Process and apparatus for injection molding of molded parts having at least one cavity
AssigneeBattenfeld GmbH
InventorMarc Wulfrath
Life of this patent
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Abstract
Process and apparatus for injection molding of molded parts made from plastic material having at least one cavity, which includes: a) injection of 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 solidify 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.
Claims34
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 the cavity of an injection-molding die;
- b) injection of a liquid into the still molten plastic material, so that the latter is pressed against the walls of the cavity;
- c) allowing the plastic material to solidify 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 after injecting the plastic melt according to step a) and after injecting the liquid according to step b), both the melt flow path and a flow path via which the liquid is injected, are closed, and wherein releasing according to step d) only takes place when the injected liquid has transferred at least partly to a gaseous state of aggregation, and wherein, before releasing according to step d), relieving of pressure in the interior of the molded part takes place by introducing a vent opening.
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;
- b) injecting a liquid into the cavity of the injection-molding die while the plastic melt is 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 of the part, the liquid at least partly transferring to a gaseous state;
- c) allowing the plastic material to cool until it forms the molded part in a self-supporting manner;
- d) relieving any pressure in the cavity of the injection-molding die by introducing a vent opening;
- and
- e) releasing the molded part from the cavity of the injection-molding die.
An apparatus for forming an injection-molded part formed from a plastic material and having at least one cavity, comprising:
- an injection-molding die having at least one cavity wherein 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 at least partially melted so as to press at least some of the melt against at least one wall of the injection-molding die to form the at least one cavity of the injection-molded part, the liquid at least partly transferring to a gaseous state;
- a mechanism for sealing the plastic melt and the liquid in the cavity of the injection-molding die;
- and
- a vent opening for relieving pressure in the cavity of the injection-molding die.
Dependencies are inferred from the claim text.