Filler material and wax composition for use in investment casting

摘要

A wax composition for use in investment casting having improved properties includes polyethylene terephthalate as a filler material. The amount of polyethylene terephthalate used in the wax composition ranges from about 5 to about 50 parts by weight of the total wax composition. The use of polyethylene terephthalate as the filler material is effective for controlling the expansion and contraction properties of the wax composition providing a high degree of dimensional accuracy. Polyethylene terephthalate is relatively inexpensive compared to other inert filler materials, does not react with the mold, allows the wax pattern to be readily removed from the mold with reduced tendencies for shell cracking and results in little or no appreciable ash residue upon firing.