ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The processability of polyethylene in sheet-extrusion or calendering may be improved by the addition of plastic flakes. The effects of plastic flake parameters and flow conditions on the viscosity and the die swell of the suspension were determined, and the structure in flow (morphology or dispersion state) and applications were discussed. Flakes of biaxially oriented polystyrene, high-impact polystyrene, polypropylene, polyamide or polypropylene spheres were dry-blended with polyethylene. The viscosity was determined by means of a slit or a capillary rheometer. The quenched extrudate was annealed and its die swell was measured. Flakes of biaxially oriented polystyrene shrunk into rod-like form during heating, but other plastics retained the flake-form. The relative viscosity and the swell ratio of the suspensions depended on the type of plastic and operating conditions. The rheological behavior of suspensions qualitatively suggested that polypropylene flakes deformed or crowded (including stacking), polyamide flakes deformed slightly, and polystyrene flakes were difficult to buckle, but crowded slightly. The thickness of extrudates can be controlled easily by flake addition due to decreased die swell, while the output would be reduced to some extent.
Additional Material:
11 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760220310
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