Variotherm Mould Technology for the Production of Plastic Gears: A key technology for plastic gears with homogenous morphology for high performance applications

摘要

The material properties and the fatigue strength of plastic gears are mainly influenced by the injection moulding process. For semi crystalline plastics a higher mould temperature increases the degree of crystallisation. This leads to a higher strength, hardness, stiffness and abrasion resistance of the part. One of the resulting influences on plastic gears is therefore a bigger number of load cycles while the coefficient of friction is unchanged. [3] For that reason a high mould temperature should be aspired in the production of gear wheels in order to receive the best properties. Nevertheless it is not common practice to use higher mould temperatures in the current manufacturing processes due to the economic disadvantage of significant longer cooling times. To get high crystalline parts in short cycle times a high mould temperature during the injection of the hot melt and an efficient temperature control system is essential. [1] This is realized with optimized contour close channels in a 3-D printed LaserCUSING insert. This technology leads to a homogenous growth of crystals and even shorter cycle time than the conventional process.