Method and apparatus for injection molding parts which have at least one cavity
AssigneeBattenfeld GmbH
InventorHelmut Eckardt
Life of this patent
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Abstract
The invention relates to a method and an apparatus for injection molding thermoplastic molded parts, having at least one cavity. The method comprises the following steps: a) injecting thermoplastic melt from an injection unit along a melt flow path into the cavity of an injection molding tool; b) injecting a fluid into the still liquid plastic material, so that the plastic material is pressed against the walls of the cavity; c) allowing the plastic material to cool until it forms the self-supporting molded part; and d) removing the molded part from the cavity of the injection molding tool.
Claims36
A method for injection molding thermoplastic molded parts, having at least one cavity, comprising:
- a) injecting thermoplastic melt from an injection unit along a melt flow path into a cavity of an injection molding tool;
- b) injecting a fluid into the still liquid plastic material, so that the plastic material is pressed against walls of the cavity;
- c) allowing the plastic material to cool until it forms a self-supporting molded part;
- and
- d) removing the molded part from the cavity of the injection molding tool;
- the cavity being filled with plastic melt, according to step a), in such a way that the cavity is not filled completely with plastic melt;
- and the fluid, which is injected into the still liquid plastic material in accordance with step b) is a liquid with a high heat capacity, the surface of the cavity not being covered completely until the fluid is injected into the melted plastic material, and wherein, while the process step b) is executed, a portion of the still melted plastic material is displaced from the cavity into a demoldable secondary cavity.
A method for injection molding a part having at least one cavity therein, comprising:
- injecting thermoplastic melt from an injection unit along a melt flow path into a cavity of an injection molding tool to partially fill the cavity;
- injecting a fluid, which has a high heat capacity, into the thermoplastic melt to press the melt against walls of the cavity of the molding tool, the walls of the molding tool not being covered until the fluid is injected into the melted thermoplastic material, at least a portion of the thermoplastic material being displaced from the cavity into an overflow cavity;
- allowing the thermoplastic material to cool until it forms a self-supporting molded part;
- and
- removing the part from the cavity of the injection molding tool.
An apparatus for injection molding thermoplastic molded parts containing at least one cavity, comprising:
- an injection unit;
- an injection molding tool having a cavity, which has a melt flow path, over which the melted plastic material can be introduced into the cavity;
- an overflow cavity in fluid connection with the cavity;
- means for injecting a liquid into the cavity, the liquid having a high heat capacity;
- and
- means for removing the liquid situated in the cavity of the molded part.
Dependencies are inferred from the claim text.