Process of products UV-stabilized polyester materials
AssigneeGarware Plastics & Polyester Ltd.
InventorsShashikant B. Garware, Ramaswamy Ananthanarayanan
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Abstract
Polyesters are combined with UV-stabilizing substances in order to produce an end product, such as a film, sheet, ribbon or filament, by mixing polyester granules and the UV-stabilizing substance in powdered form at an elevated temperature such that at least the exterior surface of the polyester granules is soft, thereby to cause the powdered UV-stabilizing substance to adhere to the individual polymer granules, the granules with the powder adhering thereto are then dried, and they are then passed through an extruder or otherwise formed into an end product.
Claims18
The process of producing UV-stabilized polyester materials which comprises:
- (1) heating polyester granules to a temperature of about 150.degree.-180.degree. C.;
- (2) mixing a powdered UV-stabilizing substance with said heated granules, thereby producing polyester granules to which said powdered substance is attached;
- (3) then subjecting said powder-carrying granules to a drying step effective to reduce the moisture content thereof to no more than about 0.005% by weight;
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- (4) then forming said dried powder-carrying granules into a useful body, such as a film, sheet, ribbon or filament.
The process of producing UV-stabilized polyester materials which comprises:
- (1) heating polyester granules to a temperature at which the polymer surface of the granules becomes soft and sticky;
- (2) agitating said heated polyester granules and mixing them with a powdered UV-stabilizing substance, thereby to cause said powdered substance to adhere to said heated granules;
- (3) cooling said powder-carrying granules and separating fines therefrom;
- (4) drying said powder-carrying granules;
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- (5) then feeding said dried powder-carrying granules into an extruder and extruding the UV-stabilized polyester material therefrom.
Dependencies are inferred from the claim text.