Investigation of the Moldability Parameters of PEG Based Steatite Feedstocks by Powder Injection Molding

摘要

In powder injection molding (PIM) barrel temperature, injection pressure and injection rate are important parameters for the molding of powder-binder mixtures. Improperly selected parameters lead to undesired problems such as separation of the powder-binder mixture and formation of collapses and cracks on the structure of the molded parts. In this study, steatite feedstocks based on PEG (polyethylene glycol) binders were injection molded into rectangular shape, ordered thickness with steps and zig-zag shaped mold cavities. The effects of the temperature and pressure of injection, rate of filling, temperature of the mold wall and geometry of the mold cavities were investigated. The optimum molding parameters of the feedstocks for the zig-zag shaped mold were determined to be an injection pressure of 80 to 140 MPa, a barrel temperature of 190 to 230°C, an injection rate of 5-25 · 10~(-6) m~3 s~(-1) and a mold wall temperature of 32 °C.