Bridgestone Corporation

Teruo Iwai

Yutaka Hirata

Taisuke Yonezawa

Toshio Iwasawa

Hiroyuki Kuroki

Masato Ohta

Masaya Hiramatsu

A mold that: makes it possible to manufacture a molded foam body wherein a reinforcing member extends to a portion of the outer face of the molded body main body that corresponds to a parting line in the inner face of the cavity of the mold; and prevents molding problems stemming from the reinforcing member getting into the aforementioned parting line. Also: a method for manufacturing a molded foam body using the aforementioned mold; and a molded foam body manufactured thereby. The aforementioned mold () is provided with a seal member () that seals the space between mating faces () of mold parts () when the mold is fastened, and said seal member () is designed so as to be able to seal the space between the mating faces () even if the reinforcing member () gets in between the mating faces () on the cavity () side of the seal member ().

Mold, method for manufacturing molded foam body, and molded foam body

A mold that: makes it possible to manufacture a molded foam body wherein a reinforcing member extends to a portion of an outer face of the molded body main body that corresponds to a parting line in the inner face of the cavity of the mold; and prevents molding problems stemming from the reinforcing member getting into the aforementioned parting line. Also: a method for manufacturing a molded foam body using the aforementioned mold; and a molded foam body manufactured thereby. A recessed step portion () that faces the cavity () of the aforementioned mold () is provided in the mating face () of at least one part () of said mold (), at at least a portion of the parting line (P) (formed in the inner face of the cavity ()) adjacent to which the reinforcing member () is disposed. Said recessed step portion () is designed such that if the reinforcing member () gets in between the mating faces () at the parting line (P) when the mold is fastened, said reinforcing member () can escape into the recessed step portion ().

An embedment member of a foamed resin article such as a seat pad formed in a mold. The mold is provided with engaging projections and a pocket portion formed in or on an inner surface of a core thereof. A surface of the embedment member is positioned to face the core and the surface is superposed onto the surface of the core such that the projections enter into large opening portions. Then, the embedment member is slid in such a manner as to introduce the projections into narrow portions and wide portions, thereby retaining the embedment member to the core. In this state, an end portion of the embedment member is fitted into the pocket portion. To release the foamed resin article from the mold, the foamed resin article is slid in a direction opposite to the direction of the aforementioned sliding.

Formation of foamed resin article

A molding die for efficiently molding a material for a synthetic resin molded foam at a high expansion ratio, a low density, and a high yield with the least occurrence of burrs or flashes. In this molding die, the upper die is mounted on the lower die to form an enclosed cavity therebetween. An opening portion is formed in the upper die, and a cylindrical chamber member with its head closed is air-tightly mounted on the upper die to cover the opening portion. A piston is provided in a chamber in the chamber member such that when a leading end portion of the piston is inserted in the opening portion, a micro-spacing for communicating the cavity to the chamber is formed between the leading end portion of the piston and the opening portion. A piston drive means for vertically moving the piston and for usually setting a leading end surface of the piston at a lower surface of the upper die is provided in the chamber. A pressure adjusting means is provided for evacuating air in the chamber to reduce a pressure in the chamber. In the molding die, when the air in the chamber is evacuated, air in the cavity is also evacuated through the micro-spacing.

Molding die and molding process for synthetic resin molded foam

A mold for foam molding a material for a synthetic resin molded foam, includes a mold main body having: a lower mold half; an upper mold half removably disposed on the lower mold half in such a manner as to cover an opening portion of the lower mold half for forming an enclosed space therebetween; and a middle mold part removably disposed in the enclosed space. In the mold main body, a plurality of spacers, spaced from each other in the circumferential direction, are provided between the middle mold part and the upper mold half; chambers, partitioned from each other by the spacers, are formed between the upper surface of the middle mold part and the lower surface of the lower mold half; and a cavity communicated to the chambers through gaps between the spacers and through a micro-gap formed between the middle mold part and the lower mold half, is formed between the middle mold part and the lower mold half, wherein a synthetic resin foam molding material is supplied into the cavity. The mold also includes a pressure adjusting device for depressurizing the interior of the chambers by evacuating air in the chambers. In this mold, when the air in the chambers is evacuated, air in the cavity is simultaneously evacuated through the gaps between the spacers and the micro-gap between the middle mold part and the lower mold half.

Mold for making synthetic resin molded foam and molding process using

A mold apparatus for producing a synthetic resin foam part has a mold assembly (1) comprising a lower mold (2), an upper mold (3) removably attached to the lower mold to define a closed space, and an insert (4) removably disposed in the closed space. The insert has a partition (6) which is faced to the upper mold through a gap (11). The partition defines a chamber (7) between the insert and the upper mold. The closed space excluding the chamber constitutes a cavity (8) into which a molding compound is introduced. A pressure regulator means (21) is provided for exhausting air from the chamber (7) to keep the chamber in a subatmospheric pressure whereby air in the cavity (8) is also exhausted through the gap. A foam part is produced by feeding a synthetic resin blow molding compound into the cavity (8) under atmospheric pressure, tightly closing the mold assembly, exhausting air from the chamber and from the cavity through the gap to establish a subatmospheric pressure in the cavity, and causing the molding compound to be blow molded.

Method for molding expanded synthetic resin

A mold apparatus for producing a synthetic resin foam part has a mold assembly (1) including a lower mold (2), an upper mold (3) removably attached to the lower mold to define a closed space, and an insert (4) removably disposed in the closed space. The insert has a partition (6) which is faced to the upper mold through a gap (11). The partition defines a chamber (7) between the insert and the upper mold. The closed space excluding the chamber constitutes a cavity (8) into which a molding compound is introduced. A pressure regulator means (21) is provided for exhausting air from the chamber (7) to keep the chamber in a subatmospheric pressure whereby air in the cavity (8) is also exhausted through the gap. A foam part is produced by feeding a synthetic resin blow molding compound into the cavity (8) under atmospheric pressure, tightly closing the mold assembly, exhausting air from the chamber and from the cavity through the gap to establish a subatmospheric pressure in the cavity, and causing the molding compound to be blow molded.

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Yokohama, Japan

Teruo Iwai