7) Most of the injection cycle are required to adjust the rotational momentum of the screw village, so that when the screw injection is finished, most of the small amount of cushion plastic, so as to ensure that the screw to achieve effective propulsion time and maintain a fixed shooting pressure. The cushion material of small injection molding machine is about 3mm; Large injection molding machine is 9mm. No matter how big the screw pad is used, it mustremain the same. Now the size of screw cushion material can be controlled within 0.11mm.
8) The rotation speed of the screw significantly affects the stability of the injection molding process and the heat applied to the plastic. The faster the screw rotates, the higher the temperature. When the screw rotates at a high speed, the friction (shear) energy transmitted to the plastic increases the plasticizing efficiency, but also increases the inhomogeneity of the melt temperature. Because of the importance of the screw surface speed, the screw rotation speed of large injection molding machine should be less than that of small injection molding machine, because the shear heat energy generated by the large screw is much higher than that of the small screw at the same rotation speed. Because the plastic is different, the screw rotates at different speeds.
9) The evaluation of syringe molding machines is usually based on the amount of PS that can be injected per injection, which may be measured in ounces or grams. Another arrangement system is based on the product of molten colloid injected by injection molding machine
10) An injection molding machine is usually evaluated by the amount of PS (in pounds/kg) that can be uniformly melted within an hour or heated to a uniform melt temperature, known as plasticizing capacity
11) To determine whether the quality of the product can be maintained throughout the production process, a simple formula for yield and plasticizing capacity can be used, as follows: T =(total injection shooting gX3600)÷(injection molding machine plasticizing amount kg/hX1000) T is the lowest cycle time, such as the cycle time of the mold is lower than t value, the injection molding machine can not fully plasticize the plastic, in order to achieve even fusion adhesive viscosity, so the injection molding parts often appear deviation. Especially for thin wall or precision tolerance molding quality, the amount of injection and plasticizing must be compatible.
12) The rate at which plastics decompose depends on temperature and time. Plastic, for example, breaks down after being kept at high temperatures for a long time; But at lower temperatures, it takes longer to decompose. So the retention time of plastic in the injection cylinder is very important.
The actual retention time can be determined experimentally by measuring the time required for colored plastics to pass through the injection cylinder, which can be roughly calculated by the following formula: Please note that some plastics stay in the injection cylinder for longer than the calculated time because they can coalesce in the injection cylinder.
