Rapid development of mold manufacturing technology has become an important part of modern manufacturing technology. Such as mold CAD CAM technology, mold laser rapid prototyping technology, mold precision forming technology, mold ultra-precision processing technology, technology that mold design using finite element method, boundary element method for dynamic simulation of flow, cooling, heat transfer process, mold CIMS technology, developed mold DNM technology and numerical control technology, covering almost all modern manufacturing technologies.
Modern mold manufacturing technology is developing in direction of accelerating information-driven, improving manufacturing flexibility, agile manufacturing and systematic integration.

 

High speed milling not only has high processing speed and good surface accuracy, but also has a lower temperature rise compared to traditional cutting (workpiece is only 3℃ higher) and has less thermal deformation, so it is suitable for temperature-sensitive thermal deformation materials processing such as Magnesium alloy. Because of small cutting force, it can be applied to processing of thin-walled and rigid parts. Reasonable selection of tool cutting amount can achieve a series of advantages such as hard material (HRC60) processing. Therefore, high speed milling processing technology is still a hot topic at present, it has developed towards higher agility, intelligence, integration, and has become third-generation molding technology.

From perspective of foreign electromachining machine tools, no matter from performance, process indicators, intelligence, and automation, they have reached a very high level. At present, new trends in foreign countries are conducting research and development of electric discharge milling processing technology (electric spark creation processing technology). This is a new technology to replace traditional cavity processing for forming electrodes. It uses high-speed rotating simple tubular electrodes for three-dimensional or two-dimensional contour processing (like CNC milling), so it is no longer necessary to manufacture complex formed electrodes, which is obviously a major development in the field of EDM.
At the same time as process of electrical discharge machining technology, safety protection technology in electrical discharge machining has received increasing attention. Many electrical machine tools have considered safety protection technology. At present, European Union has stipulated that machine tools without "CE" mark cannot enter European Union market, and at the same time, international market is paying more and more attention to safety protection technology requirements.
At present, main problem of EDM machine tools is radiation harassment. Because it has a greater impact on safety and environmental protection, international market is paying more and more attention to "green" products. As main tool for mold processing, EDM machine tool "green" product technology will have to solve problems in the future.

At present, mold software developed by scientific research institutes in universities in some countries such as Britain, United States, Germany, and China has features of intelligent, integrated, and manufacturability evaluation of new-generation mold CAD / CAM software.
A new generation of mold software should be established to summarize a large amount of knowledge from mold design practices. This knowledge has been systematically and scientifically organized, stored in a specific form as an engineering knowledge base and can be easily called by mold. With support of intelligent software, mold CAD no longer imitates traditional design and calculation methods, and under guidance of advanced design theory, it takes full advantage of experts in the field to enrich successful experience of knowledge, its design results must be reasonable and advanced.
New generation of mold software uses three-dimensional ideas and intuitive feelings to design mold structure. Generated three-dimensional structure information can be conveniently used for mold manufacturability evaluation of NC machining. This requires mold software to use 3D parametric feature modeling, forming process simulation, reach a relatively complete level and a high level of integration in NC machining process simulation, information exchange organization and management. Measuring level of software integration not only depends on whether functional modules are complete, but also whether these functional modules share same data model, whether a global dynamic database is formed in a unified manner to achieve comprehensive management and sharing of information, support entire process of mold design, manufacturing, assembly, inspection, testing and production .
Mold manufacturability evaluation function: Role of new generation of mold software is very important. It is necessary to screen multiple plans, evaluate rationality and economics of mold design process, and provide a basis of modification for mold designer.
New-generation mold software, manufacturability evaluation mainly includes mold design and manufacturing cost estimation, mold assemblability evaluation, mold part manufacturing processability evaluation, mold structure and forming performance evaluation.
New-generation software should also have assembly-oriented functions, because mold function can only be reflected through its assembly structure. After adopting assembly-oriented design method, mold assembly is no longer simply assembled one by one. Its data structure can not only describe mold functions, but also define assembly characteristics of interrelationships between mold components, and realize component association, thus effectively ensuring mold quality.

