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Chengdu Hot Runner Analyzes the Reasons for Leakage of Hot Runners for Customers of Plastic Mold Hot Runners
Chengdu Hot Runner Analyzes the Causes of Hot Runner Leaks for Plastic Molding Customers
By Text / Thermal Hot Runner
The issue of hot runner system leaks has always been a major concern for most injection molders. Many worry that their hot runners might leak, which could lead to significant problems. So how can hot runner suppliers prevent such leaks? Today, we’ll discuss the reasons behind these leaks with Mr. Zhu Guodong, a senior engineer at Chengdu Hot Runner Thermal Constant Flow Runner. With over a decade of experience in the hot runner industry, Mr. Zhu has tackled issues related to tens of thousands of hot runners during after-sales services, gaining extensive practical expertise in resolving hot runner problems.
A hot runner system leak can severely impact a customer's production schedule. In extreme cases, it can even damage the heat ring or other critical system components. There are numerous reasons why hot runner systems may leak, but regardless of the specific cause, the first step is always to analyze the situation before developing an appropriate maintenance plan. Here, we analyze the potential causes of hot runner leaks:
1. The support pad is too low. Under injection pressure, the runner plate and the hot nozzle separate, creating a gap that results in glue leakage.
2. The support pad is too high. The support block enters the front mold baseplate, preventing glue from leaking between the flow plate and the hot nozzle. However, under injection and clamping pressures, the flow channel plate shifts sideways, causing glue leakage.
3. The center pad is too high. The runner plate is unsupported on the center pad, leading to separation between the runner plate and the hot nozzle, which creates a gap and results in glue leakage.
4. The center pad is too low. During injection molding, the center pad collapses under pressure, causing glue leakage.
5. The nozzle tip height is uneven. A low hot nozzle tip is prone to leakage.
6. The distance between the fixing screws and the flow plate or nozzle is too large. This results in insufficient sealing between the runner plate and the hot nozzle, leading to glue leakage.
7. The positioning pin is too high. The flow channel plate is unsupported on the positioning pin, causing it to separate from the hot nozzle and create a gap, resulting in glue leakage.
8. The hot nozzle is too long. Without room for expansion, it generates excessive pressure, compromising the sealing ring’s functionality and causing glue leakage.
9. The seal is either too high or too low. The sealing ring requires approximately 0.3 mm of pre-compression on the hot nozzle's surface. If the seal is too high, it can deform the flow channel plate, making it prone to leakage. If it's too low, there's insufficient initial pressure, and the hot runner system will leak once heated.
10. The hot nozzle positioning is incorrect. If the hot nozzle head is positioned on the front mold or the front mold insert rather than directly on the front mold, the injection pressure or clamping pressure can force the hot nozzle against the front mold core, causing glue leakage.
In conclusion, understanding these common causes of hot runner leaks is crucial for maintaining efficient operations and minimizing downtime. Addressing these issues promptly not only ensures smooth production but also extends the lifespan of your hot runner system. Proper installation, regular maintenance, and using high-quality components are essential steps toward preventing leaks and ensuring optimal performance.