1. Obtain: Whether the "mold opening stroke" and "mold support stroke" are enough to take out the finished product depends on the mold and the finished product. The opening stroke of the mold should be at least twice the height of the finished product in the direction of mold opening and closing, and should include the gate length. The stroke of the mold support should be sufficient to launch the finished product;

2. Shoot well: "Screw compression ratio" and "shooting pressure" are determined by plastic. Some engineering plastics require a higher injection pressure and a suitable screw compression ratio design to obtain better molding results. Therefore, in order to make the finished product shoot better, the injection pressure and compression ratio should also be considered when selecting the screw. In general, a screw with a smaller diameter can provide a higher injection pressure.

3. Choose the appropriate model: the model and series are determined by the product and plastic. Because there are many types of injection machines, it is necessary to correctly determine at the beginning which injection machine or series should be used to produce this product, such as general thermoplastic or bakelite raw materials or polyester raw materials, they are single color, double color, multi Color, sandwich color or mixed color. In addition, some products require high stability (closed loop), high precision, high rate of fire, high ignition pressure or rapid production (multi-loop). The appropriate series must be selected for production.

4. Coordination: According to the size of the mold, determine whether the "large column inner distance", "mold thickness", "small mold size" and "template size" of the machine are suitable to confirm whether the mold can fit. The width and height of the mold should be less than or at least one side should be less than the distance between the large columns. The width and height of the mold are preferably within the size range of the template; the thickness of the mold should be between the thickness of the injection molding machine. The width and height of the mold should meet the small mold size recommended by the injection molding machine, and it is too small; so far, the specifications of the mold clamping device have been initially determined, and the tonnage of the model has been roughly determined. Then, the following steps must be performed to confirm which injection unit has a screw diameter that meets the requirements.

5. Shoot fast: and confirm the "shooting speed". Some finished products require high injection rate and high speed to be stable, such as ultra-thin finished products. In this case, it may be necessary to confirm whether the machine's injection rate and injection rate are sufficient, and whether it is necessary to match the pressure accumulator, closed loop control and other devices. In general, under the same conditions, a screw capable of providing a higher ignition pressure usually has a lower ignition rate. On the contrary, a screw capable of providing a lower ignition pressure usually has a higher ignition rate. Therefore, when selecting the screw diameter, it is necessary to consider and select the injection amount, injection pressure, and injection rate (injection speed).

6. Full injection: According to the weight of the finished product and the number of die holes, determine the required "injection amount" and select the appropriate "screw diameter". When calculating the weight of the finished product, the number of die holes (a few holes per die) should be considered; for stability, the injection volume should be greater than 1.35 times the weight of the finished product, that is, the finished product weight should be within 75% of the injection volume;