Wuhan handern Injection Molding Principles and Features One, injection molding principle

日期:2020/6/29 8:30:11 / 阅读: / 来源:本站

Wuhan handern Injection Molding Principles and Features
One, injection molding principle
      Injection molding refers to placing the raw materials for injection (generally granular plastic) in a heated material to be heated. After compression molding, the screw or plunger is used to increase the pressure, so that the body is injected into the mold of the desired shape through the nozzle at the end of the material to fill the mold cavity. After cooling and shaping, the mold is demolded to obtain the product with the desired shape. This process is usually achieved by injection molding machines and nuclear tools. We call plastics, injection molding machines and molds the three elements of injection molding, and the pressure, temperature and cycle of molding are called the three principles of injection molding. When evaluating its importance, the former is 30% and the latter is 70%, which means that controlling process conditions is the most important. www.handern.com Meltblown non-woven equipment
      The requirements for injection materials are that they can melt and flow under the action of heat and pressure, so most of the thermoplastic materials and hot round materials can be applied to the injection molding process. The injection molding of thermosetting materials has been mediated in Chapter 8, Section 3, and this chapter only deals with injection molding of thermoplastics. www.handern.com Meltblown non-woven equipment
Second, the basic principles of injection molding
       The operation of the injection machine is as follows: the resin is added to the hot material feed device. The material is provided with a column or screw driven by an injection cylinder, which can send the material to the heating area of the barrel, where the material is softened and heated to the required temperature. When the plunger is pushed into the screw, the thermoplastic melt is injected into the closed mold under the pressure, and the injection molding wave is fixed on the mounting plate of the injection machine. The lock system ensures the closing of the injection mold and provides the necessary force for the operation program machine that can control the injection cycle. The injection machine is equipped with a time section. www.handern.com Meltblown non-woven equipment
3. Features of injection molding machine
      At present, according to the structural characteristics of the injection molding machine, it can be generally divided into a plunger injection molding machine and a screw injection molding machine. The cycle of the screw injection molding machine begins with the injection mold closed, and then the nozzle closely adheres to the injection mold. Under the action of the pressure generated by the hydraulic cylinder, the screw is in the front position, and the end of the screw closes the nozzle. Therefore, the plastic melt does not enter the mold when the screw starts to rotate. When the screw continues to rotate, the pressure at the front of the material rises, and the rod moves backward against the pressure of the cylinder. www.handern.com Meltblown non-woven equipment After this, the nozzle hole opens and the melt enters the mold. After filling the mold, the pressure in front of the screw gradually exceeds the pressure of the cylinder, and the rod that rotates in the feed moves backward. When the cylinder reaches the specified pressure, the screw stops rotating. Under the pressure of the cylinder, the rod works like a column, and a small amount of body is sent into the mold to compensate for the shrinkage of the heat-type material in the pole. During the pressure holding period, the screw moves in the direction of the nozzle. At the end of holding pressure, the end of the release lever approaches the nozzle and closes the nozzle hole. Like the usual injection, the product is released from the mold after cooling. www.handern.com Meltblown non-woven equipment
       One of the characteristics of screw injection is that the manufacture of thermoplastics, filling and partial cooling of products are carried out simultaneously. The styling of the material is carried out between the material and the end of the screw (generally made into a spiral cone) and the material. A high shear stress can be generated in the gap of this cone-shaped body before the nozzle, which ensures that the body can be further homogenized and heated before entering the mold.

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