Accession Number : ADA303085

Title :   Thickness Effects on Material Properties in a Glass/Thermoplastic P.E.T. Injection Molding Compound,

Corporate Author : DELAWARE UNIV NEWARK CENTER FOR COMPOSITE MATERIALS

Personal Author(s) : Wetherhold, Robert C. ; Dick, William A. ; Pipes, R. B.

PDF Url : ADA303085

Report Date : MAR 1980

Pagination or Media Count : 19

Abstract : Rynite 545, a commercial short glass fiber/ thermoplastic polyethylene terepthalate system, was injection molded into end-gated rectangular plaques of various thicknesses. The plaques were sectioned and characterized by scanning electron microscopy and by mechanical and thermal expansion tests. The glass fibers are shown to be highly aligned in 'boundary layers' near the mold surfaces, and are distributed more randomly away from the mold surfaces. As part thickness increased, the aligned fiber boundary layers occupied a smaller proportion of the cross section, resulting in a decrease in mechanical properties. Tensile moduli are derived for boundary and center layers, which can be used to accurately predict the effective moduli at different thicknesses. In addition, the boundary layer thicknesses at the top and bottom surfaces were unequal, producing noticeable warping for thicker plaques. (MM)

Descriptors :   *FIBER REINFORCED COMPOSITES, *GLASS FIBERS, *THERMOPLASTIC RESINS, *INJECTION MOLDING, THICKNESS, SCANNING ELECTRON MICROSCOPES, MICROSTRUCTURE, MANUFACTURING, POLYMERS, TENSILE PROPERTIES, ELASTIC PROPERTIES, BOUNDARY LAYER, GLASS, THERMAL EXPANSION, WEIGHT REDUCTION, POLYESTER PLASTICS, AUTOMOTIVE VEHICLES, AUTOMOTIVE INDUSTRY, MOLDING MATERIALS, REINFORCED PLASTICS, POLYETHYLENE TEREPHTHALATE.

Subject Categories : Laminates and Composite Materials
      Plastics
      Surface Transportation and Equipment
      Mfg & Industrial Eng & Control of Product Sys

Distribution Statement : APPROVED FOR PUBLIC RELEASE