Effects of manufacturing defects on thermoformed product quality

Abstract

In this study, 5% and 15% in weight carbon fiber reinforced polypropylene (PP) sheets were formed under appropriate vacuum and temperature conditions by using truncated cone-shaped thermoforming mold. In addition to this, 5% in weight glass fiber reinforced High Density Polyethylene (HDPE) sheets were formed using truncated cone-shaped, cylindrical, and cubic shaped thermoforming molds by thermoforming. Composite sheets used in this work were produced with a laboratory-type plastic extruder which has a screw diameter of 50 mm. In production of HDPE composite sheets, as a reinforcing material, chopped glass fibers (E-glass) which were provided from glass fiber manufacturer SISECAM A.S. Company were used. Using the same procedure PP (Borealis BE50-7032) thermoplastic granules were used as a matrix material in production of carbon fiber composite sheets. In carbon fiber reinforced sheets, chopped fibers were added during manufacturing. After thermoforming, composite semi-products were examined by visual inspection. Visual defects that affect product quality were obtained. Also carbon fiber distribution was investigated on different sections which were taken from the thermoformed semi-products by Scanning Electron Microscopy (SEM). Through this experimental study, it is aimed to investigate the effect of defects during plastic extrusion on thermoformed product quality.

Keywords

• Polypropylene (PP), High Density Polyethylene (HDPE), glass fiber, carbon fiber, thermoforming

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