Abstract: Introduction guides 12 are provided above and below a sheet-introduction opening portion of a pressure-reduced chamber 10, and heating means 17 is provided between the introduction guides. Each resin sheet 3 is attracted and attached respectively to the circumferential surface of a corresponding emboss roller 11 by reducing pressure. Pins 112 of the emboss roller 11 are truncated cone-shaped. The ratio of the total area of the lower bases of the pins 112 to the area of the circumferential surface of the emboss roller is 0.5 or more. The rising angle ? of the pin side face, in the vertical plane including the central axis of the pins 112, is in the range from 50 degrees to 70 degrees. Furthermore, a multilayered hollow structure plate 140 is formed by attaching non-air-permeable sheets 130 onto both the front and back of a core member obtained by fusing together hollow protrusions 112 in two thermoplastic resin sheets.

Abstract: Introduction guides 12 are provided above and below a sheet-introduction opening portion of a pressure-reduced chamber 10, and heating means 17 is provided between the introduction guides. Each resin sheet 3 is attracted and attached respectively to the circumferential surface of a corresponding emboss roller 11 by reducing pressure. Pins 112 of the emboss roller 11 are truncated cone-shaped. The ratio of the total area of the lower bases of the pins 112 to the area of the circumferential surface of the emboss roller is 0.5 or more. The rising angle ? of the pin side face, in the vertical plane including the central axis of the pins 112, is in the range from 50 degrees to 70 degrees. Furthermore, a multilayered hollow structure plate 140 is formed by attaching non-air-permeable sheets 130 onto both the front and back of a core member obtained by fusing together hollow protrusions 112 in two thermoplastic resin sheets.

Abstract: Introduction guides 12 are provided above and below a sheet-introduction opening portion of a pressure-reduced chamber 10, and heating means 17 is provided between the introduction guides. Each resin sheet 3 is attracted and attached respectively to the circumferential surface of a corresponding emboss roller 11 by reducing pressure. Pins 112 of the emboss roller 11 are truncated cone-shaped. The ratio of the total area of the lower bases of the pins 112 to the area of the circumferential surface of the emboss roller is 0.5 or more. The rising angle ? of the pin side face, in the vertical plane including the central axis of the pins 112, is in the range from 50 degrees to 70 degrees. Furthermore, a multilayered hollow structure plate 140 is formed by attaching non-air-permeable sheets 130 onto both the front and back of a core member obtained by fusing together hollow protrusions 112 in two thermoplastic resin sheets.

Abstract: Introduction guides 12 are provided above and below a sheet-introduction opening portion of a pressure-reduced chamber 10, and heating means 17 is provided between the introduction guides. Each resin sheet 3 is attracted and attached respectively to the circumferential surface of a corresponding emboss roller 11 by reducing pressure. Pins 112 of the emboss roller 11 are truncated cone-shaped. The ratio of the total area of the lower bases of the pins 112 to the area of the circumferential surface of the emboss roller is 0.5 or more. The rising angle ? of the pin side face, in the vertical plane including the central axis of the pins 112, is in the range from 50 degrees to 70 degrees. Furthermore, a multilayered hollow structure plate 140 is formed by attaching non-air-permeable sheets 130 onto both the front and back of a core member obtained by fusing together hollow protrusions 112 in two thermoplastic resin sheets.

Abstract: Introduction guides 12 are provided above and below a sheet-introduction opening portion of a pressure-reduced chamber 10, and heating means 17 is provided between the introduction guides. Each resin sheet 3 is attracted and attached respectively to the circumferential surface of a corresponding emboss roller 11 by reducing pressure. Pins 112 of the emboss roller 11 are truncated cone-shaped. The ratio of the total area of the lower bases of the pins 112 to the area of the circumferential surface of the emboss roller is 0.5 or more. The rising angle ? of the pin side face, in the vertical plane including the central axis of the pins 112, is in the range from 50 degrees to 70 degrees. Furthermore, a multilayered hollow structure plate 140 is formed by attaching non-air-permeable sheets 130 onto both the front and back of a core member obtained by fusing together hollow protrusions 112 in two thermoplastic resin sheets.

Abstract: In the manufacture of a fiber reinforced plastic armored cable, long reinforcing fibers are impregnated with an uncured thermosetting resin and formed into a predetermined shape to obtain a plurality of rod-like members with the thermosetting resin held uncured. Then the uncured rod-like members are passed through a die of a melt extruder, by which the rod-like members are each coated with a thermoplastic resin layer. The coated layers of the rod-like members are immediately cooled to simultaneously form a plurality of fiber reinforced plastic armoring strands with the thermosetting resin held uncured. The armoring strands thus obtained are wound around a cable which is fed while being rotated. The cable having wound thereon the strands is passed through a die portion of a melt extruder, by which the cable is sheathed with a thermoplastic resin layer which is immediately cooled and solidified.

Abstract: A twisted FRP structure having sufficient strength and flexibility is produced by providing a rod member disposed centrally and twist a plurality of side strands twisted around the rod member in the same direction at a predetermined pitch. At least the side strand includes a composite strand having an FRP element from by impregnating fibers with an uncured thermosetting resin and a thermoplastic coating on such FRP element, the thermosetting resin being cured after the side strands are twisted around the rod member. The twisting pitch is not less than 25 times the outside diameter of the FRP element in the side strand.

Abstract: Continuous rod-like molding having a FRP core and an outer skin of thermoplastic resin is shaped by introducing the molding into a passage of a heated die, the passage having a diameter slightly smaller at an exit thereof than an initial diameter of the molding, plasticizing the thermoplastic resin by passing the molding through the passage, thereby removing a part of the outer skin, and solidifying the thermoplastic resin, thereby obtaining a product having a diameter equal to the diameter of the exit of the passage.

Abstract: A single-core cord of reinforced optical fiber comprising an optical fiber element including an optical fiber and a primary coating formed of silicone rubber and covering the optical fiber, and a secondary coating covering the optical fiber element. The secondary coating has a three-layer structure which comprises a reinforcing inner layer formed of longitudinally arranged reinforcing fibers and cured non-styrene binder comprising an unsaturated polyester resin containing a non-styrene monomer as a cross-linking agent, a reinforcing outer layer formed of fiber-reinforced cured styrene resin and a surface layer formed of thermoplastic resin, the reinforcing outer layer and the surface layer being intimately bonded together with an anchoring effect therebetween.

Abstract: A reinforced optical fiber includes a reinforcing inner layer interposed between a buffer layer of silicon rubber and a FRP layer made of styrene resin and fibers. The reinforcing inner layer is formed by binding filaments attached longitudinally onto the buffer layer with a non-styrene resin. The additional reinforcing inner layer improves crushing resistance and also keeps low an increase of transmission loss. The reinforcing inner layer directly covering the buffer layer is formed by the steps of longitudinally attaching dry filaments to the buffer layer and then impregnating the filaments with a curable resin.

Abstract: A method of forming a fiber reinforced synthetic resin rod-like molding including a rod-like core portion having at least in the outer portion thereof a reinforcing fiber bundle integrally adhered together by a thermosetting resin and a thermoplastic resin layer coating the core portion is disclosed. The outer surface portion of the core portion and the inner surface portion of the thermoplastic resin layer are integrally adhered together due to an anchor effect generated by contacting between the thermosetting resin and the thermoplastic resin in a semifluid state under pressure.