fromtohot runner systemThe use of injection molding has the advantages of saving resources, improving automation production efficiency, and also improving product quality. It has also expanded its injection molding range in areas such as multi-color co injection and stacked multi cavity injection molding. Many injection mold factories now use hot runner technology for over 80% of their molds, but some injection mold factories still use less than 10%. The main reason for this is that the advantages of the hot runner system have not been fully demonstrated.

When it comes to hot runner, we can collectively refer to it as an injection mold accessory or injection molding peripheral equipment. The standard for measuring the quality of a hot runner company's products for general customers is whether you buy the more expensive or cheaper one, or whether it is the best. The key depends on whether you find the right supplier who can provide comprehensive supporting services with the user unit. That is to say, whether such suppliers have industry experience and experience, whether they have a certain design and after-sales technical team, and whether they also have corresponding production scale, whether they can meet the technical requirements of the user unit and the potential for collaborative new product development, and whether they can promptly solve various problems that may arise during the use of hot runner. Because in terms of hot runner technology, hot runner suppliers are involved in mastering electronic and electrical technology, metal material characteristics and processing technology, injection mold design, plastic raw material characteristics, injection molding process, and other complementary comprehensive cooperation technologies.

I will explain the hot runner technology from three aspects: design, use, and manufacturing.

In designing the hot runner and selecting a solution, it is necessary to consider:

1. For example, the first mock examination multi cavity plastic products and one cavity plastic products multi-point glue injection, these should be based on 3D plastic products or existing product mold testing experience to do mold hot runner design.

2. If it is a product with the first mock examination and multiple cavities of the same size, the mold design generally makes the cavity symmetrical glue injection; If the products with different sizes of the first mock examination and multiple cavities or the flow distance to the glue inlet varies, the balanced glue injection can only be obtained by designing the size ratio of the runner and gate or controlling the sequence of each glue injection through the valve gate.

3. For products with one cavity, it is necessary to choose multiple points for gluing or if the product has appearance requirements, it is not allowed to have gate marks on the surface of the product, but it is necessary to set gluing points here. In this case, analysis must be conducted through software such as Moldflow. The appearance of the product also needs to consider whether to choose the gate from the side or the gate from the flip side for gluing.

4. For defects such as product shrinkage, water lines, deformation, and injection marks, the selection of gate size and gate style is also very important. It is also necessary to ensure a balanced mold temperature through water or oil circuit design.

5. For different types of plastic raw materials for injection molding, the selection and processing technology of hot nozzles and splitter plates will also change accordingly.

6. Due to the influence of mold temperature and operating environment temperature, the heat loss caused by heat conduction, convection, radiation, and how to perform insulation, the time required for the hot runner to be heated to the plastic molding temperature, whether it is locally overheated, and whether the heat transfer is balanced are all factors that need to be considered in the design of the hot runner.

7. In addition to meeting the requirements of injection molded products, the design of hot runner also needs to consider whether the hot runner accessories are easy to process and whether they can be standardized, whether the accessory design can reduce the manufacturing cost of the hot runner, and whether it can reduce the usage cost of the user unit.

8. The design plan for the hot runner is achieved through two-way communication between the hot runner company and the user. Any changes made after the confirmation of the plan by both parties may result in time and cost losses for both parties.

Mastering the key points in using a hot runner is the key to making good use of the hot runner.

1. The hot nozzle and splitter plate are part of the mold structure, and their processing accuracy and fitting accuracy in the mold are issues. If both parties do not process according to the plan drawings, it will cause improper installation or leakage of the hot runner after use.

2. For the heating and temperature sensing circuits of the hot runner, there should be a clear location during installation; The connection method of the circuit should be in accordance with the requirements of the design plan or the wiring identification of the temperature controller, in order to facilitate disassembly and maintenance.

3. Insoluble impurities cannot be mixed in plastic raw materials, and the accumulation of small impurities can also block smaller flow channels and adhesive outlets.

4If the injection molding is made of fireproof or high gloss transparent raw materials, the plastic heating residence time in the hot runner should not be too long, otherwise it will cause the plastic raw materials to overheat and decompose, and the product will cause yellowing and black spots.

5. For injection molding of plastic raw materials containing fiber and carbon, temperature control should be precise. After shutdown, it is best to clean the material barrel and flow channel with raw materials that do not contain fiber or carbon. Otherwise, the next time the injection molding is started, there will be burnt and carbonized materials blocking the flow channel and gate.

