Plastic particle coated with processing aid and method of coating
AssigneeThe Dow Chemical Company
InventorPaul T. Louks
Life of this patent
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Abstract
Plastic particles showing improved behavior upon extrusion, comprising coating the particles with a fused layer of certain waxes or polymeric materials; and a method of preparation, comprising heating the plastic particles to a temperature just below the softening or fusing temperature of the additive while blending the particle in a high intensity blender, introducing the additive and maintaining intense blending until the temperature is above the fusing temperature of the additive, and discharging the coated particles from the blender.
Claims17
A process for preparing a particle having improved extrudability, which process comprises the steps of:
- (A) providing a plastic in particle form, and a processing aid having a softening point between ambient temperatures and below the processing temperature of the plastic in particle form:
- (B) charging the particle into a high intensity blender, said blender having an impeller:
- (C) rotating the blender impeller at a speed and for a period of time effective to raise the temperature of the particle surface to between about 5.degree. C. and 10.degree. C. below the softening point of the processing aid;
- (D) charging the processing aid into the blender such that the processing aid contacts the heated particle surface:
- and (E) rotating the blender impeller at a speed and for a period of time effective to raise the temperature of the particle surface to a temperature above the softening point of the processing aid, and to coat a portion of the particle surface by fusing the processing aid thereto.
Dependencies are inferred from the claim text.