Polypropylene (PP) filler masterbatch is a type of additive used in injection molding to modify the properties of polypropylene-based plastics. It primarily consists of fine particles of minerals or other fillers that are incorporated into the PP resin during the molding process.

The presence of fillers in the PP matrix can enhance the dimensional stability of the molded parts, reducing the likelihood of warping, distortion, or changes in size over time. Some filler materials can improve the heat resistance of PP. This is valuable in applications where the molded parts may be exposed to elevated temperatures.

Fillers can contribute to a smoother surface finish on molded parts, reducing the need for extensive post-processing or finishing steps.