Injection moldingIt is a specific cycle. There are five factors that affect injection molding: temperature, speed, pressure, position and time. These five process factors determine the quality of injection molding processing. The quality problems often encountered in the injection molding process are mostly caused by the abnormal quality caused by the five points that are not well controlled.

Temperature is the primary factor of injection molding, which can be divided into several key factors such as drying temperature, material temperature, mold temperature, etc. The drying temperature is the pre-drying of plastic materials to ensure its molding quality and ensure that the dryness and wetness of plastics are within a certain range; The material temperature is the normal plasticization, smooth filling and molding of plastics; Mold temperature is an important factor to be considered in the injection molding process. The size of injection mold temperature, appearance, molding cycle and other factors affect the cooling rate of the product in the mold cavity and the appearance quality of the product.

The second factor speed: speed is divided into injection mold speed, molten material temperature, mold withdrawal speed, mold opening and closing speed, and ejector pin forward mold withdrawal speed. The improvement of injection speed affects the improvement of mold pressure. Improving the injection molding speed can improve the flow rate, ensure the product quality, and ensure the product quality. High-speed injection is suitable for long-process products. The injection speed that controls the product size at low speed affects the plasticizing ability. It is an important parameter of plasticizing quality. The higher the speed is, the higher the melt temperature is, and the stronger the plasticizing ability is. In order to reduce the specific capacity of the melt and reduce the internal pressure of the melt, The opening and closing speed to prevent its outflow is an important condition to ensure the operation of machinery.

The third element is pressure: pressure is divided into injection pressure, holding pressure, back pressure, mold locking pressure, mold base protection pressure, and ejection pressure. The injection pressure is used to ensure the pressure loss of the melt from the nozzle - runner - gate - cavity to ensure that the cavity is full; The pressure-holding method is used to reduce the breakage or bending of the adhesive mold caused by excessive injection pressure of the parts; The pressed method is used to prevent the mold from cracking due to foreign matters under high speed and high pressure; The top pressing method is used to prevent the product from leaving the mold surface and causing mold damage.

The fourth element is position: position can be divided into mold opening position, ejection modulus, measurement modulus, ejection modulus and buffer modulus. The mold opening position is to ensure that the demoulding parts can work normally; The ejection stroke is the protection effect of spring partial return on ejection limit; The ejection stroke is to ensure that there is enough plastic to fill the mold to ensure product quality; The jacking stroke is to increase the specific capacity of the melt in the metering chamber, reduce the internal pressure, and prevent the melt from flowing outward from the cavity; The jacking stroke is to prevent the mechanical damage accident caused by the contact between the screw head and the nozzle.

The fifth element is time: time is divided into cooling time of plastic products, plastisol time, plastic drying time, cooling time of plastic products, melting time, drying time, cycle time and pressure holding time. Forming products need a specific cycle; The injection time determines the size of injection molding products; Pressure maintaining is to prevent the melt from flowing backwards; Cooling and shrinkage effect; The cooling time is to ensure the solidification of plastic products and prevent product deformation; The spraying time is to ensure sufficient products; The drying time is to ensure that the products will not grow longer and have poor quality.