Honda Giken Kogyo Kabushiki Kaisha

Japan Polyolefins Co., Ltd.

Minoru Makuta

Hitoshi Ohgane

Atsushi Takeuchi

Kenji Hamabe

Osamu Aoki

Hirofumi Murakami

Kazuo Ito

Tatsuya Itakura

Takashi Nakayama

Kazuhiko Sakai

Akihiro Katagiri

Yoshio Kitawaki

Atushi Takeuchi

In producing a molded article of a synthetic resin, the following steps are used: a step of injecting an outer layer forming material into a molding cavity through a gate in a mold; a step of injecting a core forming material to allow the core forming material to flow into the outer layer forming material existing in the gate and the cavity and to allow the outer layer and core forming materials to flow within the cavity, thereby advancing the formation of the first construction portion; a step of allowing a front portion of the core forming material in a flowing direction to break through a front portion of the outer layer forming material in the flowing direction to flow into said cavity, thereby advancing the formation of the second construction portion under advancement of the first construction portion; and a step of pushing both the materials existing within the gate into said cavity by the outer layer material, thereby completing the formation of the first and second construction portion. Thus, it is possible to mass-produce a molded article of a synthetic resin including the first construction portion having a sandwich structure including a core and an outer layer, and the second construction portion having a single-layer structure.

Process for producing molded article made of synthetic resin

A resin composition utilizing coated resin moldings, the resin composition comprising 100 parts by weight of a crushed material of coated polyolefin resin moldings compounded with from 3 to 15 parts by weight of an ethylene polymer having a weight average molecular weight of from 50,000 to 180,000.

Resin composition utilizing coated resin moldings and multilayer resin

A process for producing a bumper of synthetic resin for use in an automobile, the bumper including a core and an outer layer covering the core. The process includes the steps of preparing a core forming material that includes a main component and a polyethylene added to the main component, the main component being produced by pulverizing a recovered bumper which has been formed using a polyolefin-based resin composition modified by an olefinic elastomer and which has a thermosetting synthetic resin coating film on its surface, and an outer layer forming material that includes the polyolefin-based resin composition modified by the olefinic elastomer and the polyethylene in a content A.sub.2 which is smaller than a content A.sub.1 of the polyethylene included in the core forming material (A.sub.2 &lt;A.sub.1); injecting the outer layer forming material through a feed channel into a bumper molding cavity in a mold; injecting the core forming material to flow into the outer layer forming material located in the feed channel and the cavity, and allowing the outer layer forming material and the core forming material to flow into the cavity; and pushing the outer layer forming material and the core forming material which are located in the feed channel into the cavity by the outer layer forming material thereby to form the core and the outer layer.

Process for producing automobile bumper made of synthetic resin

A process for producing a bumper for a vehicle uses a first step of injecting an outer layer forming material into a bumper forming cavity through a gate in a mold, and a second step of injecting a core forming material, thereby allowing the core forming material to flow into the outer layer forming material existing in said gate and said cavity, while allowing the outer layer and core forming materials to flow within the cavity. In the mold, the volume of a mounting portion forming area of the bumper forming cavity is set so that the thickness t.sub.1 of at least a mounting portion of the bumper for mounting to a vehicle body to extend laterally from a central portion of the vehicle body can be larger than the thickness t.sub.2 of a bumper main portion excluding the mounting portion, and the gate opens into the mounting portion forming area. Thus, the outer layer forming material can be allowed to flow substantially uniformly over the entire cavity, thereby enhancing the filling rate of the core forming material.

Process for producing a bumper for a vehicle

An outer layer forming material is injected into a cavity in a mold and then, a core forming material is injected, whereby the core forming material is allowed to flow into the outer layer forming material existing in the cavity, and both the materials are allowed to flow within the cavity. The cavity has a main area for forming a bumper main portion, and side areas for forming bumper sides. A relation, d.sub.1 &gt;d.sub.2 is established between a distance d.sub.1 determining a bumper thickness of a first section for forming an upper portion of the bumper main portion and a distance d.sub.2 determining a bumper thickness of a second section for forming a lower portion of the bumper main portion. A relation, d.sub.3 &gt;d.sub.1 is established between a distance d.sub.3 determining a bumper thickness of the side areas and the distance d.sub.1. A film gate opens into the first section. Thus, in the main area and the side areas, the times required for the filling of the outer layer forming material to be completed are substantially equal to each other.

Process for producing bumper made of synthetic resin for automobile

A multilayer resin molding, utilizing coated resin moldings, composed of a core material and a surface layer covering the core material, the core material being composed of a resin composition which comprises 100 parts by weight of a crushed material of coated polyolefin resin moldings compounded with from 3 to 15 parts by weight of an ethylene polymer having a weight average molecular weight of from 50,000 to 180,000 and the surface layer comprising a polypropylene resin composition comprising from 30 to 80% by weight of a propylene polymer, from 3 to 20% by weight of a propylene polymer modified with an unsaturated hydroxy compound, from 15 to 40% by weight of a thermoplastic elastomer, and from 0.1 to 10% by weight of an oligomer having a functional group at the terminal thereof.

Multilayer resin molding utilizing coated resin moldings

A bumper of synthetic resin for use in an automobile includes a core, and an outer layer covering the core. The material for forming the core includes a main component produced by pulverizing a recovered bumper which has been formed using a polyolefin-based resin composition modified by an olefinic elastomer and which has a thermosetting synthetic resin coating film on its surface, and a polyethylene added to the main component. The material for forming the outer layer includes the polyolefin-based resin composition modified by the olefinic elastomer and the polyethylene in a content A.sub.2 which is smaller than a content A.sub.1 of the polyethylene in the core forming material (A.sub.2 &lt;A.sub.1). The impact resistance of the core is enhanced with the addition of the polyethylene, despite the inclusion of the coating film particles. The outer layer is excellent in heat resisting characteristic, because of a smaller content of the polyethylene.

Growing community of inventors

Wako, Japan

Minoru Makuta