1. Digest the drawings of plastic parts, understand the use of the parts, and analyze the technical requirements such as the craftsmanship and dimensional accuracy of the plastic parts. For example, what are the requirements of plastic parts in terms of appearance, color transparency, and performance, whether the geometric structure, inclination, inserts, etc. of plastic parts are reasonable, the degree of acceptance of welding marks, shrinkage holes and other forming defects, whether there is coating Assembly, electroplating, gluing, drilling and other post-processing. Select the scale with the highest dimensional accuracy of plastic parts for analysis, and see if the estimated molding tolerance is lower than that of the plastic parts, and whether the plastic parts that meet the requirements can be molded. In addition, it is necessary to understand the plasticization and molding process parameters of plastics.
2. Digest the process data, and analyze whether the molding method, equipment type, material standard, fixture structure type and other requirements proposed in the process task book are appropriate and whether they can be implemented. The molding material should meet the strength requirements of plastic parts, and have good fluidity, uniformity, isotropy, and thermal stability. According to the use of plastic parts, the molding material should meet the requirements of dyeing, metallization conditions, decoration function, necessary elasticity and plasticity, transparency or opposite reflection function, adhesiveness or weldability, etc.
3. Confirm the molding method: choose the direct pressing method, the casting method or the injection method.
4. Selection of molding equipment According to the variety of molding equipment, it is necessary to be familiar with the functions, standards and characteristics of various molding equipment. For example, for the injection machine, the following should be understood in terms of standards: injection capacity, clamping pressure, injection pressure, mold equipment size, ejection equipment and size, nozzle hole diameter and nozzle spherical radius, gate sleeve positioning ring size, The maximum thickness and minimum thickness of the fixture, template stroke, etc., see related parameters for details. To start to estimate the size of the mold, determine whether the mold can be installed and used on the selected injection machine.
5. Detailed structural scheme. Confirm the type of fixture, the main structure, select the ideal mold structure, confirm the necessary molding equipment, and the ideal number of cavities. Under the conditions, the mold itself can be satisfied with the operation of the plastic parts. The process skills and production economic requirements of the plastic parts must ensure that the plastic parts process skills are required. Parts, geometric shapes, surface finish and dimensional accuracy, economical requirements for production, low cost of plastic parts, high production efficiency, continuous operation of molds, long service life, labor saving.