Injection molding processing is one of the parts of injection molding, to meet the need to meet the five elements of injection molding, temperature, speed, pressure, location, time, these five elements determine the quality of molded products, control product quality is the key, Qualified products require control of the above factors. Injection molding often encountered in the quality of the problem comes from the five main points without control and caused by the quality of abnormal.
1, plastic mold processing process, the temperature is the first step in injection molding, the temperature can be divided into: drying temperature, material temperature, mold temperature, these are some of the most important factors. Dry temperature is to ensure the quality of the formation of the polymer in advance to ensure that the polymer dry and wet in a certain amount; material temperature is to ensure that the polymer plastic (melt) normal, and smooth filling, molding; The temperature is the skin size, appearance, molding cycle to consider the important conditions to control the impact of the product in the mold cavity in the cooling rate, as well as the appearance of the product quality.
2, the pressure is divided into: pressure, pressure, back pressure, mold clamping pressure, mold protection pressure, the top pressure. During the processing of plastic molds, the injection pressure is used to overcome the pressure loss of the melt from the nozzle-runner-gate-cavity to ensure that the cavity is filled; the packing is intended to reduce the pressure on the part due to excessive injection pressure Resulting in sticky mold burst or bending; pressure is to avoid the high-speed high-pressure state in the mold in the foreign body caused by the die is crushed; ejection pressure is to prevent the product from the mold surface caused by bad.
3, the speed is divided into: plastic mold processing process, the injection mold speed, melt temperature, loose speed, opening and closing mold speed, thimble forward and backward speed. Increased injection speed will increase the filling pressure, improve the injection speed can increase the flow length, uniform product quality to ensure product quality, high-speed injection for long process products, low-speed control product size; melt speed impact of plasticizing capacity, is plastic The higher the speed, the higher the melt temperature, the higher the plasticizing capacity; the loose speed is to reduce the melt capacity, so that the melting chamber pressure drop, to prevent the role of its outflow; open mold speed is To ensure that the machine production and operation of one of the important conditions; thimble forward and backward speed is to ensure the smooth demoulding of the product does not deform the product, the top crack.
4, the location can be divided into: plastic mold processing process, open mold position, the top out of the trip, measuring stroke, loose leg volume, injection stroke, buffer volume. The opening position is to ensure that the stripping part can be normal operation; out of the back stroke on the part of the spring reset to the role of the limit limit protection; measurement stroke is to ensure that there is sufficient plastic filling mold to ensure product quality; The role is to increase the volume of the melt in the measurement chamber, the internal pressure drop, to prevent the melt from the measurement chamber outflow; buffer to prevent the screw head and nozzle contact mechanical damage occurred, can control the accuracy.
5, the time is divided into: plastic mold processing, cooling time, sol time, drying time, cooling time, melt time, drying time, cycle, injection time, holding time. The time required for the molding of the product is to determine the size of the product; the holding time is to prevent the melt backflow, cooling shrinkage; cooling time to ensure product curing, to prevent deformation; melt time is to ensure that the melt full; To ensure that the product does not become elongated, bad and other factors.
Injection molding processing production often encountered bad reasons such as the appearance of defective product damage, wave marks, spray marks, scratches, etc., stripping, bubbles, stripping bad This series of problems are due to the above five factors.