Precision Polishing Techniques for Metal Molding Dies and Glass Forming Technology “Slumping Method”

Precision manufacturing techniques are required for the fabrication of small and large optical components in various fields. To prepare molding dies with highly precise geometric shapes and surface roughness that are used in certain molding processes, polishing techniques have been investigated for many materials. In this research, the polishing techniques used for a SUS310S stainless steel molding die for the glass forming technology “slumping method” were investigated. The surface roughness of the polished SUS310S molding die surface was below Rz = 120 nm (P–V), Ra = 20 nm after 35 h of polishing with 0.5% alumina polishing liquid under a pressure of 1.7 kPa. In addition, the centerless polishing machine was designed and manufactured to polish cylindrical molding die surfaces with same polishing conditions. As the result of using cylindrical molding dies that made by this centerless polishing machine, the surface roughness of the glass plate formed using the slumping method with the polished molding die was below Ra = 20 nm. These results indicate that the surface roughness of the molding die had a small effect on the glass plate surface formed using the slumping method.

Speed Adjustment on Variable Frequency Induction Motor Using PLC for Automatic Polishing Machine

PT. ROFENTI KARSA TAMA is a ceramic industry that produces products in the form of ceramics from natural stone which are addressed in Winong GEMPOL Village - MALANG. To produce a perfect ceramic process requires absolutely reliable electrical and mechanical equipment. In an automatic system a frequency converter is used as a speed regulator, because in a manual system using a grinder, the capacity is only 0.57Kw (kilowatts), and the production effect is not good. Therefore, the purpose of this study is to design an automatic polishing machine using a PLC-based converter. Based on the PLC, the capacity is 5 or 5 Kw (kilowatts). This system can increase ceramic output and improve quality. In this case, assuming that the operator usually uses an automatic system to complete the work of the three operators, the polishing machine production costs can be reduced. Through system improvement, production quality can be improved, manual polishing operators can only produce 480 pieces per day, while the automatic system can produce 1,536 pieces. One day, the polishing operator will save production costs of Rp 2.7 million per month.