Injection molding is one of the aspects of injection molding. It meets the five essential factors of injection molding, temperature, speed, pressure, position and time. These five factors determine the quality of the molded product. The key to controlling the quality of the product is this, a qualified product. The control of the above factors is required.
1.temperature is the first step of injection molding, temperature can be divided into: drying temperature, material temperature, mold temperature, these are some of the most important factors. The drying temperature is to dry the polymer in advance to ensure the molding quality, to ensure that the dry and wet of the polymer are in a certain amount; the material temperature is to ensure the plasticization of the polymer is normal, and the mold is smoothly filled and molded; the temperature of the mold is produced. Important conditions for skin size, appearance, and molding cycle considerations.
2.the speed is divided into: injection speed, melt temperature, loosening speed, opening and closing mold speed, ejector forward and backward speed. The increase of injection speed will affect the filling pressure increase, the injection speed will increase the flow length, the product quality will ensure the product quality, the high-speed injection is suitable for long-flow products, and the control product size at low speed; the melt speed affects the plasticizing ability, which is plastic The important parameter of the quality, the higher the speed, the higher the melt temperature, the stronger the plasticizing ability; the loosening speed is to reduce the melt specific volume, so that the internal pressure of the melting chamber is reduced to prevent its outflow; the opening and closing speed is One of the important conditions for ensuring the production and operation of the machine; the ejector forward and reverse speed is to ensure that the product is smoothly demolded without deforming the product and cracking.
3.Pressure is divided into: injection pressure, pressure holding, back pressure, mold clamping pressure, mold protection pressure, and ejection pressure. The injection pressure is used to overcome the pressure loss of the melt from the nozzle-flow path-gate-cavity to ensure that the cavity is filled; the pressure is to reduce the sticking of the part due to excessive injection pressure or Bending; being pressed to avoid foreign matter in the mold under high-speed and high-pressure conditions, causing the mold to be crushed; the ejection pressure is to prevent the product from being detached from the mold surface and causing defects.
4.The position can be divided into: mold opening position, ejection time, measuring stroke, loose leg amount, injection stroke, and buffer amount. The mold opening position is to ensure the normal operation of the demoulding take-up; the ejector retracting stroke has the effect of partial spring reset on the ejection limit protection; the metering stroke is to ensure that there is enough plastic filling mold to ensure the product quality.
5.time is divided into: cooling time, sol time, drying time, cooling time, melting time, drying time, cycle, injection time, pressure holding time. The molding of the product requires a certain period; the injection time determines the size of the product; the holding time is to prevent the melt backflow, cooling shrinkage; the cooling time ensures the product solidifies and prevents deformation; the melting time is to ensure the melt is sufficient; the drying time Ensure that the product does not become elongated, bad and other factors.
In the injection molding production, there are often unfavorable causes such as damage to the appearance of defective products, wave marks, spray marks, scratches, etc. The series of problems such as peeling, bubbles, and film removal are all affected by the above five factors.