Patents by Inventor Steven Forrest North

Steven Forrest North has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4071479
    Abstract: Recompoundable polyvinyl chloride suitable to be recompounded for reuse, for example, in cable and wire production is recovered from a scrap material which includes plasticized polyvinyl chloride. A charge of plasticized polyvinyl chloride scrap material is treated with a solvent such as methyl ethyl ketone, tetrahydrofuran, cyclohexanone or dimethyl formamide to form a solvent mixture with one component thereof being a solvent solution of dissolved vinyl chloride polymer and plasticizers. The mixture is heated and agitated and scrap metal and other gross solids, if present, are removed. Then the solvent mixture is treated with an acid which advantageously causes a flocculation of suspended insolubles such as pigments and fillers. Except when using cyclohexanone as the solvent, the treatment with the acid must be accomplished, unexpectedly, in the presence of an additional flocculating agent such as a cellulose acetate which is soluble in the solution and which is insolubilized by the acid on refluxing.
    Type: Grant
    Filed: March 25, 1976
    Date of Patent: January 31, 1978
    Assignee: Western Electric Company, Inc.
    Inventors: Barret Broyde, Judith Archer Delles, Steven Forrest North