Tsinghua hot runner technology is an advanced technology applied to the injection molding system of plastic injection molds. It is the hot direction of the development of plastic injection molding. The popularization in Europe and the United States can be traced back to the middle of the last century or even earlier. In China, the real application of this technology is only a matter of recent years.
The hot runner is heated to ensure that the runner and gate plastic stay molten. Since the heating rod and the heating coil are arranged near the flow path or in the center, the entire flow path from the nozzle outlet of the injection molding machine to the gate is in a high temperature state, so that the plastic in the flow path is kept molten, and it is generally not necessary to open the flow path to remove the coagulation after shutdown. Material, only need to heat the flow path to the required temperature when you turn on the power. Therefore, the hot runner process is sometimes referred to as a heat manifold system, or as a runnerless molding.
With the increasing application of hot runner technology, the proportion of hot runner molds in plastic molds will gradually increase. In foreign countries, more than 50% of molds produced by many plastic mold factories use hot runner technology, and some even reach over 80%, and the effect is very obvious. Hot runners have also been used for production in China, but the current total is less than 10%. This gap is quite large, but it also means that this industry has considerable room for development in China.
In recent years, the gradual promotion of hot runner technology in China has been largely due to the rapid export of domestic molds to European and American companies. In Europe and the United States, injection molding production has become quite dependent on hot runner technology. It can be said that molds that do not use hot runner technology are now difficult to export. However, due to the fact that many imported hot runner molds are expensive, a large number of domestic manufacturers cannot accept them, so some domestically produced hot runner molds have emerged. This has great benefits for the promotion of hot runner technology in China.
While hot runner technology is gradually becoming hotter in China, its components present several major development trends.
One is the miniaturization of components. With the miniaturization of components, small-sized products can be molded in multiple cavities and large-sized products can be filled in multiple gates. By reducing the nozzle space, more cavities can be configured on the mold to increase product yields and injection machine utilization, which is very important for the modern plastics processing industry where time is money. The nozzles developed by international well-known mold company MoldMaters for small parts include integral heaters, tips and melt channels. The volume diameter is less than 9mm, the gate distance is only 10mm, and the product can be formed with a mass of 1 to 30g.
The second is component standardization. At present, users require shorter and shorter mold design and manufacturing cycles, and standardization of hot runner components not only helps reduce duplication of design work and reduces mold cost, but also facilitates the replacement and maintenance of delicate parts. The nozzles, stems, and manifolds of Husky, Presto, and MoldMaters are standard models for quick replacement and delivery of molds. Now only four weeks abroad can deliver the mold.
The third is design reliability. Nowadays, major mold companies at home and abroad attach great importance to the design of hot runner plates and the pressure distribution, temperature distribution, and sealing of the hot nozzle joints. The development and use of laminated hot runner injection molds are also hot spots. The stack mold can effectively increase the number of cavities, and the injection molder force requirement only needs to increase by 10% to 15%. Stacked hot runner molds have been industrialized in some developed countries.
The fourth is the precise temperature control system. In the hot runner mold molding, the development of more precise temperature control devices to control the temperature of the molten resin in the hot runner plate and the gate is an effective measure to prevent the degradation of the resin and the degradation of the product performance.
It can be said that the wide application of hot runner technology is a major change in plastic molds. In injection molding, it has quite a few unparalleled advantages. As technology matures and manufacturing costs decrease, hot runner technology will increasingly show tremendous advantages. In recent years, the world-famous hot runner technology suppliers have successively entered the Chinese market in various ways. This shows that the Chinese hot runner mold market has great potential for development.
At the same time, this trend is also playing a huge role in promoting the rapid advancement of technology in the Chinese mold industry. A large number of emerging private enterprises in China have also recognized the unlimited business opportunities in this field and have established hot runner production companies one after another. This is of great significance for reducing the use of hot runner technology and accelerating its application. However, on the whole, most of the technologies that can be provided by local companies in China are still relatively elementary. The choice is small, the quality is unstable, and the maintenance period is short. This often affects the trust of downstream companies in their products. Therefore, the formulation of national standards for hot runner components, active production of inexpensive and high-quality components, and promotion of hot runner technology are the key to the development of domestic hot runner molds.
