Method and apparatus for molding two-color polyurethane parts by RIM
AssigneeToyoda Gosei Co., Ltd.
InventorsNaohisa Nagasaka, Masayuki Goto, Shogo Sugiyama, Yukio Kawakita, Masanao Ishikake
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Abstract
Provided is a method of making a multi-property polyurethane part by RIM having a surface layer and an interior layer. The surface layer and the interior layer have different properties. The pressure in the cavity of the mold is reduced and a surface forming RIM polyurethane material is injected into the evacuated cavity, whereby the surface layer of the molded part is formed by RIM. An interior forming RIM polyurethane material is injected into the evacuated cavity, whereby the interior of the molded part is also formed by RIM.
Claims21
A method of molding a part comprising a surface layer and an interior layer, the method comprising the steps of:
- reducing the pressure in a cavity of a mold;
- mixing surface-forming material components in a first head to form a surface-forming material;
- injecting the surface-forming material into the evacuated cavity through a gate, thereby forming the surface layer;
- mixing interior-forming material components in a second head to form an interior-forming material;
- and
- injecting the interior-forming material into the evacuated cavity through the gate, thereby forming the interior layer,
- wherein the reduced pressure in the cavity degasses the surface-forming material and foams the interior-forming material.
An apparatus for molding a surface-forming material and an interior-forming material to obtain a molded part comprising a surface layer and an interior layer, the apparatus comprising:
- a mold having a mold cavity therein and being selectively openable;
- a gate in communication with said mold cavity;
- a first head constructed and arranged to mix surface-forming material components therein to thereby obtain the surface-forming material, said first head communicating with the gate;
- a second head constructed and arranged to mix interior-forming material components therein to thereby obtain the interior-forming material, said second head communicating with the gate;
- and
- means for reducing the pressure in said mold cavity to an extent sufficient to degas the surface-forming material and to foam the interior-forming material.
A method of molding a part comprising a surface layer and an interior layer, the method comprising the steps of:
- reducing the pressure in a cavity of a mold;
- mixing surface-forming material components in a first head to form a surface-forming material;
- injecting the surface-forming material into the evacuated cavity through a surface-forming gate, thereby forming the surface layer;
- mixing interior-forming material components in a second head to form an interior-forming material;
- and
- injecting the interior-forming material into the evacuated cavity through an interior-forming gate, thereby forming the interior layer, the interior-forming gate being at a different location than the surface-forming gate, wherein the reduced pressure in the cavity degasses the surface-forming material and foams the interior-forming material.
An apparatus for molding a surface-forming material and an interior-forming material to obtain a molded part comprising a surface layer and an interior layer having different properties, the apparatus comprising:
- a mold having a cavity therein and being selectively openable;
- a surface-forming gate and an interior-forming gate in communication with said mold cavity at different positions, respectively;
- a first head constructed and arranged to mix surface-forming material components therein to thereby obtain the surface-forming material, said first head communicating with said surface-forming gate;
- a second head constructed and arranged to mix interior-forming material components therein to thereby obtain the interior-forming material, said second head communicating with said interior-forming gate;
- and
- means for reducing the pressure in said mold cavity to an extent sufficient to degas the surface-forming material and to foam the interior-foaming material.
Dependencies are inferred from the claim text.