Papers by Keyword: Demolding

Abstract: For the net shape forming of composite products with structure of SB/CF-EP (steel backing/carbon fabric reinforced epoxy) lining, the demolding is difficult. Aiming to net shape forming of transmission screw nuts with structure of SB/CF-EP, a new solution was proposed in which the high-strength casting wax was used as the release agent. A basic demolding experiment was designed and comparative demolding experiments were conducted for three different conditions: wax and grease as release agents and no agent. The influences of different agents and agent thickness on demolding force, product sizes and surface quality were studied. In comparison with grease and no release agent the demolding force for wax was reduced by 91.6% and 98.0% respectively. The product shrink could be compensated by controlling the wax thickness. By using wax release agent, the fabrication of transmission screw nuts with SB/CF-EP lining was successfully completed.

Abstract: Gear tooth profile modification can be featured to improve working stability of gear equipments, abate noise and vibration, enhance loading ability and prolong usage life of the gears. Fine forged spur bevel gear are formed with molds, so it is economical to modify the gears by means of modifying mold cavity. Whether the modified gears can be separated from the mold with easiness is proposed to be the basic criterion of gear tooth profile modification design. Near the big ends and tooth roots is mainly the area which affects demolding after modification. According to the modified gear configuration, mathematical model is built to calculate the demolding check at any modification points on the fine forged spur bevel gear profile. And a corresponding program is developed, which is the main tool for the gear tooth profile modification design, and practical calculation has carried out.

Abstract: Micro hot embossing process is a cost-effective method for parallel replication of polymer microstructures. To study the effect of hot embossing and demoulding parameters on the replication accuracy of the polymer microstructure, densely patterned and high-depth channels on 50mm×50mm polymer substrates were fabricated by hot embossing in this paper. Experimental results showed that the replication accuracy of the microstructure increased with the increasing of hot embossing temperature and the thickness of polymer substrates. It can be found that demoulding became more difficult when replication accuracy increased. The reason was that higher replication accuracy resulted in larger contact area between the replica and the embossing mold. The demoulding problem could be solved by rising demoulding temperature. However, overhigh demouding temperature (110°C) would lead to round corners at the edges of the ribs. Experimental results also showed that very small channel widths and depths errors (less than 1.2%) of the microstructures with 2mm thickness substrates could be achieved, when embossing and demoulding temperatures were set to 120°C and 100°C, respectively.