The hot runner is heated to ensure that the runner and gate plastic stay molten. Since the heating rod and the heating coil are arranged near the flow path or in the center, the entire flow path from the nozzle outlet of the injection molding machine to the gate is in a high temperature state, so that the plastic in the flow path is kept molten, and it is generally not necessary to open the flow path to remove the coagulation after shutdown. Material, only need to heat the flow path to the required temperature when you turn on the power. Therefore, the hot runner process is sometimes referred to as a heat manifold system, or as a runnerless molding.
With the increasing application of hot runner technology, the proportion of hot runner molds in plastic molds will gradually increase. In foreign countries, more than 50% of molds produced by many plastic mold factories use hot runner technology, and some even reach over 80%, and the effect is very obvious. Hot runners have also been used for production in China, but the current total is less than 10%. This gap is quite large, but it also means that this industry has considerable room for development in China.
In recent years, the gradual promotion of hot runner technology in China has been largely due to the rapid export of domestic molds to European and American companies. In Europe and the United States, injection molding production has become quite dependent on hot runner technology. It can be said that molds that do not use hot runner technology are now difficult to export. However, due to the fact that many imported hot runner molds are expensive, a large number of domestic manufacturers cannot accept them, so some domestically produced hot runner molds have emerged. This has great benefits for the promotion of hot runner technology in China.
While hot runner technology is gradually becoming hotter in China, its components present several major development trends.
One is the miniaturization of components. With the miniaturization of components, small-sized products can be molded in multiple cavities and large-sized products can be filled in multiple gates. By reducing the nozzle space, more cavities can be configured on the mold to increase product yields and injection machine utilization, which is very important for the modern plastics processing industry where time is money. The nozzles developed by international well-known mold company MoldMaters for small parts include integral heaters, tips and melt channels. The volume diameter is less than 9mm, the gate distance is only 10mm, and the product can be formed with a mass of 1 to 30g.
The second is component standardization. At present, users require shorter and shorter mold design and manufacturing cycles, and standardization of hot runner components not only helps reduce duplication of design work and reduces mold cost, but also facilitates the replacement and maintenance of delicate parts. The nozzles, stems, and manifolds of Husky, Presto, and MoldMaters are standard models for quick replacement and delivery of molds. Now only four weeks abroad can deliver the mold.
The third is design reliability. Nowadays, major mold companies at home and abroad attach great importance to the design of hot runner plates and the pressure distribution, temperature distribution, and sealing of the hot nozzle joints. The development and use of laminated hot runner injection molds are also hot spots. The stack mold can effectively increase the number of cavities, and the injection molder force requirement only needs to increase by 10% to 15%. Stacked hot runner molds have been industrialized in some developed countries.
The fourth is the precise temperature control system. In the hot runner mold molding, the development of more precise temperature control devices to control the temperature of the molten resin in the hot runner plate and the gate is an effective measure to prevent the degradation of the resin and the degradation of the product performance.
It can be said that the wide application of hot runner technology is a major change in plastic molds. In injection molding, it has quite a few unparalleled advantages. As technology matures and manufacturing costs decrease, hot runner technology will increasingly show tremendous advantages. In recent years, the world-famous hot runner technology suppliers have successively entered the Chinese market in various ways. This shows that the Chinese hot runner mold market has great potential for development.
At the same time, this trend is also playing a huge role in promoting the rapid advancement of technology in the Chinese mold industry. A large number of emerging private enterprises in China have also recognized the unlimited business opportunities in this field and have established hot runner production companies one after another. This is of great significance for reducing the use of hot runner technology and accelerating its application. However, on the whole, most of the technologies that can be provided by local companies in China are still relatively elementary. The choice is small, the quality is unstable, and the maintenance period is short. This often affects the trust of downstream companies in their products. Therefore, the formulation of national standards for hot runner components, active production of inexpensive and high-quality components, and promotion of hot runner technology are the key to the development of domestic hot runner molds.