模具设计外文翻译--注塑成型(5)

Injection moldingIn injection molding, plastic particles by neutral from hopper into heat barrel. When screw plunger will plastic particles slow advance, plastic is advancing can make the melting of heating chamber. Because the plunger moving forward, melting plastic oppression by opposite the mould of nozzle, sprue and hot word systems into a cavity. Mould keep cooling, thus mould once be filled, plastic began to solidify. For injection molding cycle begins, the four standard must satisfy: mold open, push rod back, start injection, transmission forward. When this standard has achieved, injection cycle with mold closed began. The process is usually required to quickly finish, near the end of the approaching. Mould work requirements low and depression closure. It is usually in the mold guide bar begins operation before, we must properly design position to prevent accidental damage mold. When the companion touch clamp mold, then melting plastic tonnage contact this is injected into the mould. Materials through the gate set into the mold runner system will materials, after passing to the gate. Sprue guide material into the mold cavity forming wanted parts. The injection process usually have rate control. If parts are almost full of cavity, injection control from rate controlling steering pressure control, called pressure-keeping cycle. Pressure must be kept until sprue place to avoid molten plastic solidification of backflow. The cooling time mainly depends on the part of wall thickness and materials. Injection products usually require fast cooling. Water usually through waterway into the mold speed up the cooling speed. In cooling cycle after part, sprue has solidification, plasticizing happen. Plasticizing is molten plastic injection of a good man and prepare the next process. Materials in the hopper through hopper neck began to enter a nitrogen-treated barrel. Hopper neck must keep cooling to prevent because nitrogen-treated barrel too hot to plastic particles melt together. Contains a nitrogen-treated barrel for shear molten material screw, it consists of three parts. The first part is inflows part, which promotes plastic ball forward movement and requirements for stove temperature high make plastic pellets softened. Threaded uniform depth and the deepest in this part. Th