Process and apparatus for injection molding of molded parts having at least one cavity
AssigneeBattenfeld GmbH
InventorsHelmut Eckardt, Stephan van der Steen, Marc Wulfrath, Rolf Schwesinger
Life of this patent
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Abstract
A process for injection molding of molded parts made from thermoplastic plastic material having at least one cavity, which includes: a) injection of thermoplastic plastic melt from an injection unit along a melt flow path into the cavity of an injection-molding die; b) injection of a fluid into the still molten plastic material, so that the latter is pressed against the walls of the cavity; c) allowing the plastic material to cool until the latter forms the molded part in self-supporting manner; and d) releasing the molded part from the cavity of the injection-molding die.
Claims36
Process for injection molding of a molded part made from plastic material having at least one cavity, comprising:
- a) injection of plastic melt from an injection unit along a melt flow path into a cavity of an injection-molding die;
- b) injection of a fluid into the still molten plastic material, so that the latter is pressed against walls of the cavity to form the at least one cavity;
- c) allowing the plastic material to cool until the latter forms the molded part in self-supporting manner;
- and
- d) releasing the molded part from the cavity of the injection-molding die;
- wherein filling of the cavity of the injection-molding die with plastic melt according to step a) is effected so that the injection-molding die cavity is filled completely volumetrically with plastic melt, and liquid is used as fluid, which according to step b) is injected into the still molten plastic material;
- and wherein during or after step b) and before step c), compressed gas is introduced into the at least one cavity formed by the liquid in the molded part.
Process for injection molding of a molded part formed from a plastic material and having at least one cavity, comprising:
- a) injecting plastic melt into a cavity of an injection-molding die to substantially volumetrically fill the same with plastic melt;
- b) injecting a liquid into the cavity of the injection-molding die while the plastic melt is still at least partially melted so as to press at least some of the plastic melt against at least one wall of the injection-molding die to form the at least one cavity in the part;
- c) injecting compressed gas into the at least one cavity of the part;
- d) allowing the plastic melt to cool until it forms the molded part in a self-supporting manner;
- and
- e) releasing the molded part from the cavity of the injection-molding die.
Process for injection molding of a molded part formed from a plastic material and having at least one cavity, comprising:
- a) injecting plastic melt into a cavity of an injection-molding die to at least partially fill the same with plastic melt;
- b) injecting a liquid into the cavity of the injection-molding die while the plastic melt is still at least partially melted so as to press at least some of the plastic melt against at least one wall of the injection-molding die to form the at least one cavity in the part;
- c) injecting compressed gas into the at least one cavity of the part;
- d) allowing the plastic melt to cool until it forms the molded part in a self-supporting manner;
- and
- e) releasing the molded part from the cavity of the injection-molding die.
An apparatus for forming an injection-molded part having at least one cavity therein, comprising:
- an injection-molding die having at least one cavity where the injection-molded part is formed;
- an injection unit for injecting the at least one cavity of the injection-molding die with plastic melt;
- a supply of liquid that is injected into the at least one cavity of the injection-molding die while the plastic melt is still at least partially melted so as to press the plastic melt against at least one wall of the injection-molding die to form the at least one cavity in the part;
- and
- a supply of compressed gas that is injected into the at least one cavity of the part while the part is at least partially melted.
Dependencies are inferred from the claim text.