Process for injection molding crystal polystyrene to form compact disc trays
OwnerMichael P. Schafer JR.inventor
Life of this patent
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Abstract
A process for mixing plastic resins to produce a material having properties similar to medium and high impact polystyrene after thermoforming. The process includes mixing crystal polystyrene and a styrenic thermoplastic elastomer to form a mixture for thermoforming. The process enables the substitution of crystal polystyrene for medium and high impact polystyrene in the production of items such as compact disc trays and the like.
Claims27
A method of providing a mixture of plastic resin for thermoforming, comprising the steps of:
- a) providing a predetermined quantity of crystal polystyrene;
- b) providing a predetermined quantity of thermoplastic elastomer;
- c) combining the crystal polystyrene and thermoplastic elastomer to form a mixture for thermoforming;
- and
- d) thermoforming the mixture to form an article.
A method of providing a mixture of plastic resin for injection molding comprising the steps of:
- a) providing a predetermined quantity of crystal polystyrene;
- b) providing a predetermined quantity of thermoplastic elastomer;
- c) providing a predetermined quantity of color additive;
- d) combining the crystal polystyrene, thermoplastic elastomer, and color additive to form a mixture for thermoforming;
- and
- d) thermoforming the mixture to form an article.
A method of providing a mixture of plastic resin for injection molding comprising the steps of:
- a) providing a predetermined quantity of crystal polystyrene;
- b) providing a predetermined quantity of thermoplastic elastomer;
- c) providing a predetermined quantity of color additive;
- d) providing a predetermined quantity of regrind selected from the group consisting of crystal polystyrene, medium impact polystyrene and high impact polystyrene;
- e) combining the crystal polystyrene, thermoplastic elastomer, color additive, and regrind to form a mixture for thermoforming;
- and
- f) thermoforming the mixture to form an article.
An article formed of molded thermoplastic material comprising crystal polystyrene in an amount of from about 75% to about 95% by weight and styrenic thermoplastic elastomer in an amount from about 5% to about 25% by weight.
Dependencies are inferred from the claim text.