Ejection Tabs for Compression Molding Tools and Processes
AssigneeArris Composites Inc.
InventorsDaniel MELVIN, Nataniel JACOBSON
Life of this patent
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Abstract
A compression-molding tool includes “cutouts” (i.e., recesses) that are machined into the male mold portion of the tool along a boundary edge thereof. During molding, liquefied resin and fibers fill the cutouts, forming “ejection tabs” along the upper surface of the part. The ejection tabs couple the part to the male mold/plunger. The ejection tabs, along with the finished part, remain coupled to the plunger as it is withdrawn from the female mold portion, thereby releasing the finished part from the mold cavity.
Claims22
A compression-molding tool, comprising:
- a female-mold portion comprising a mold cavity;
- and
- a male-mold portion comprising a plunger, the plunger having at least one ejection cutout disposed along a boundary edge of a part-forming surface of the plunger, wherein:
- (a) the ejection cutout has a first region that extends a first distance into the plunger, and a second region that extends a second distance into the plunger, wherein the first distance is less than the second distance,
- (b) when the molding tool is closed such that the male-mold portion couples to the female-mold portion, the first region provides a passageway between the mold cavity and the second region, thereby enabling liquefied resin to flow from the mold cavity through the first region and into the second region, the first region thus placing the ejection cutout in fluidic communication with the mold cavity.
A method for releasing a compression-molded part from a mold, the method comprising:
- providing a molding tool including:
- (i) a female-mold portion having a mold cavity, and
- (ii) a male-mold portion comprising a plunger, the plunger having at least one ejection cutout disposed along a boundary edge of a part-forming surface of the plunger;
- placing at least one of a plurality of preforms or a preform charge in the mold cavity and closing the molding tool, the plunger extending into the mold cavity;
- liquefying resin in the preforms or the preform charge, and flowing a first portion of the liquefied resin from the mold cavity into the ejection cutout and flowing a second portion of the liquefied resin throughout the mold cavity;
- cooling the molding tool, thereby solidifying the first portion of the resin and the second portion of the resin, wherein the first portion forms an ejection tab in the at least one ejection cutout, and the second portion forms a part, wherein the ejection tab is physically coupled to the part;
- and
- withdrawing the plunger from the mold cavity, thereby pulling the part out of the mold cavity without aid of ejector pins.
A method for releasing a part from a compression-molding tool, the method comprising:
- providing a compression-molding tool having at least one ejection cutout formed along a boundary edge of a part-forming surface of a male-mold portion of the tool;
- during compression molding, flowing, into the at least one ejection cutout, a first portion of a liquified resin present in a mold cavity of a female-mold portion of the tool, and flowing, throughout the mold cavity, a second portion of the liquified resin;
- cooling the compression-molding tool, thereby solidifying the first portion of the liquified resin, thereby forming at least one ejection tab, and solidifying the second portion of the liquified resin, thereby forming the part, wherein the ejection tab is coupled to the part and coupled to the male-mold portion;
- and
- withdrawing the male-mold portion from the mold cavity, thereby pulling the part out of the mold cavity without aid of ejector pins.
Dependencies are inferred from the claim text.