Polypropylene (PP) belongs among the most important commodity plastics due to its widespread application. The color of the PP products can be achieved by the addition of pigments, which can dramatically affect its material characteristics. To maintain product consistency (dimensional, mechanical, and optical), knowledge of these implications is of great importance. This study investigates the effect of transparent/opaque green masterbatches (MBs) and their concentration on the physico-mechanical and optical properties of PP produced by injection molding. The results showed that selected pigments had different nucleating abilities, affecting the dimensional stability and crystallinity of the product. The rheological properties of pigmented PP melts were affected as well. Mechanical testing showed that the presence of both pigments increased the tensile strength and Young’s modulus, while the elongation at break was significantly increased only for the opaque MB. The impact toughness of colored PP with both MBs remained similar to that of neat PP. The optical properties were well controlled by the dosing of MBs, and were further related to the RAL color standards, as demonstrated by CIE color space analysis. Finally, the selection of appropriate pigments for PP should be considered, especially in areas where dimensional and color stability, as well as product safety, are highly important.

Additive technologies are becoming a common part of not only prototype production, but also piece or small series production. However, the choice of technology and material plays a key role in the applicability of the manufactured parts. The m...

This experimental study deals with the influence of pigments on the mechanical properties of polymeric polycarbonate material Lexan 923c, which is commonly used in industry and is being processed with injection technology. This material was stained with three different pigments from Lifokolor. It was also stained with 6 different concentrations of selected pigments. Emphasis was placed on measuring the tensile strength, impact strength and hardness of polyurethane mixtures.

The purpose of this work is to determine the influence of the reprocessed polymer on tensile properties. Tested samples were obtained using the injection molding technology from the industrial unpolluted waste, which is the same material as the virgin styrene acrylonitrile (SAN). The waste was mi...