There are many types of plastics, and many plastic materials have different melting times. Since plastics have no specific melting point, the so-called melting point is a temperature range in the molten state. The structure and composition of the plastic molecular chain are different, so the influence on its fluidity is also different. , Then it is also very important for manufacturers of injection molded parts to control the temperature during the processing of injection molded parts. Today, the editor of Xiehong Plastics will talk to you about the injection molding process and the temperature control of each process.

1. Mold temperature
Some plastic materials require higher mold temperature due to high crystallization temperature and slow crystallization speed. Some plastic materials require higher temperature or lower temperature due to the need to control size and deformation or demolding. For example, PC generally requires more than 60 degrees. In order to achieve better appearance and improve fluidity of PPS, the mold temperature sometimes needs to be above 160 degrees. Therefore, the mold temperature has an inestimable effect on improving the appearance, deformation, size, and rubber mold of the product.

2. Injection pressure
The melt overcomes the resistance required for advancement, which directly affects the size, weight and deformation of the product. Different plastic products require different injection pressures. For materials such as PA and PP, increasing pressure will significantly improve their fluidity. Injection pressure The size determines the density of the product, that is, the appearance of gloss. It has no fixed value, and the more difficult it is to fill the mold, the pressure of the injection molded part will increase.

3. Barrel temperature
The temperature of the molten material is very important, and the temperature of the injection cylinder used is only a guideline. Melt temperature can be measured at the nozzle or air jet method. The temperature setting of the injection cylinder depends on the melt temperature, screw speed, back pressure, injection volume and injection molding cycle. If you have no experience in processing a specific grade of plastic, please start with the lowest setting.

In order to facilitate control, the shooting cylinder is divided into zones, but not all are set to the same temperature. If the operation time is long or the operation is at high temperature, please set the temperature of the first zone to a lower value, which will prevent the plastic from melting and shunting prematurely. Before starting the injection molding, make sure that the hydraulic oil, hopper closure, mold, and injection cylinder are all at the correct temperature.

4. Melting temperature
The melt temperature plays a major role in the fluidity of the melt. Since plastics have no specific melting point, the so-called melting point is a temperature range in the molten state. The structure and composition of the plastic molecular chain are different, so the influence on its fluidity is different. Rigid molecular chains are obviously affected by temperature, such as PC, PPS, etc., while flexible molecular chains such as: PA, PP, PE, etc., the fluidity is not obvious by changing the temperature, so the reasonable temperature of injection molded parts should be adjusted according to different materials.