In recent years, with the development of Industry 4.0, China's manufacturing industry has developed faster and faster from "manufacturing" to "intelligent manufacturing". 3D printing technology has been widely used in China's manufacturing industry. 3D printers can be used as molds Design and manufacture provide efficient and low-cost support. Even with the rapid development of 3D printing technology, in some areas, it has gradually begun to subvert the mold technology and form a direct competitive relationship with it.
"Compared to 3D printing technology, traditional mold manufacturing requires more steps and processes, and the mold production cycle is longer. When a mold manufacturer launches a new product, the new product needs to pass strict international standards and certification before it is launched. The certification of many parts will take a lot of time. This will put new products in a very disadvantageous position in terms of time to seize the market. 3D printed injection molds are an efficient solution. Well-known manufacturers Yimiao do this In their open laboratory, they use 3D printing technology to manufacture injection molds." According to Luo Baihui, Secretary General of the International Mold Association, it usually takes a few weeks to two months to produce a mold, while using 3D printing technology The prototype of the mold can be completed within a few hours, and can be modified immediately according to the test results. Then injection molded the final product sample. These product samples can be sent directly for certification, and at this time the traditional mold manufacturing may still be in production. Even before the mold is determined, the 3D printed finished product has been certified, greatly reducing the development cycle. Only in the mold production cycle, 3D printing technology has had a certain impact on traditional mold manufacturing.
However, industry experts said that although 3D printing technology has many advantages such as short production cycle, convenient raw materials and uniform product pressure, 3D printing technology cannot completely replace the traditional mold manufacturing method. This is because 3D printing technology also has There are some problems. For example, 3D printing technology produces products layer by layer. Although this will shorten the production cycle of the mold, it will also cause a step effect on the surface of the mold. Directly printed molds have similar problems. Later, machining or sandblasting is required to eliminate these small, toothed edges. In addition, holes smaller than 1mm must be drilled, larger holes need to be reamed or drilled, and thread features need to be tapped or milled. These secondary treatments greatly weaken the speed advantage of 3D printing molds.
At the same time, in order to ensure good material flow properties, the injection mold needs to be heated to a very high temperature. Aluminum molds and steel molds usually experience 500F (260°C) or higher temperature environment, especially when processing high-temperature plastics, such as PEEK and PEI materials. It is easy to produce thousands of parts with a metal mold, and it can also be used as a transition mold before the final mass production mold comes out. The mold materials manufactured using 3D printing technology are generally photosensitive or thermosetting resins, which are cured by ultraviolet light or laser. Although these plastic molds are relatively hard, they are destroyed very quickly under the thermal cycling conditions of injection molding. In fact, in mild environments, 3D printed molds often fail within 100 uses, high-temperature plastics such as polyethylene and styrene. For glass-filled polycarbonate and high-temperature plastics, only a few parts can be produced.
In addition, a major reason for using 3D printed molds is their low cost. The cost of production-level machined molds is generally $20,000 or more, which means that it is comparable to $1,000 printed molds. However, this analogy is not fair. The evaluation of printed molds usually only considers material consumption, and does not consider labor, assembly and installation, injection systems and hardware. For example, ProtoLabsd's aluminum molds can be used for production for $1,500. If you need to produce more parts, use 3D printing molds. Every 50-100 products need to be reprinted and the assembly machine tests new molds. On the other hand, irrespective of the plastic used, aluminum molds usually still serve well after producing 10,000 parts. Therefore, in terms of production costs, 3D printing is not more cost-effective than traditional mold manufacturing methods.
In addition, in product design, the principles and practices of traditional injection mold manufacturing have more than a century of history, and the industry has studied it thoroughly. For example, the draft angle must be greater than or equal to 5 degrees to meet most aluminum mold requirements. 3D printing molds face injection molding plastic parts, but they face challenges. The number and installation positions of plastic mold thimble need extra care. In terms of increasing cavity wall thickness and reducing pressure, 3D printing molds (especially high injection temperatures) are somewhat more flexible. The design of the gate is also different, and tunnel and point gates should be avoided. Direct gate, fan gate, wing gate should be increased to 3 times the normal size. The flow direction of the polymer in the printing mold should be consistent with the 3D printing line to avoid high filling caused by stickiness and low pressure. The cooling system can increase the life of the mold to a certain extent, but it will not significantly reduce the number of cycles of the printed mold, because the heat dissipation capacity of the 3D printed mold is not as good as the aluminum or steel mold.
In summary, 3D printing technology will not completely replace the status of traditional mold manufacturing. Compared with traditional mold manufacturing, 3D printing molds still have certain deficiencies in the quality of finished products, product cost and mold design. Moreover, 3D printing is not suitable for mass production. The cost unit price of producing 1 piece and 10,000 pieces is basically close, and the time required for 3D printing is also longer. The current 3D printing technology can only be used for the production of molds with tight production cycle requirements, and large-scale production is still dominated by traditional mold manufacturing.
