Fillers for polypropylene

Abstract

Behind PVC, particulate fillers are used in the second largest quantity in polypropylene (PP). Table 1 gives an estimate of the amount of fillers used in Western Europe and about the increase of their consumption. Three fillers are applied in considerable quantities: talc, CaCO3, glass fibers (GF). Mostly technical and technological reasons justify the application of fillers, since a separate compounding step increases the price of the composites considerably. Combination of fillers with PP results in a new material with changed properties; some of these changes are advantageous (improved stiffness, higher heat deflection temperature (HDT), better heat conductivity), while others are less favorable (decreased deformability and impact, wear of the equipment). An optimum of properties must be found during the development of a new material and selection of the proper type and grade of filler is always an important part of the process.