The main process parameters of injection molded parts are summarized into several categories which include: barrel temperature, melt temperature, injection mold temperature, injection pressure, these four factors. Without the influence of these four factors, the injection molding process would not be possible to talk about. From the above analysis, we can see the importance of temperature to the injection molding process, and the important role of injection pressure to the injection molding. The following is an analysis of each element of the injection molding process, which can help us better understand the process and results of the injection molding process.
1. Barrel temperature of injection molding process
Effective control of barrel temperature is an important part to ensure the quality of injection molding supplies. The temperature setting of the injection cylinder depends on the melt temperature, screw speed, back pressure, injection volume and injection part cycle. If you are not experienced in processing a particular grade of plastic, start with the lowest setting. Injection cylinders are divided into zones for ease of control, but not all are set to the same temperature. When the barrel temperature is low and away from the setting, you should ramp up quickly, and when the barrel temperature is close to the setting, you should ramp up slowly. Before making the injection mold start, make sure that the hydraulic oil, hopper closers, injection mold and injection cylinder are all at the correct temperature.
2.Injection molding processing melt temperature
It is important to know that the melt temperature plays a major role in the fluidity of the melt, and the specific melting point should be controlled by yourself. As the plastic does not have a specific melting point, the so-called melting point is a molten state of the temperature band. Molecular chain is also one of the reasons, the structure and composition of the plastic molecular chain is different, so the impact on its liquidity is also different, rigid molecular chain by the temperature is more obvious, such as PC, PPS, etc., and flexible molecular chain such as: PA, PP, PE and other liquidity by changing the temperature is not obvious, so according to the injection moulding raw material list to adjust the reasonable temperature of the injection molded parts.
3. Injection molding processing injection mold temperature
Some plastic materials need higher mold temperature due to high crystallization temperature and slow crystallization speed, which makes us have to consider the relationship between crystallization and mold temperature. Some due to the control of size and deformation, or mold release requires a higher temperature or lower temperature, so the temperature can change the appearance of the shape of the production injection mold, etc., such as PC generally requires more than 60 degrees, and PPS in order to achieve a better appearance and improve mobility, the mold temperature sometimes requires more than 160 degrees, thus the injection molding mold temperature to improve the appearance of the product, deformation, size, rubber mold aspects have nearly decisive role.
4. Injection pressure of injection molding process
This force is required by the melt to overcome the resistance to advance, this force will directly affect the size, weight and deformation of the product, and the mold temperature plays an almost decisive role. Different plastic products require different injection pressures, and the shape of the products of injection moulding shaped by different pressures is also very different. For materials such as PA, PP, etc., increasing the pressure will make its flow significantly improved, the injection pressure size determines the density of the product, that is, the appearance of glossy. On the other hand, some injection molded parts will be more difficult to fill with the injection mold, and the injection pressure increases.