Abstract: The glass-fiber-yarn joined body 1 is provided with glass fiber yarns 2, 3, and a connection 5 in which a resin yarn 4 is wound around ends of both of the glass fiber yarns 2, 3, the ends being superimposed with each other. The connection 5 has a width W1 of 20 to 40 mm. When a connection diameter R as a total of diameters of the respective glass fiber yarns 2, 3 and the thickness of the resin yarn 4 wound around the connection 5 is 500 to 5000 ?m and a mass of each of the glass fiber yarns 2, 3 is 200 to 6000 tex, a value of a ratio of mass of each of the glass fiber yarns 2, 3 relative to the connection diameter R is in the range of 0.32 to 2.00.

Abstract: The glass-fiber-yarn joined body 1 is provided with glass fiber yarns 2, 3, and a connection 5 in which a resin yarn 4 is wound around ends of both of the glass fiber yarns 2, 3, the ends being superimposed with each other. The connection 5 has a width W1 of 20 to 40 mm. When a connection diameter R as a total of diameters of the respective glass fiber yarns 2, 3 and the thickness of the resin yarn 4 wound around the connection 5 is 500 to 5000 ?m and a mass of each of the glass fiber yarns 2, 3 is 200 to 6000 tex, a value of a ratio of mass of each of the glass fiber yarns 2, 3 relative to the connection diameter R is in the range of 0.32 to 2.00.

Abstract: Provided is a long-fiber-reinforced thermoplastic resin preform including glass fibers excellent in strength and modulus of elasticity and easily produced and a long-fiber-reinforced resin compact excellent in strength and modulus of elasticity. The long-fiber-reinforced thermoplastic resin preform is produced by cutting to a predetermined length glass fiber bundles impregnated with a thermoplastic resin and holding the thermoplastic resin around the glass fiber bundles, and includes the glass fiber bundles as long fiber bundles. The glass fiber bundles are formed by bundling glass fibers. The glass fibers have a composition wherein the content of SiO2 is 57.0 to 63.0% by mass, the content of Al2O3 is 19.0 to 23.0% by mass, the content of MgO is 10.0 to 15.0% by mass and the content of CaO is 5.5 to 11.0% by mass, and the ratio MgO/CaO is 0.8 to 2.0.

Abstract: Provided is a long-fiber-reinforced thermoplastic resin preform including glass fibers excellent in strength and modulus of elasticity and easily produced and a long-fiber-reinforced resin compact excellent in strength and modulus of elasticity. The long-fiber-reinforced thermoplastic resin preform is produced by cutting to a predetermined length glass fiber bundles impregnated with a thermoplastic resin and holding the thermoplastic resin around the glass fiber bundles, and includes the glass fiber bundles as long fiber bundles. The glass fiber bundles are formed by bundling glass fibers. The glass fibers have a composition wherein the content of SiO2 is 57.0 to 63.0% by mass, the content of Al2O3 is 19.0 to 23.0% by mass, the content of MgO is 10.0 to 15.0% by mass and the content of CaO is 5.5 to 11.0% by mass, and the ratio MgO/CaO is 0.8 to 2.0.