Composite molded article and manufacturing method thereof

A method for manufacturing a composite molded article which integrally includes:

• a main body member configured to be attached to a member to be attached, formed in an elongated shape from a polymer material having rigidity, and having a hollow space formed therein along a longitudinal direction thereof, and a cushion member formed from an elastic polymer material having a lower degree of hardness than the main body member, joined to an edge of the main body member, and having an elongated portion extending in the longitudinal direction along the edge, the method comprising:
• a step of preparing the main body member having at least one protruding portion on one surface of a peripheral wall surrounding the hollow space, the protruding portion protruding toward a direction away from the peripheral wall, having a root portion joined to the peripheral wall, and being configured to be broken at the root portion;
• a step of forming a through hole, which allows the hollow space to communicate with external air, in the peripheral wall, by breaking the protruding portion at the root portion after the molding of the main body member;
• a step of setting the main body member in an injection molding die when the injection molding die is open, by using the openable and closable injection molding die for molding the cushion member;
• a step of fixing the main body member within the injection molding die, forming a molding cavity for molding the cushion member by the main body member and a molding die face formed inside the injection molding die to at least a portion of the main body member in the longitudinal direction, and allowing the through hole to communicate with the molding cavity, by closing the injection molding die;
• and
• a step of injecting the heated and melted elastic polymer material from an injection gate after the injection molding die is closed, molding the cushion member by making a portion of the elastic polymer material flow into and fill the molding cavity, and forming a filling portion that fills the hollow space by making a portion of the elastic polymer material flow into and fill the hollow space from the through hole.

A method for manufacturing a composite molded article which integrally includes:

• a main body member configured to be attached to a member to be attached, formed in an elongated shape from a polymer material having rigidity, and having a hollow space formed therein along a longitudinal direction thereof;
• and a cushion member formed from an elastic polymer material having a lower degree of hardness than the main body member, joined to an edge of the main body member, and having an elongated portion extending in the longitudinal direction along the edge, the method comprising:
• a step of forming a first molding cavity by a molding die face formed inside a first injection molding die, by using the openable and closable first injection molding die for molding the main body member and closing the first injection molding die;
• a step of molding the main body member by filling the heated and melted polymer material into the first molding cavity from an injection gate after the injection molding die is closed and injecting a fluid into the inside of the polymer material to form the hollow space, and of molding at least one protruding portion on one surface of a peripheral wall of the main body member surrounding the hollow space, the protruding potion protruding toward a direction away from the peripheral wall, having a root portion joined to the peripheral wall, and being configured to be broken at the root portion;
• a step of forming a through hole, which allows the hollow space to communicate with external air, to the peripheral wall, by breaking the protruding portion at the root portion after the molding of the main body member;
• a step of setting the main body member in the second injection molding die when the second injection molding die is open, by using the openable and closable second injection molding die for molding the cushion member;
• a step of fixing the main body member within the second injection molding die, forming a second molding cavity for molding the cushion member by the main body member and a molding die face formed inside the second injection molding die to at least a portion of the main body member in the longitudinal direction, and allowing the through hole to communicate with the second molding cavity, by closing the second injection molding die;
• and
• a step of injecting the heated and melted elastic polymer material from an injection gate after the second injection molding die is closed, molding the cushion member by making a portion of the elastic polymer material flow into and fill the second molding cavity, and forming a filling portion that fills the hollow space by making a portion of the elastic polymer material flow into and fill the hollow space from the through hole.