The mold is known as the 'mother of industry', and its application can be traced back to ancient times. In the past few decades, with the rolling of the wheel of the technological revolution, the mold manufacturing industry has opened a new chapter, and the technology has advanced by leaps and bounds. , has made a huge contribution to the processing industry. Nowadays, although the traditional manufacturing industry around the world still uses mold as the main production force, the development of the mold has been impacted by 3D printing technology.
In recent years, with the development of Industry 4.0, China's manufacturing industry has developed more rapidly from 'manufacturing' to 'intellectual manufacturing'. 3D printing technology has been widely used in China's manufacturing industry. 3D printers can be used as molds. Design and manufacturing provide efficient, 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.
It is understood that compared to 3D printing technology, traditional mold manufacturing requires more steps and processes, and the mold production cycle is longer. When a mold manufacturer introduces a new product, before the market, the new product needs to pass strict international standards and Certification, and the certification of many components will take a long time. This will put the new products in a very disadvantageous position in the market time. The 3D printing injection mold is an efficient solution. Well-known manufacturer Schneider Electric is doing this. In their open laboratory, using 3D printing technology to manufacture injection molds.
According to Schneider related personnel, it usually takes several weeks to two months to produce a mold, and the mold prototype can be completed in a few hours using 3D printing technology, and can be modified immediately according to the test results. Then injection molding The final product samples. These product samples can be sent directly for certification, while traditional mold manufacturing may still be in production, even before the final determination of the mold, 3D printed products have been certified, greatly shortening the development cycle.
Only in the mold production cycle, 3D printing technology has had a certain impact on the traditional mold manufacturing. However, industry experts said that although 3D printing technology has many advantages such as short production cycle, convenient raw materials, uniform product pressure, etc., 3D printing technology It does not completely replace the traditional mold manufacturing method, because 3D printing technology still has some problems in the manufacturing process.
For example, 3D printing technology is a layer-by-layer process to obtain a product, which will shorten the production cycle of the mold, but it will also lead to a stepping effect on the surface of the mold. Direct printing of the mold also has similar problems, and later requires machining or sandblasting. Eliminate these small, toothed edges. In addition, holes smaller than 1mm must be drilled, larger holes require reaming or drilling, and thread features require tapping or milling. These secondary treatments greatly weaken 3D. The speed advantage of printing molds.
At the same time, in order to ensure good material flow performance, injection molds need to be heated to very high temperatures. Aluminum and steel molds usually experience 500F (260 ° C) or higher temperature, especially when processing high temperature plastics, such as PEEK and PEI materials. It is easy to produce thousands of parts with metal molds. It can also be used as a transition mold before the final mass production mold. The mold materials made by 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, 3D printing molds usually fail within 100 times in mild environments, high temperature plastics such as polyethylene and or styrene. Filled with polycarbonate and high temperature resistant plastic, even producing only a few parts.
In addition, one of the main reasons for using 3D printing molds is their low cost. The production-level machining mold cost is generally $20,000 or more, which means that the same as the $1,000 printing mold is similar. But this analogy is not fair, print mold Chen Ben's assessment usually only considers material consumption, and does not consider labor, assembly and installation, injection systems and hardware. For example, ProtoLabsd's aluminum mold costs $1,500 for production. If you need to produce more parts, use 3D printing molds. Every 50-100 products are produced and reprinted. The assembly machine tests the new mold. On the other hand, regardless of the plastic used, the aluminum mold is usually still in good service after producing 10,000 parts. Therefore, in terms of production cost, 3D printing is no more cost effective than traditional mold making methods.
In addition, in the product design, the principle and practice of traditional injection mold manufacturing has more than a century of history, the industry is relatively thorough research, such as draft angle must be greater than or equal to 5 degrees, to meet most aluminum mold requirements. 3D Printing molds to mold plastic parts is a challenge, and the number and mounting position of the plastic mold thimbles require extra care. In terms of increasing the cavity wall thickness and reducing the pressure, 3D printing dies (especially high injection temperatures) are somewhat more Flexible. The design of the gate is also different. Tunnel and dot gates should be avoided. Direct gates, fan gates, wing gates should be increased to 3 times the normal size. The flow direction of the polymer in the print mold should be Consistent with 3D printing lines, avoiding high filling caused by stickiness and low pressure. The cooling system can improve the life of the mold to a certain extent, but it does not significantly reduce the number of cycles of the printing mold, because the heat dissipation capability of the 3D printing mold is not like the aluminum mold. Or steel mold is so good.
In summary, 3D printing technology will not completely replace the traditional mold manufacturing industry. Because 3D printing molds have certain shortcomings in terms of finished product quality, product cost and mold design compared with traditional mold manufacturing. Also, 3D printing It is also not suitable for mass production. The cost per unit of production and production of 10,000 pieces is basically close, and the time required for 3D printing is also longer. The current 3D printing technology can only produce tight mold production for small batch production cycles, large quantities. The production is still based on traditional mold manufacturing.