The Importance of Hot Runner to Precision Mold Manufacturing

Hot runners have become indispensable in injection molding production. For precision mold manufacturing factory, choosing a hot runner suitable for product molding and mastering the correct use of the hot runner are the keys to benefiting from the hot runner.

The Importance of Hot Runner to Precision Mold Manufacturing

Hot runner (HRS) turns the solidified sprue into a molten sprue. Its composition is relatively simple, mainly including manifold, hot nozzle, temperature controller, etc. Among them, the manifold can be divided into I-shaped, X-shaped, Y-shaped, T-shaped, mouth-shaped and other special shapes; the hot nozzle can be divided into large nozzle, sharp nozzle, needle valve nozzle according to its shape; the temperature controller can be divided into core type, card type and computer centralized control type according to the temperature control method.

In injection molding, hot runners are used in conjunction with molds and play a very important role. For example, in the injection molding of ultra-thin parts (such as mobile phone battery covers), high-precision, high-quality products can be easily produced by using hot runners; for injection molding materials with poor fluidity (such as LCP), the use of hot runners can significantly improve the fluidity of the materials and ensure smooth injection molding; for some large injection molding parts, such as automobile bumpers and door panels, TV rear shells, air conditioner shells, etc., the use of hot runners makes very difficult injection molding relatively simple.

In multi-cavity mold injection molding, molding is impossible without hot runner. It can be said that hot runner is the best technology to ensure runner balance. Because plastic has shear force in the runner, no matter how reasonable the geometric balance of the mold is, the weight of the molded product is difficult to be consistent. Especially for multi-cavity molds, if hot runner is not used, the outside of the molded product will be lighter than the inside.

For plastic injection molding manufacturers, quality of precision mold manufacturing depends on if they use hot runner, as long as there is a certain batch of injection molding production, the use of hot runners is quite economical. This is because hot runners help companies eliminate sprues in injection molding production.

In most cases, sprues cannot be reused. Sometimes, the weight of the sprue is almost the same as the weight of the product. If the traditional sprue injection molding method is used, it means that the waste of raw materials is the same as the raw materials used in the product. Based on this calculation, after using hot runners, 30% to 50% of raw materials can be saved. In addition, hot runners also help reduce mold wear and extend the life of the mold. In general, the service life of hot runner molds is twice that of pin point gate molds.

Things to note when installing hot runners in injection molds

1. Fully inspect the hot runner, including all dimensions, resistance, and quantity;

2. Fully inspect the dimensions of the mold and hot runner-related parts;

3. Before installing the panel, the hot runner must be carefully inspected with a temperature controller. Only after confirming that it is working properly can it be operated on the machine;

4. Before production, the hot runner must be finally inspected with a multimeter, otherwise it is not allowed to start the machine;

5. Before closing the mold, it must be empty shot. During the empty shot, cover the B plate mold with cardboard, and then close the mold for trial.

In order to help injection mold factories use hot runners correctly, hot runner suppliers should train customers. The training content should include:

6. The basic principle of hot runners. The hot runner keeps the plastic in the runner in a molten state by electric heating. Here, it is necessary to emphasize to customers that when the hot runner works in the mold, it needs to have good insulation measures. For this reason, square iron cannot be used as a substitute when making the manifold cavity. This is very important in injection molding.

7. Learn to install and disassemble the hot runner correctly. First of all, the injection molding factory must be very familiar with the sealing position of the hot runner, which includes the sealing of the hot nozzle and the manifold, the sealing of the hot nozzle and the mold A plate, the sealing of the main nozzle and the panel, the sealing of the valve needle and the valve needle guide sleeve, and the sealing of the main nozzle and the hot runner plate.

8. Maintenance and care of the hot runner. The injection molding factory must know that once the hot runner has a problem, it must be removed from the mold for repair, and this process takes at least 8 hours. For the injection molding factory, the loss cost is about 10 times that of the hot runner supplier. Therefore, it is very important to have a dedicated full-time or part-time person to maintain the hot runner.

Yuanfang provide custom injection mold making service with best quality in China, to worldwild plastic injection molding manufacturer.