Things to Consider in Plastic Injection Processes
Plastic injection
There are some critical points to be considered in order to produce better quality and error-free work while molding. By producing high quality work, molding professionals must consider 4 factors when doing this work. These are as follows:
- Melting Temperature of Plastic
- Flow Rate of Plastic
- Injection Pressure and Back Pressure
- Cooling Time and Rate of Plastic
Plastic Melting Temperature
Plastic melting temperature setting is an issue to be considered. For this, some factors need to be evaluated together. For example, the hive and nozzle temperatures make up the two temperature zones. These two temperature values must be at the desired level in order for the plastics transferred to the molds to flow.
Hive Temperature: The hive temperature must be between the melting point and the thermo-decomposition temperature. If this setting is high, a burr image may occur as the material will be more fluid. If the temperature is lower than the required level, the fluidity of the plastic will be slow and this will cause a wavy appearance on the product.
Nozzle Temperature: If the nozzle temperature is not at the desired level, then the performance of the product will be affected. If the nozzle temperature is high, then the plastic may melt and overflow inside the nozzle. This causes the material to burn and clog the nozzle in the long run.
Plastic Flow Rate
The heated plastic provides a good flow to the cavities in the mold. The flow rate determines the viscosity of the plastic flowing into the mold. If the holding pressure is high, overflow and anchor, if the pressure is low, the product will have a problem.
Injection Pressure and Back Pressure
The pressure ratio is defined as the force exerted by the rocket as it pushes the molten plastic into the mold. If this force is high, it may cause problems in the product as there will be excessive fluidity. When the pressure is low, bubbles and incomplete product may occur. Thanks to the back pressure, the plastic material in the sleeve is compressed well, that is, pressing in the opposite direction. If this pressure is too high, it can damage the material.
Cooling Time and Rate of Plastic
The cooling rate varies according to the type of product to be obtained. Some products require temperatures of 60-80 degrees, while cooling takes a long time. In some, products react to sudden cooling. This prevents the product from being produced in the desired size. In the plastic injection process, the cooling time and rates are very important for the desired product to be of high quality and error-free.
