Molding apparatus and manufacturing method for molded surface fastener

A manufacturing method of a synthetic resin molded surface fastener in which a plurality of engaging elements stand on an upper surface of a base portion wherein:

• the method includes molding the synthetic resin molded surface fastener using a molding apparatus having a die wheel driving rotationally in one direction and an extrusion nozzle discharging a molten synthetic resin material toward the die wheel, wherein the die wheel has a concentric double cylinder structure provided with an outer side cylindrical body and an inner side cylindrical body disposed in close contact with an inner peripheral surface of the outer side cylindrical body,
• wherein
• the method including using the die wheel in which a plurality of penetrating holes penetrating the outer side cylindrical body from an outer peripheral surface to the inner peripheral surface are provided, a plurality of grooved portions are grooved on an outer peripheral surface of the inner side cylindrical body, more grooved portions of the inner side cylindrical body are provided than the penetrating holes of the outer side cylindrical body in a certain region in a reference direction when at least one direction is defined as the reference direction, an outer peripheral edge of each penetrating hole on the inner peripheral surface of the outer side cylindrical body has a part overlapping the grooved portion of the inner side cylindrical body and a part in close contact with the outer peripheral surface of the inner side cylindrical body, and the grooved portions disposed on the inner side cylindrical body include a use grooved portion disposed to intersect with the penetrating hole on the outer side cylindrical body and into which the molten synthetic resin material can be flowed, and a non-use grooved portion disposed between the penetrating holes adjacent to each other on the outer side cylindrical body and covered by the inner peripheral surface of the outer side cylindrical body.

A manufacturing method of a molded surface fastener by conducting a primary molding step molding a primary molded body in which a plurality of provisional elements stand on an upper surface of a base portion using a molding apparatus having a die wheel driving rotationally in one direction and an extrusion nozzle discharging a molten synthetic resin material toward the die wheel, wherein the die wheel has a concentric double cylinder structure provided with an outer side cylindrical body and an inner side cylindrical body disposed in close contact with an inner peripheral surface of the outer side cylindrical body, and a secondary molding step heating and compressing a part of each provisional element of the primary molded body from above, wherein:

• the method including using the die wheel in which a plurality of penetrating holes penetrating the outer side cylindrical body from an outer peripheral surface to the inner peripheral surface are provided, a plurality of grooved portions are grooved on an outer peripheral surface of the inner side cylindrical body, more grooved portions of the inner side cylindrical body are provided than the penetrating holes of the outer side cylindrical body in a certain region in a reference direction when at least one direction is defined as the reference direction, an outer peripheral edge of each penetrating hole on the inner peripheral surface of the outer side cylindrical body has a part overlapping the grooved portion of the inner side cylindrical body and a part in close contact with the outer peripheral surface of the inner side cylindrical body, and the grooved portions disposed on the inner side cylindrical body include a use grooved portion disposed to intersect with the penetrating hole in the outer side cylindrical body and into which the molten synthetic resin material can be flowed, and a non-use grooved portion disposed between the penetrating holes adjacent to each other on the outer side cylindrical body and covered by the inner peripheral surface of the outer side cylindrical body.