No abstract

In this research, polylactide was hybrid-reinforced and heat-treated in order to obtain durable structural materials with the use of eco-friendly components. Differential scanning calorimetry (DSC) analysis, tensile tests at various temperatures, Vicat tests, impact tests, and microscopic observations were conducted on the annealed and non-heat-treated specimens. The theoretical and true density, as well as water absorption, were also determined. The simultaneous introduction of chopped carbon and basalt fibers in equal mass fractions of 7.5% and 12.5% resulted in satisfactory increases in stiffness and tensile strength. The reinforcing effect was more efficient for the heat-treated composites, especially at elevated temperatures. Heat treatment significantly increased the degree of crystallinity of the matrix, improving heat resistance and reducing water absorption. It also reduced the stress concentrations in the injection-molded specimens.

Paper presents an analysis of 3D images of the composite with a polyamide (PA) matrix reinforced by short glass fibres. The aim of the study was the assessment of the orientation of the fibres. The algorithm used for analysis is based on describing ellipsoids on the detected objects for its orientation assessment. Three subsamples of 3D images were cropped from three different part of the original sample. Each subsample shows the visible difference in the fibre orientation. The detection of the fibres and the analysis of the direction were performed using open source software ImageJ. Analysis of obtained results shown that the ellipsoid method is sensitive to the differences in the fibre orientation and may deliver valuable information for structure description.