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This mechanical analyses the principle of vertical injection molding machine

  Injection molding machine can have a molding complex, the size is accurate or texture is fine and close with a metal insert plastic products, widely used in national defense, electrical, automotive, transportation, building materials, packaging, agriculture, culture and education of health and People's Daily life. Injection molding process of all kinds of plastic processing and has good adaptability, high production capacity, and easy to realize automation. Today with the rapid development of plastic industry, injection molding machine both in quantity and variety on occupies an important position, the total number of production, accounting for 20% - 30% of the whole plastic molding equipment, thus become the fastest growing in the plastic machinery, one of the largest number of models in production. According to relevant statistics, China's export in 1996-1998 injection molding machine 8383 units (sets), import injection molding machine 42959 units (sets), of which 1998 years China has reached 20000 sets of injection molding machine production, its sales accounted for 42.9% of machines in total sales. For the working principle of injection molding machine and injection syringe are similar, it is with the help of a screw or plunger of thrust, will has good plasticizing molten state (that is, the viscous flow state) plastic injection into the closed good cavity, after curing finalize the design the product process. Injection molding is a process of circulation, each cycle mainly includes: quantitative feeding - plasticizing, injection pressure, melt filling mold cooling - and pick-up. After take out the plastic mold closing again, for the next cycle. Injection molding is a process of circulation, each cycle mainly includes: quantitative feeding - plasticizing, injection pressure, melt filling mold cooling - and pick-up. After take out the plastic mold closing again, for the next cycle. 

Injection molding machine generally include injection device, clamping device, hydraulic system and electric control system and other parts. 

  Injection device, its main function is to make plastic plastic evenly into molten state, and with enough pressure and speed of injecting molten material into the mold. It is mainly composed of plasticizing unit (barrel, screw or plunger, nozzle, etc.), hopper, screw transmission device (oil motor, etc.), injection oil cylinder, mobile oil cylinder injection, etc. 

  Clamping device: it is to ensure that the molding mold reliable closed and realize opening and closing action and parts of out products. Because of molten material at high pressure injection mold cavity, in order to lock the mold did not lead products flash or affect products quality, will exert enough clamping force on the mold (namely mould clamping force). Clamping device includes a fixed template template before and after, after moving template, wallboard, connecting rod, the clamping oil cylinder, ejection mould device of oil cylinder, etc. 

Hydraulic system and electrical control system: it is to ensure that the scheduled injection molding machine according to process requirements, such as pressure, velocity, temperature, time, etc.) and the action program set up by the accurate effective work motivation and control system. 

  General screw injection molding machine molding process is: first, add the granular or powdered plastic barrel, and with the rotation of the screw and barrel outer wall heating make plastic molten state, then the machine forward, clamping and injection nozzle with mold gate way, then to the injection cylinder pressure oil of our factory, make the screw to move forward, thus at high pressure and fast speed will be within the closed mold injection melting temperature is low, after a certain time and pressure maintenance (also known as the holding), cooling, make its curing, can open mold to take out the products (the holding of the purpose is to prevent cavity in the reverse flow of the molten material, supplementary material within the cavity, and ensure that products have a certain density and size tolerance). Injection molding is the basic requirement of plasticizing, injection and molding. Plasticizing is the precondition for the implementation and ensure the quality of molding products, to meet the requirements of molding, injection must ensure that there is enough pressure and speed. At the same time, because of the high injection pressure, and accordingly a high pressure in the cavity (average pressure within the cavity is in commonly between 20 ~ 45 mpa), so you must have enough clamping force. Thus, mould device of injection device and is the key to the injection molding machine parts. 

The action of injection molding machine program: 

  Close to closing, the nozzle forward to injection, the holding to forecast model, loose back to the nozzle back to cooling, mould, ejection to return a needle, open the door. 

Injection molding machine operating items: injection molding machine project including control keyboard operation, electrical control system and hydraulic system operation in three aspects. Movement and feeding movement respectively by injection process, injection pressure, injection rate, ejection type choice, cylinder paragraphs temperature monitoring, the adjustment of the injection pressure and back pressure, etc 

  To the evaluation of plastic products, mainly has three aspects: the first is the appearance quality, including integrity, color, luster, etc; The second is the accuracy of the size and the relative position between; The third is to use the corresponding physical properties, chemical properties, electrical properties, etc. The quality requirements and according to different products use occasions, the requirements of the scale is different. The defect of products mainly lies in the mold design, manufacture precision and degree of wear and tear, etc. But, in fact, plastic processing factory technical personnel often suffer from mould defects face with technology means to offset the problems and difficulties of washout. 

  Production process in the process of adjustment is the necessary way to improve product quality and production. As the injection molding cycle is very short, if the process conditions to master is bad, waste will be endless. In the adjustment process, change one the best conditions for observation a few times more, if the pressure, temperature, time, all together, very easy to cause confusion and misunderstanding, is out of the question and I don't know dangyang. Adjust the process there are a variety of measures and means. For example: solve the problem of products note discontent is more than a dozen possible solutions, to choose the solution problem of one, two main problems, to solve the problem. In addition, still should pay attention to the relationship between syndrome differentiation in the solution. For example, products in the sag, sometimes to improve material temperature, sometimes to lower temperature; Sometimes to increase capacity, or to reduce the shoes. To admit that the feasibility of reverse measures to solve the problem. 

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