Investigation and Analysis of the Influences of Glass Fiber Content and Orientation on the Dimension Change of Reinforced Polyamide Parts due to Moisture Absorption

The investigations in this work were focused on the determination and analysis of the factors such as contents and orientations of glass fibre, which influence the dimension change of reinforced polyamide parts significantly. The influence of various environmental conditions on dimensional changes of reinforced polyamide parts was also investigated and a correlation between the dimension change, glass fiber content and orientation under various conditions has been established.

On the basis of process parameters in the injection molding of the tested standard specimens and technical parts, the glass fibre orientations in the part were simulated with help of the software tool MoldFlow. In correlation with the determined expansion coefficients of standard specimens, the expansion of further standard specimens and of technical parts was calculated by the help of Finite Element Analysis. The calculated results for the polyamide parts were compared with the measured values.