1.Material tube temperature:
The temperature at which resin is melted is usually achieved by heating with a power source. The temperature increase of plastic from solid to molten state is mainly caused by the temperature of the material tube and the shear heat provided by the rotation of the screw. In theory, the ratio of energy they provide is 3:7.
In terms of material tube temperature setting, different temperatures are set according to different raw materials, among which the temperature at the front end (nozzle area) is slightly lower than that at the middle end to prevent runny nose; The back end (feeding area) should also be lower than the middle end, 20-30 degrees lower than the front end, mainly to prevent abnormal feeding. Another advantage is that the exhaust will be better, and the product is less likely to have defects such as silver wires.
2. Mold temperature:
Set the mold temperature recommended by the raw material manufacturer according to different raw materials. Mold temperature can affect the crystallinity of the resin, which in turn affects the stability of the product (crystalline material). Another benefit of mold temperature is that it can help the raw materials flow more smoothly in the mold cavity.
The mold temperature affects the flow of the melt and the cooling process of the melt, thereby affecting the glossiness of mirror products, and can also greatly affect the glossiness of bite pattern products. Of course, it also has a significant impact on the degree of deformation. In short, there are many benefits.
3. Oil temperature:
Hydraulic injection molding machines generally use hydraulic oil to transmit pressure, and its temperature is the oil temperature (not the oil of deep-fried dough sticks, hehe....) Suitable oil temperature can greatly extend the service life of the machine and improve stability.
The first reason is that the oil seal will age;
The second reason is that the expansion coefficient of the oil seal is far different from that of the oil cylinder, which is also the main reason why hydraulic machines leak oil.
So now there are also a few injection molding machines that use rare earth metal oil seals. The sealing rings of injection molding machine oil cylinders are mostly U-shaped rings made of PU material. Due to the characteristics of PU plastic, its normal operating temperature is around -30 to 80 degrees.
If the oil temperature exceeds 55 degrees, due to the heat conduction effect of the oil cylinder during operation, the temperature of the sealing ring itself will exceed 55 degrees when it is stationary, and frictional heat will be generated when it is in motion. The surface temperature of its contact surface with the workpiece will exceed 100 degrees when it is in motion. Long term operation will greatly shorten the life of the sealing ring, and the material on the working surface of the sealing ring will accelerate aging and deformation.
Therefore, it is best to maintain the injection molding oil temperature at a lower level to prevent damage to the sealing ring. Although the optimal working temperature for hydraulic oil is around 45 degrees, maintaining the oil temperature at around 35 degrees does not significantly affect the performance of the hydraulic system. But it cannot be too low, as it will affect the operation of the hydraulic system.
