1. Digest the drawings of plastic parts, understand the purpose of plastic parts, and analyze the technical requirements such as the manufacturability and dimensional accuracy of plastic parts. For example, what are the requirements of plastic parts in appearance, color transparency and usability, whether the geometric structure, inclination and insert of plastic parts are reasonable, the allowable degree of molding defects such as weld marks and shrinkage cavities, and whether there are post-treatments such as painting, electroplating, gluing and drilling. The dimension with the highest dimensional accuracy of plastic parts is selected for analysis to see whether the estimated molding tolerance is lower than that of plastic parts and whether the required plastic parts can be molded. In addition, we should also know the plasticizing and molding process parameters of plastics.
2. Digest the process data, and analyze whether the requirements such as molding method, equipment model, material specification and mold structure type proposed in the process specification are appropriate and can be implemented. Molding materials should meet the strength requirements of plastic parts and have good fluidity, uniformity, isotropy and thermal stability. According to the use of plastic parts, molding materials should meet the requirements of dyeing and metallization conditions, decorative performance, necessary elasticity and plasticity, transparency or opposite reflection performance, adhesion or weldability.
3. Determine whether the molding method is direct compression, casting compression or injection molding.
4. Choose molding equipment for molding according to the types of molding equipment, so be sure to be familiar with the performance, specifications and characteristics of various molding equipment. For example, for the injection machine, we should know the following contents from the specifications: injection quantity, mold locking pressure, injection pressure, mold installation size, ejection device and size, nozzle diameter and nozzle spherical radius, gate sleeve positioning ring size, mold maximum and minimum thickness, template stroke, etc. See related parameters for details. It is necessary to estimate the overall size of the mold and judge whether the mold can be installed and used on the selected injection molding machine.
5. Specific structural scheme. Determine the mold type and main structure, and choose the ideal mold structure. It is absolutely necessary to determine the ideal cavity number of the required molding equipment, so that the mold itself can work, meet the requirements of the manufacturability and production economy of plastic parts, ensure the geometric shape, surface smoothness and dimensional accuracy of plastic parts, ensure the low cost and high production efficiency of plastic parts, and save labor.