3 D Is Printing Made To Replace Traditional Molds?

- Apr 25, 2019-

In recent years, with the development of industry 4.0, China's manufacturing industry has developed rapidly from "manufacturing" to "intellectual manufacturing", and 3D printing technology has been widely used in China's manufacturing industry. 3D printers can provide efficient and low-cost support for mold design and manufacturing. Even with the rapid development of 3D printing technology, in some areas, has gradually begun to subvert mold technology, forming a direct competition 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 introduces a new product, it must pass strict international standards and certification before it goes public, and the certification of many components will take a long time. This will put the new product in a very unfavorable position in the time to seize the market. The 3D printing injection mold is an efficient solution. This is done by well-known manufacturers who use 3D printing technology to manufacture injection molds in their open laboratory. According to Luobaihui, Secretary-General of the International Model Association, under normal circumstances, the production of a mold takes several weeks to two months, and the use of 3D printing technology can complete the mold prototype within a few hours, and can be based on the test results. Immediately modify. The final product sample of Zui is then molded. Samples of these products can be sent directly to certification. At this time, traditional mold manufacturing may still be in production. Even before the mold Zui is determined, the 3D printed product has passed certification, greatly shortening the development cycle. Only in the mold production cycle, 3D printing technology has produced a certain impact on the traditional mold manufacturing.
However, industry experts say that while 3D printing technology has many advantages such as short production cycle, convenient raw materials, and uniform product pressure, 3D printing technology can not completely replace traditional mold manufacturing methods. This is because 3D printing technology still has some problems in the manufacturing process. For example, 3D printing technology is processed layer by layer to obtain a product. Although this will shorten the mold's production cycle, it will also lead to a step pattern effect on the mold surface. There is a similar problem with directly printed molds, which later require machining or sandblasting to eliminate these small, dentate edges. In addition, holes smaller than 1 mm must be drilled. Larger holes need to be expanded or drilled. Thread features need to be threaded or milled. These secondary processes greatly weaken the speed advantage of 3D printing dies. At the same time, to ensure good material flow performance, injection mold needs to be heated to a very high temperature. Aluminum and steel molds usually experience a 500F(260 °C) or even higher temperature environment, especially when processing high-temperature plastics such as PEEK and PEI materials. It is easy to produce thousands of parts with metal molds, and can also be used as transition molds before the final production molds of Zui come out. Mold materials made 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 quickly damaged under the heat cycle conditions of injection molding. In fact, in mild environments, 3D printing molds usually fail within 100 times of use, 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 printing molds is their low cost. The manufacturing level machining die cost is generally $20,000 or more, which means that the same type of printing die is compared with the $1,000 printing die. However, this analogy is not fair. Chenben's assessment of the printing mold usually only considers material consumption, and does not consider manual, assembly and installation, injection systems and hardware. ProtoLabsd's aluminum molds, for example, cost $1,500 to produce. If you need to produce more parts, use 3D printing molds. For every 50-100 products produced, you need to reprint and assemble machines to test new molds. On the other hand, regardless of the plastic used, aluminum molds are usually still in service 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 been more than a century old. The industry has studied them thoroughly. For example, the angle of drawing die must be greater than or equal to 5 degrees to meet most aluminum mold requirements. The 3D printing mold injection plastic parts face challenges, and extra care is required on the number and installation location of the plastic mold thimble. 3D printing dies(especially high injection temperature) are somewhat more flexible in increasing the wall thickness of the cavity and reducing pressure. The design of the gate is also different, and the use of tunnel-type and point-like Gates should be avoided. Direct gate, fan gate, and wing gate should be increased to three times the normal size. The flow direction of the polymer in the printing mold should be consistent with the 3D print line to avoid high filling caused by viscosity 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 printing mold, because the heat dissipation of the 3D printing mold is not as good as that of aluminum mold or steel mold.
To sum up, 3D printing technology will not completely replace the status of traditional mold manufacturing. Because 3D printing die in the finished product quality, product cost and die design compared with the traditional mold manufacturing, there are certain deficiencies. Moreover, 3D printing is not suitable for mass production. The cost of producing 1 piece and producing 10,000 pieces is basically the same, and 3D printing takes a long time. The current 3D printing technology can only be used for the production of molds that require intense production during the small batch production cycle. The production of large quantities is still based on traditional molds.