Abstract
A series of FRTP were prepared from a commercial polypropylene and an experimental fibrous anhydrite (anhydrous gypsum), of which dimensions were 1 to 2μm thick and 50 to 100μm long. Blending experiments were conducted in accordance with the plans for a series of L27 (33) factorial experiments, where three characteristics of resultant composites, the homogeneity of the filler dispersion, tensile modulus, and tensile strength, were statistically analyzed in terms of four processing factors, the kneeder employed, the disentanglement degree of raw filler fiber, the content of filler, and the premixing procedure of raw materials. After being blended in molten state, the resultant composites were emerged through a fine capillary to form monofilaments and then cut into fine chips. Some part of these fine chips was compression-molded into thin sheets for tensile experiments and the rest was subjected to determine the density distribution. The standard deviation of the density distribution was calculated to estimate the homogeneity of the filler dispersion in the composites. The analysis of variance for these three characteristics revealed that the homogeneity of the filler dispersion was significantly affected by the kneeder employed and the filler content. The tensile modulus was influenced by the kneeder, the composition, and the premixing procedure but the tensile strength was a simple function of the filler content. In addition, a minor interaction between the kneeder and the filler content was found for the standard deviation of the density distribution of the resultant composites.
