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| Learn about Injection Molding Machine (PART II) |
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I. Working process of injection molding machine
Plastic injection molding machine inject the plastic material into different plastic products with the help of mould. Though the injection molding machine differs a lot, the working procedure is basically the same. Below is working process the horizontal injection molding machine.
(1) Clamping and Locking
Injection molding process usually starts from mould clamping. The rate of moving template during the mould clamping process should meet the certain standard, to assure low pressure mold protection. On the one hand, the mould clamping runs in a steady way, to shorten the shock and prolong mould use life; On the other hand, it transfers to high-pressure locking station when the moving template and fix template get together. This station assures the mould with enough clamping tonnage, to prevent flash.
(2) Injection Seat Moving Forward
When the clamping device locks, the injection seat moves forward, to assure the nozzle and mould get together as a preparation for the injection station. After this process, the injection cylinder pushes the screw forward and the melting material is ejected into the mould at a certain pressure and speed. To assure the good quality of the plastic product, the mould must be kept in a certain pressure until the product congeals, which is called mould holding.
(3) Cooling and Pre-Plasticizing of Products
When the mould further cools down, the melting material begins to congeal. Mould holding is no longer needed when the melting material in the nozzle congeals. The product begins to cool down and falls into a pattern. At the same time, the screw drive device rotates the screw and the material runs into the barrel end and the mould.
(4) Injection device drawing back
Whether the injection device moves forward or back forward depends on the plastic processed. Some draws back during pre-plasticizing process, some before the plastic melting. Some injection process and product quality will be influenced if the material temperature in the nozzle is too low.
The injection device is often moved backward in the purpose of cleaning material.
(5) Mold opening and product injected
When the mould cools down, the clamping device opens the mould. With the cooperation of injection unit of injection molding machine and ejection device of mould, the product falls down automatically and prepares for the next production circuit.
II. Auxiliary Machines
Auxiliary machines refers to the related devices settled on or around the injection molding machine. This auxiliary machines can be devided into these kinds: (1) machines to process and supply material; (2) machines to pick and refine product; (3 )machines to adjust the temperature
(1) Heated Air Drier
Heated air drier is to dry the material before processing. It uses the hot air to bring away the water in the raw material.
(2) Grinder
Grinder helps to grind the defective products and the chipping can be reproduce to be the material.
(3) Automatic Loader
Automatic loader helps to inject the material in to the hopper and to the greatest extent, reduce the human resource and assure its safety.
(4) Chiller
Chiller is to reduce water temperature and keep the mould temperature within 3-50℃, to meet the needs of product process.
(5) Robot
Robot helps to pick the products from the cavity, to save the human resource and improve and increase the manufacture efficiency.
(6) Conveyor
Conveyor helps to convey the products to a certain place, to save human resource and realize automated production. |
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China