6. Based on the specific problems that occur during use, the supplier and user unit will jointly analyze the reasons to avoid judgment errors and unnecessary losses

In terms of manufacturing hot runners, due to their customization and more non-standard production, the qualification rate of the manufactured hot runner must reach100%. So the manufacturing conditions for the equipment need to consider:

1. It is necessary to have precision processing equipment and precision testing instruments.

2. There should be skilled processing technicians and management personnel.

3. The drawing dimensions and production process are clear and complete.

4The materials used, the processing accuracy of all accessories, and the processing details should not be careless, otherwise abnormal problems may occur during the use of the hot runner.

Due to the late start of China's plastic injection molding industry, when it comes to hot runner manufacturing in China, what worries me the most is that in 2000, my boss (a foreigner) and I visited a large domestic port enterprise. The other party received us as an engineering manager. When they first introduced our company's products, the engineering manager asked, 'Which country's brand are you representing?' My boss answered in non-standard Mandarin - Chinese. The other party was surprised, and my boss added that foreign technology, made in China, is the same as foreign countries. The other party said that currently there are only foreign brands on the market, and they have not heard that China can do well. My boss is very angry, and he has a bad temper and says to the other party, 'What university did you attend?'? Isn't it the same between China and foreign countries? This incident dealt a deep blow to me: even foreigners have a sense of national integrity, let alone our lack of national dignity. Indeed, it was in China at that timeHot runnerManufacturing is a blank space. To buy a hot runner accessory, you have to find an agent to import it from abroad, and sometimes you have to wait for 20 to 40 days. Of course, the price is also exorbitant. It may cost over 20 yuan per screw, let alone a set of hot runner systems ranging from 20000 to millions. From this moment on, I have to study this technology well and also want to know how to make the hot runner system MADE IN CHINA.

In the 18th century, Britain was the benchmark of world technology and a leader in manufacturing. At that time, Germany's industrial production capacity and technological innovation capacity were half a century lower than those of Britain. And at the beginning, German manufacturing was also a copycat. Why can manufacturing companies survive in the cracks? Through imitation and innovation, after more than a century of development, coupled with the government's continuous improvement of regulatory mechanisms and methods, German manufacturing has already gained a global reputation.

Nowadays, there are more than 200 small and medium-sized hot runner manufacturing companies in the coastal areas of China. Some companies have gone through more than ten years of hard work, some can only manufacture a certain hot runner component, and some companies can also achieve small and precise in a certain plastic field. Like the development of China's reform and opening up, the entire hot runner manufacturing industry in China lacked comprehensive theoretical research in its early development. At that time, there was never any technical information on hot runners available for inquiry in the mechanical mold major of Chinese universities or domestic bookstores. We can only rely on some technical information from abroad, especially from Germany, the United States, Japan, etc. We have studied materials, processes, and structures, and have mastered some design theories and manufacturing processes. By combining with practice, seek truth in practice. Of course, in the early years, some hot runner manufacturing companies were small and developed all over the country, because there were many types of plastics, achieving a comprehensive approach posed great challenges. Because customers cannot be so professional about hot runners, if they use their products for testing, without experience from both parties, it may cause significant losses to customers, and even customers who have not used them well may no longer believe in Chinese made hot runners. However, after 2008, Chinese hot runner manufacturing companies were no longer small and comprehensive in development. They focused more on segmented fields and details, constantly innovating on the basis of previous experience, and achieving small and specialized, small and strong. In addition to the increase in domestic labor and plastic raw materials, China's manufacturing hot runner has been widely used in fields such as electronic appliances, office equipment, plastic packaging, daily necessities, and transportation. In terms of high-precision molds and large-scale molds, in addition to having cost-effectiveness advantages, it is important to fully compete with world brands. Including now, a considerable portion of our Chinese made hot runner has been sold directly or through matching Chinese made molds to developed and developing countries. In short, we hope to be like Made in Germany, with the belief of "manufacturing is strong, China is strong, and management changes China". Through patient innovation, research and development, lean management, and good government mechanisms, we will comprehensively upgrade China's hot runner manufacturing, making it a shining star in Chinese brand manufacturing, and allowing Made in China to gain more dignity in the world.

Note: Mr. Zhang from Haochen Hot Runner Company is participatingSpeech at the Third China Injection Molding Industry Conference 2015.