| Glass fibers are widely used as an additive for thermoplastics to enhance stiffness, strength, high dimensional stability and high temperature performance. The use of glass fiber reinforcement has allowed thermoplastics to be used in a wider range of structural applications. One problem that can be associated with the use of glass fiber reinforced thermoplastics is the fiber length degradation that occurs during plastics processing and by granulation. This is a particular problem for glass fiber reinforced thermoplastics that are used in applications in which recycling is required, for example when the runner scrap is reused.;In this study, the effect on tensile, flexural, and izod impact properties, glass fiber degradation and granulator residence time with respect to granulator screen size and recycle history has been studied for long, medium and short glass fiber reinforced polypropylene. The results of the study showed that long, medium and short glass fiber reinforced materials show deterioration in mechanical properties as the number of recycle history increased. The effect of different granulator screen size on mechanical properties was less significant. The changes in mechanical properties have been attributed to fiber length degradation with respect to different granulator screen sizes and the increment in recycle histories. |
