Plastic mold processing refers to the processing of plastic molding and plastic blank making tools, consisting of two parts: upper mold and lower mold. Its basic characteristics are as follows:
(1) High precision requirements for processing
A set of molds is usually composed of a concave mold, a convex mold, and a mold frame, and some may also be composed of multiple assembled modules. So the combination of upper and lower molds, the combination of inserts and cavities, and the assembly between modules all require high machining accuracy. The dimensional accuracy of precision molds often reaches the micrometer level.
(2) Complex surface shape
Some products, such as car covers, airplane parts, toys, and household appliances, have a surface shape composed of multiple curved surfaces, making the mold cavity surface very complex. Some surfaces must be processed using mathematical calculation methods.
(3) Small batch size
The production of molds is not mass production, and in many cases, only one batch is produced.
(4) Multiple processes
Various processes such as milling, boring, drilling, reaming, and threading are always used in mold processing.
(5) Repetitive production
The use of molds has a lifespan. When the use of a mold exceeds its lifespan, a new mold needs to be replaced, so the production of molds often has repeatability.
(6) Copy machining
Sometimes in mold production, there are neither drawings nor data, and it is necessary to perform contour machining based on the actual product. This requires high imitation accuracy and no deformation.
(7) Excellent mold material with high hardness
The main materials for molds are often made of high-quality alloy steel, especially for high life molds, which are often made of martensitic steels such as Crl2 and CrWMn. This type of steel has strict requirements from rough forging, processing to heat treatment. Therefore, the formulation of processing technology cannot be ignored, and heat treatment deformation is also a serious issue that needs to be taken seriously in processing.