Molding process employing heated fluid
AssigneeKonal Engineering and Equipment Inc.
InventorDouglas J. McNally
Life of this patent
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Abstract
A molding apparatus and method for forming a thermoplastic shell or skin product. The molding apparatus includes a hollow mold housing provided with a mold tool thereon, which together define a fluid chamber within the mold housing. A quantity of heated liquid is supplied at a predetermined or operating temperature to the chamber of the mold housing from a liquid supply via an elongate feed pipe until a rear surface of the mold tool is covered. The mold housing is then oscillated to uniformly distribute the heated liquid within the chamber and to effect uniform heating of the mold tool. Heating devices are located within the chamber of the mold housing to add heat to the liquid within the housing chamber to maintain a desired liquid temperature.
Claims23
A method of molding thermoplastic particles into a thin-walled article in a mold arrangement including a generally hollow mold housing having a thin mold tool provided on one side thereof and having a contoured front mold face which defines a mold cavity, the mold housing along with a back surface of the mold tool defining a fluid chamber within the interior of the mold housing, said method comprising the steps of:
- partially filling the mold housing chamber with a defined quantity of heated liquid until the back surface of the mold tool is covered with liquid to heat same;
- adding heat to the liquid within the mold housing chamber to maintain the liquid at a predetermined uniform temperature without adding further liquid to the mold housing chamber;
- and
- supplying plastic particles for contact with the heated front face of the mold tool to permit adhering and melting of the particles on the front mold face to form a thin-walled article.
A method of molding thermoplastic particles into a thin walled article in a mold arrangement including a generally hollow and rotatable mold housing having a thin mold tool provided on one side thereof and having a contoured front mold face which defines a mold cavity, the mold housing along with a back surface of the mold tool defining a liquid chamber within the interior of the mold housing, said method comprising the steps of:
- positioning the mold housing in a position wherein the front face of the mold tool faces generally downwardly;
- partially filling the mold housing chamber with a batch of heated liquid of a defined quantity until the back surface of the mold tool is covered with liquid to heat same;
- adding heat to the liquid within the mold housing chamber to maintain the liquid therein at a predetermined uniform temperature without adding further liquid to the mold housing chamber;
- supplying plastic particles for contact with the heated front face of the mold tool to permit adhering and melting of the particles thereon to form a thin walled article;
- and
- discharging the heated liquid from the mold housing chamber using gravitational forces.
A method of molding thermoplastic particles into a thin-walled article in a mold arrangement including a hollow mold housing having a mold tool provided on one side thereof and having a front face which defines a mold cavity, the mold housing along with a back surface of the mold tool defining a closed fluid chamber, said method comprising the steps of:
- adding a batch of liquid to the fluid chamber so as to cover the back surface of the mold tool and heat same;
- agitating the liquid within the fluid chamber to effect uniform heat transfer from the liquid to the mold tool;
- adding heat to the liquid within the fluid chamber without adding further liquid by providing an electric heating element disposed within the fluid chamber to maintain the liquid at a predetermined temperature;
- and
- contacting the heated front face of the mold tool with plastic particles to form a thin-walled article.
Dependencies are inferred from the claim text.