 

1. Laser rapid prototyping technology (RPM) has developed rapidly, China has reached international level and gradually realized commercialization. World's commercial rapid prototyping processes are mainly SLA (stereolithography), LOM (layered split manufacturing), SLS (selective laser sintering), 3D-P (three-dimensional printing).
Tsinghua University first introduced SLA250 (stereolithography or photosensitive resin laser curing) equipment and technology from 3D company in United States and carried out development and research. After several years of effects, it has been improved many times, perfected and launched "M-RPMS-type multifunction rapid prototyping manufacturing system" (with layered solid manufacturing-SSM, melt extrusion molding-MEM), which is China's independent intellectual property rights and the only system in the world with two rapid prototyping processes (national patent), which has a better performance-price ratio.
2. Moldless multi-point forming technology: Another advanced manufacturing technology that using of height-adjustable punch groups instead of traditional molds for sheet surface forming. Moldless multipoint forming system uses CAD / CAM / CAT technology as main means to quickly and economically realize automatic forming of 3D curved surfaces. Jilin University of Technology has undertaken national key scientific and technological research projects on moldless forming, has independently designed and manufactured moldless multi-point forming equipment with international advanced level.
Compared with the Massachusetts Institute of Technology in United States, University of Tokyo, and Tokyo Institute of Technology in Japan, this technology in China is in a leading position in practical application of theoretical research, and is currently developing in area of popularization and application.
3. The first domestic trial production of resin stamping dies was successfully applied. FAW Mould Manufacturing Co., Ltd. designed and manufactured 12 sets of resin stamping dies for trial production of new Xiaohongqi car. These 12 sets of resin stamping dies are large, complex inner and outer cover drawing molds for luggage, engine hood, front and rear fenders, left and right fenders, etc. Main features is that mold profile is based on main CAD / CAM processing model, using Swiss Ciba refined high strength Resin for casting, gap between male and female molds is accurately controlled by imported wax. Dimensional accuracy of mold is high, manufacturing cycle can be shortened by one-half to two-thirds, and manufacturing cost can be saved about 10 million yuan (12 sets of molds). It has opened a new way for China's car trial production in small batches, which is a domestic initiative. Experts from Ciba Refinery believe that it can reach international level in 1990s.

With development of precision molds, measurement requirements are getting higher and higher. Precision coordinate measuring machines have long been restricted by environment and are rarely used on production site. New generation of three-coordinate measuring machines basically have temperature compensation and use of anti-vibration materials to improve dustproof measures and reliability of environmental adaptability. It can be easily used in installation workshop to realize characteristics of on-site measurement.

 

Mold polishing technology is an important part of mold surface engineering, an important process for post-processing of mold manufacturing process. At present, domestic mold polishing equipment, abrasives and processes of Ra0.05μm can basically meet needs, but mirror polishing equipment, abrasives and processes of Ra0.025μm are still in exploration stage. With large-scale application of mirror injection mold production, mold polishing technology has become a key issue in mold production. Due to some problems in domestic mold polishing technology and materials, injection molds for point-and-shoot camera lenses, CDs, VCDs, and injection molds that require high transparency still rely on imports.
It is worth noting that polishing of mold surface is not only affected by polishing equipment process technology, but also by mirror surface of mold material. This has not been given enough attention, that is, polishing itself is restricted by mold material. For example, when 45 # carbon steel is used for injection molds and polished to Ra0.2μm, obvious defects are visible to naked eye. If you continue to polish it, you can only increase brightness, and roughness has no hope of improvement. Therefore, current domestic mirror mold often uses imported mold materials, such as Sweden's Yisheng 136, Japan's Datong PD555 can obtain satisfactory mirror degree.
Mirror mold material is not only a matter of chemical composition, but also more importantly, a series of advanced processes such as vacuum degassing, argon gas protection ingot, vertical continuous casting and rolling, and soft forging are required for smelting, so that a series of advantages such as less internal defects, finer particle size, higher dispersion, finer metal grains, and better uniformity are achieved in mirror mold steel to meet requirements of polishing to mirror mold steel.