Flow property shelf life of PVC dry blend powders
AssigneeUnited Technologies Automotive, Inc.
InventorsJoseph T. Donatti, Robert P. Cavender, Robert J. Stein, James Carter
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Abstract
A method of cooling a PVC dry blend powder in a vessel by spraying a liquified inert gas into the vessel such that the liquified inert gas contacts the powder. The PVC dry blend powder is made by mixing a powdered PVC resin with ingredients selected from the group consisting of plasticizers, stabilizers, and pigments in a mixing vessel by using a heating and mixing cycle followed by a liquified inert gas cooling cycle. The flow properties of PVC dry blend powder made by this method have an improved shelf life.
Claims5
A method of making a PVC dry blend powder having improved flow property shelf life comprising, mixing a powdered PVC resin with ingredients selected from the group consisting of plasticizers, stabilizers, and pigments in a mixing vessel by using a heating and mixing cycle followed by a cooling cycle, wherein the improvement comprises:
- spraying a liquified inert gas into the vessel during the cooling cycle such that the liquified inert gas contacts the PVC dry blend powder, thereby cooling the PVC dry blend powder and producing a PVC dry blend powder having an improved flow property shelf life.
Dependencies are inferred from the claim text.