Die processing characteristics and matters needing attention
Mold processing refers to the processing of molding and billet tools, in addition to shear die and die cutting die. Usually, the mold has two parts: upper mold and lower mold.
The basic characteristics of precision die processing:
1. A pair of die with high processing accuracy is generally composed of concave die, punch die and die frame, and some may be multi-piece split module. Therefore, the combination of the upper and lower die, the combination of the insert and the cavity, and the combination between the modules require high machining accuracy. The dimensional accuracy of precision die often reaches the level of micron.
2. Complex Shapes and Surfaces Some products, such as automobile panels, aircraft parts, toys and household appliances, are made by combining a variety of curved surfaces. Therefore, the surface of the mold cavity is very complex. Some surfaces have to be treated mathematically.
3. The mass production of small molds is not mass production. In many cases, only one pair is produced.
4. Milling, boring and usually used for multi-mode machining
Notes for precision mold production and processing:
1, the raw materials must be fully dry according to the process requirements, without moisture, otherwise there will be silver grain on the surface after injection.
2, injection temperature, pressure, time and so on meet the requirements of process parameters card, injection speed should be strictly controlled, too fast injection speed will lead to poor adhesion between coating and matrix.
3. In the process of injection molding, release agents can not be used, especially those containing silicone oil, otherwise it will affect the adhesion of the coating.
4. The material should be cleaned after the middle shutdown to avoid the brittleness of injection products caused by the degradation of raw materials in the screw due to too long residence time;
5. The surface of injection molded parts shall not be polished and polished, so as not to affect the adhesion of coating and matrix.
6. Operators must wear clean cotton gloves in the process of injection molding to avoid contamination of the product surface after injection molding.
7. Internal stress control: large internal stress is not allowed in the product, and internal stress detection should be carried out after injection molding.
8, size control: length, assembly foot or assembly hole in accordance with the drawings and measuring requirements.
