Process for gas assisted and water assisted injection molding
AssigneeAlliance Gas Systems, Inc.
InventorRonald Thomas
Life of this patent
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Abstract
A liquid and gas assisted injection molding apparatus comprising a source of liquid coolant, a source of compressed gas, a source of heated viscous plastic, a mold cavity means for controllably injecting said plastic into said cavity, means for controllably injecting said compressed gas into said cavity, means for controllably injecting said liquid coolant into said cavity, and means for selectively controlling the injection of said plastic, gas and liquid coolant.
Claims11
A method of molding a plastic article comprising the steps of:
- injecting a heated viscous plastic into a closed mold cavity;
- injecting a gaseous fluid during the injection of said plastic to create a fluid space within the article and to urge the plastic to fill out the mold;
- injecting into said fluid space a non-compressible fluid to increase the pressure within the fluid space and to increase the cooling rate of said plastic;
- venting said non-compressible fluid from said cavity;
- and
- injecting additional gaseous fluid into said fluid space after at least some of said non-compressible fluid is vented.
A method of injection molding plastic parts comprising:
- injecting viscous plastic into a closed mold cavity;
- injecting a non-gaseous fluid into said mold cavity;
- injecting a gaseous fluid into said mold cavity prior to injecting said non-gaseous fluid;
- and
- injecting additional gaseous fluid after at least some of the non-gaseous fluid is vented.
A method of injection molding plastic parts comprising:
- injecting viscous plastic into a closed mold cavity;
- injecting a non-compressible fluid into id mold cavity;
- and
- injecting a compressible fluid into said mold cavity.
A method of injection molding plastic parts comprising:
- injecting viscous plastic into a closed mold cavity;
- injecting a compressible fluid into said mold cavity;
- and
- injecting water into said mold cavity.
Dependencies are inferred from the claim text.