The Status and Development Trend of Rapid Molding Technology

Rapid tooling technology is a fast, convenient and practical tooling manufacturing technology. It is produced with the development of industrial production and has been widely valued by product developers and molders. The research on it is in the ascendant, and new technological achievements continue to emerge, presenting a vigorous development trend and having a strong vitality.显 The salient features of rapid mold making technology are: short molding cycle, simple process, easy promotion, low mold making cost, accuracy and lifespan to meet certain specific functional requirements, comprehensive economic benefits are good, especially suitable for new product development and trial production , Process validation and functional verification, as well as multi-species and small batch production. 
In foreign countries, research on rapid tooling technology has a history of several decades. Many industrialized countries, such as many companies in the United States, the United Kingdom, Japan, and Switzerland, have conducted in-depth research on various types of rapid dies, and Many fields are applied. Since the 1960s, China has also begun to recognize the practical value of rapid tooling and has invested in research. In the 1970s, with the introduction of the four modernizations, rapid tooling technology gained the attention of government departments and it also developed to some extent. However, in the planned economy, the development speed was relatively slow. Since the reform and opening up, the competition between enterprises has been intensifying, and the product development cycle has become shorter and shorter. This has provided development opportunities and room for rapid tooling. In the 1980s, rapid tooling technology played an important role in the development of China's economy, especially the development of the automobile industry, and achieved brilliant achievements. However, with the continuous emergence of modern high-tech and the improvement of people's aesthetics, the concept of product quality and sample quality at the development stage has undergone great changes, and traditional rapid molding techniques have been severely challenged. Since the early 1980s, the author has been engaged in the application research of rapid tooling technology. Now I discuss some of my own opinions on the status quo and development trend of China's rapid tooling technology. The development of rapid moldmaking technology
1. The development of traditional rapid tooling technology is severely constrained. Traditional rapid tooling techniques can be summarized as follows: 1. Low-melting point (Bi-Sn) alloy molding techniques; 2. Zinc-based alloy molding techniques; 3 Composite molding techniques; 4. Spray forming molding techniques; 5. Electroforming molding techniques; 6. Copper-based alloy molding techniques. Most of the traditional rapid tooling techniques rely on the use of copying methods (such as casting, spraying, electroforming, and composite material casting) for the main working parts of the mold (convex, concave, or cavity, core). of. Therefore, the model (mother) becomes the key to the rapid manufacturing of the mold. The accuracy of the model directly determines the accuracy of the mold. Most of the traditional model production methods use the original or manual knocking, manual engraving, and the process is backward, the precision is very low, directly affecting the accuracy of the rapid mold. Therefore, people often think that the rapid mold precision is low, the so-called fast is at the expense of accuracy, and can only be used in applications where the accuracy requirements are low. This kind of understanding and understanding clearly has unfairness. The traditional rapid tooling technology has high copying accuracy. As long as the model accuracy is solved, the precision of the tooling will naturally be solved. Therefore, how to improve the accuracy of the prototype has become the key to the rapid development of rapid tooling technology, and it is also an important issue that we must solve. 2. The traditional rapid die market is shrinking.
The model accuracy based on traditional rapid molding technology has not been fundamentally breakthrough, which directly restricts its development, but also affects its market competitiveness and market share. In the early 1980s, China’s auto industry was at the initial stage of a major development. Due to the low starting point, small batch size and many varieties at the time, the traditional rapid molding technology was adapted to this situation, and was used in large quantities for small-batch production. Performance. According to incomplete statistics, there were hundreds of agricultural vehicle manufacturers in the 1980s using rapid tooling technology. This is enough to demonstrate the brilliance of rapid tooling technology. However, since the 1990s, with the establishment and development of the concept of economies of scale, the traditional rapid tooling has been shortened in life because of its short life and low precision. It has been placed in the steel mold from the withdrawal of the production field, and the rapid mold market has been gradually shrinking.  3. New Rapid Tooling Technology Continues to Occur
While the traditional rapid tooling technology has been severely challenged and the market has been severely shrinking, new rapid tooling tools have emerged. (1) Solid casting technology has been widely used in automobile mold manufacturing. (2) As a new type of elastic element, the nitrogen gas spring can effectively simplify the mold structure and realize the rapid manufacture of molds. It has been widely used in automotive molds. (3) Dieless multi-point forming technology breaks through the traditional concept of die forming, adopts a group of punches with adjustable height, replaces the traditional die for curved surface forming of panels, and uses CAD/CAM/CAT technology as the main technical means to rapidly realize Automatic shaping of three-dimensional surfaces. Dieless multi-point forming technology is another advanced rapid manufacturing technology that is different from the traditional rapid tooling technology. (4) Rotary casting forming technology, this technology is the use of heat-hardening silicone rubber to quickly make molds, using the rotary casting system to cast high-strength zinc aluminum alloy, aluminum-tin alloy and so on. This technology enables the rapid manufacture of certain specific parts. Second, the development trend of rapid mold making technology
The development of traditional rapid tooling technology has been challenged and the market has gradually shrunk. This is an indisputable fact. However, this did not hinder the rapid development of moldmaking technology, but it also stimulated people's desire to change this situation. The work around improving the accuracy of prototypes has not stopped. With the development of computer technology, numerical control technology, laser forming technology and material science, people are trying to use modern high technology to seek ways to improve the precision of prototypes. People use machinable plastics and use light copy milling to mill out the main model or process master model to make rapid tooling for the master model. Although this method improves the model accuracy, it has a longer processing cycle, higher cost, and a high degree of reliance on numerical control processing equipment, and the effect is not ideal in practical applications. At the end of the decade, the Rapid Prototyping Technology (RP) was first introduced in the United States. RP technology is accompanied by the development of computer technology, laser forming technology and new material technology. It is a brand-new manufacturing technology, based on novel discrete/stacked (ie, material accumulative) forming ideas, according to the CAD model of parts. Rapidly automate complex 3D solid (prototype) manufacturing. RP technology is a state-of-the-art high-tech technology for precision machinery manufacturing, computers, NC technology, laser forming technology, and materials science. It is comparable to the NC manufacturing technology that emerged in the 1960s and is considered to be the next step after NC technology. Technological revolution. 
The emergence of Rapid Prototyping Technology (RP) has created conditions for the rapid development of moldmaking technology. The introduction of RP technology can be said to be the best example of combining traditional rapid tooling technology with modern advanced manufacturing technology. RP technology has injected vitality into traditional rapid tooling technology. At the same time, traditional rapid tooling technology has provided technical assurance for the promotion and application of RP technology. 
In summary, the combination of rapid tooling technology and rapid prototyping technology will be the direction for the further development of traditional rapid tooling technology, and it is also a wide range of application fields where RP technology develops toward rapid tooling manufacturing. With the advancement of modern technology, traditional rapid tooling technology will inevitably gain new vitality, especially in the development of high-end technology products, will play a greater role.
Zhang Xunchun Sun Junqiang Song Baotong
Reprinted "Shanghai Mould Industry"  