Method for making extrudable polyvinyl alcohol compositions
Patent 5051222 Issued on September 24, 1991. Estimated Expiration Date: 
September 1, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
September 1, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3365413 3409598 3425979 3555616 3607812 3742093 3843757 Melt extrudable polyvinyl alcohol compositions Solvent removal from polymer solutions Polyvinyl alcohol compositions for use in the preparation of water-soluble films InventorsAssigneeApplicationNo. 402167 filed on 09/01/1989US Classes:264/143, From strands264/40.6, Controlling heat transfer with molding material264/101, VACUUM TREATMENT OF WORK264/185, Polyvinyl alcohol containing264/211.22, Filament (e.g., fiber, etc.)264/211.23, Plural screws, plural extruders, or plural stage extruder425/144, Of mold cavity or fluent material to shaping or discharging orifice425/203, With separate and distinct gas withdrawal chamber425/204, Plural means being diverse, or parallel and intermeshing or concentric425/376.1, STOCK PRESSURIZING MEANS OPERABLY ASSOCIATED WITH DOWNSTREAM SHAPING ORIFICE425/378.1Including heating or cooling meansExaminersPrimary: Thurlow, JefferyAttorney, Agent or FirmForeign Patent References
International ClassB29C 047/80AbstractA method for extruding polyvinyl alcohol which includesadding sufficient energy to the polyvinyl alcohol to both melt it and essentially eliminate the crystallinity in the melt, andsimultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol andrapidly cooling the extruded melt reduces the heat history and improves the resulting color of the extrudable polyvinyl alcohol.Field of SearchSubsequent to extruding stepFrom strands Cooling Screw extruder or screw feeder device Filament (e.g., fiber, etc.) Plural screws, plural extruders, or plural stage extruder Curing or polymerization in the extruder (includes incomplete polymerization or curing, or coagulating rubber) WITH MEASURING, TESTING, OR INSPECTING Controlling heat transfer with molding material Polyvinyl alcohol containing MISCELLANEOUS VACUUM TREATMENT OF WORK With separate and distinct gas withdrawal chamber Plural means being diverse, or parallel and intermeshing or concentric STOCK PRESSURIZING MEANS OPERABLY ASSOCIATED WITH DOWNSTREAM SHAPING ORIFICE Of mold cavity or fluent material to shaping or discharging orifice Including heating or cooling means | |
