Mold is the necessary process equipment for plastic molding production. In the past, mold design mainly depended on the experience of technicians. The mold processing and manufacturing relies heavily on the operating skills of workers. Therefore, the mold design level is low, the processing quality is poor, the production cycle is long, the service life is short, and the replacement of new products will be disturbed by mold problems. With the continuous development of plastic molding technology, the importance of molds is increasingly recognized by people, and some people even put forward the creed that "there is no product without molds". In the past ten years, the plastic molding and processing industries at home and abroad have invested a lot of money and research in improving and improving mold design and manufacturing technology, and have achieved many achievements, which can be summarized as follows:
(1) Innovation of mold processing technology
In order to improve the machining accuracy of the mold and shorten the mold processing and manufacturing cycle, the mold industry has widely used profiling processing, such as electrical machining, CNC machining and other advanced technologies, as well as coordinate boring, coordinate milling, coordinate grinding and three-coordinate measuring machines. measuring equipment.
(2) Various new mold materials are widely used
In the process of mold design and manufacturing, the selection of mold materials is a very important issue. Whether the material selection is reasonable will directly affect the processing cost, service life and quality of plastic products of the mold. Many new mold steels with good performance, good processing performance and small heat treatment deformation have been developed, such as pre-hardened steel, new quenched and tempered steel, maraging steel, precipitation hardened steel and corrosion-resistant steel.
(3) The degree of standardization and specialization of mold parts is getting higher and higher
Mold processing is a typical single-piece multi-variety production. The standardization of mold parts and the specialized production of mold parts are one of the important ways to shorten the mold processing cycle and reduce the cost of mold production.
According to foreign statistics, after the specialized production of mold standard parts, the cost of molds can be reduced by 50%. Various industrial countries attach great importance to the standardization and specialization of mold parts. The degree of mold standardization in the United States and Japan has reached 70%, and specialized production The degrees are 90% and 70%, respectively.
The degree of standardization of domestic molds is only about 20%. Specialized production has not started long, but relevant departments are strengthening this aspect.
(4) The application of CAD/CAM technology is becoming more and more common
At present, plastic mold CAD/CAM technology research is being carried out extensively at home and abroad, and many software systems have been developed that have been applied in extrusion and injection molding. As far as the injection mold CAD/CAM technology is concerned, the use of CAD can automatically complete the process analysis of plastic products, flow analysis and thermal analysis of plastic melt during the molding process, and various calculations related to injection molds with the participation of people. Design and drawing work; the use of CAM computer can control CNC machine tools to automatically complete the processing tasks of mold parts; if CAD/CAM is integrated, the entire injection mold design and manufacturing work can be completed automatically by the computer with the participation of people. Injection mold CAD/CAM technology is widely used in industrialized countries, and commercialized system software is sold in the market. A lot of research and development work has also been carried out in China, and some results have been achieved, but the application and promotion of this technology Compared with foreign countries, there is still a certain gap, which needs to be further improved and perfected.