文档介绍：Injection Molding
The basic concept of injection molding revolves around the ability of a thermoplastic material to be softened by heat and to harden when cooled .In most operations ,granular material (the plastic resin) is fed into one end of the cylinder (usually through a feeding device known as a hopper ),heated, and softened(plasticized or plasticated),forced out the other end of the cylinder,while it is still in the form of a melt,through a nozzle into a relatively cool mold held closed under ,the melt cools and hardens until fully set- mold is then opened,the piece ejected,and the sequence repeated.
Thus,the significant elements of an injection molding machine e :1)the way in which the melt is plasticized (softened) and forced into the mold (called the injection unit); 2)the system for opening the mold and closing it under pressure (called the clamping unit);3)the type of mold used;4)the machine controls.
The part of an injection-molding machine,which converts a plastic material from a sold phase to homogeneous seni-liguid phase by raising its temperature .This unit maintains the material at a present temperature and force it through the injection unit nozzle into a mold .The plunger is bination of the injection and plasticizing device in which a heating chamber is mounted between the plunger and mold. This chamber heats the plastic material by c