolytic products (tar, soot and the like) derived from organic substances is effectively inhibited, when molding is performed using such a casting mold, and further, the casting mold after molding can exhibit excellent collapsibility. Disclosed is resin-coated sand for a multilayer mold, in which surfaces of refractory particles are coated with a binder composition containing a phenolic novolak resin having an ortho/para bond ratio of methylene groups of 1.5 or more and an aromatic amine as indispensable constituents, and the grain fineness number is from 80 to 150.