Shrinkage study of textile roller molded by conventional/microcellular injection-molding process

One of the advantages of microcellular conventional injection molding over conventional injection molding is that the shrinkage of the part can be reduced. This project investigated the effect of the process parameters on the shrinkage of the textile roller by conventional/microcellular injection-molding process. Polybutyleneterephthalate (PBT) materials with 30 wt.% glass and Wollastonite fiber were used. The results showed that the shrinkage by microcellular injection molding is less than that of conventional injection molding. Glass fiber filled PBT has more shrinkage than Wollastonite fiber filled PBT due to the non-uniform cell size of the glass fiber filled PBT.