How to understand the characteristics of plastic mold injection and improve service life?

Author: MULAN - Plastic Molding Manufacturer

1. The basic characteristics of mold injection molding ① High precision is required. A pair of molds is generally composed of a die, a punch and a mold base, and some of the molds can be multi-piece molds. Therefore, the combination of upper and lower molds, the combination of inserts and cavities, and the assembly of modules all put forward high requirements for machining accuracy.

The dimensional accuracy of precision molds often reaches μm level. ②Complicated shape and surface Some products, such as automobile panels, aircraft parts, toys, and home appliances, have a shape surface composed of multiple curved surfaces. Therefore, the surface of the mold cavity is more complicated.

Some surfaces must be treated mathematically. ③Small batch mold production is not mass production. In many cases, only one payment is generated.

④ There are many processes in mold processing, and various processes such as milling, boring, drilling, reaming, and tapping are often used. ⑤ Repeat the service life of the production mold. When the use of a pair of molds exceeds its service life, a new mold must be replaced, so the production of molds is often repeated.

⑥There are sometimes no drawings or data in the production of profiling molds, and the profiling process should be carried out in kind. This requires high simulation accuracy and no deformation. ⑦Mold materials are excellent, and the main materials of high-hardness molds are mostly high-quality alloy steels, especially high-life molds, commonly used Cry2, CrWMn and other materials.

These steels have strict requirements from rough forging, machining to heat treatment. Therefore, the establishment of processing technology cannot be ignored, and heat treatment deformation is also a problem that needs to be taken seriously in the processing process. According to the above characteristics, the processing requirements should be met as far as possible when selecting the machine tool.

For example, the function of the numerical control system must be powerful, and the machine tool must have high precision, good rigidity, good thermal stability and contour function. 2. How to improve the service life of the mold For users, improving the service life of the mold can greatly reduce the stamping cost. Factors affecting the service life of the mold are as follows: ① material type and thickness; ② whether to choose a reasonable mold gap; ③ structural form of the mold; ④ whether the material is well lubricated during stamping; , Titanium carbonitride; ⑦Alignment of the upper and lower turrets; ⑧Reasonable use of adjusting gaskets; Benchmarking, two-dimensional and three-dimensional surface margin inspection; ③ two-dimensional and three-dimensional profile rough machining, non-installation surface, non-working surface processing (including safety platform surface, bumper installation surface, pressure plate surface, side datum surface); ④ Before semi-finishing, the alignment of the side datum planes should ensure accuracy; ⑤Semi-finishing two-dimensional and three-dimensional profiles, finishing all kinds of installation working surfaces (including stopper installation surface and contact surface, insert installation surface and backrest, Punch mounting surface, chip knife mounting surface and support back surface, spring mounting surface and contact surface, various stroke limiting working surfaces, wedge mounting surface and back surface), various guide surfaces, guide holes, remaining reference holes, finishing height Semi-finished products on the reference surface, and record data; ⑥Inspection and evaluation of machining accuracy; ⑦Inlay technology of fitter; ⑧Before finishing, align with the reference plane of the technical reference hole, and check the remaining amount of the insert; ⑨Finishing section 2D, 3D , Side punching section and hole position, finishing reference hole and height reference, guide surface and guide hole;