DEFECT TOPIC
Gate clogging
Cured resin, carbon or foreign matter restricts flow. Check nozzle temperature, runner dead corners and purging sequence.
6 articles
Articles in this topic
View all articlesCauses of Nozzle Clogging: Premature Gate Freezing and Carbon Buildup
The previous shot was fine, but the next product has short shots or incomplete filling. Inspection reveals material frozen at a specific hot runner gate position, preventing material push-through. Most troublesome in multi-cavity molds—only one or two of dozens of nozzles clog, hard to detect without inspection, leading to defective batches before discovery.
Gate Defects in High-Temperature Molding: Why Machine Settings Only Offer Partial Relief
In LCP, PA6T, PA9T and PPS molding, stringing, drooling and nozzle clogging are common gate defects. Shops usually adjust temperature, injection speed and packing time, yet the improvement rarely holds. The cause is not only the parameters: a constant-temperature hot runner has to compromise across three stages of the molding cycle.
Stringing, Drooling and Clogging: Differences, Causes and Countermeasures
In high-temperature molding, stringing, drooling and clogging are often grouped together as gate defects, yet their symptoms, causes and adjustment directions differ. Without identifying the defect type first, a single parameter change may relieve one issue while worsening another.
Why LCP Gates Are So Prone to Defects
LCP is difficult to mold not because the machine is hard to set, but because the gate sits between high temperature and thermal degradation. High processing temperature, low melt viscosity, thermal sensitivity and the tight requirements of precision connectors combine to make stringing, drooling and clogging common. The article explains the four causes and how dynamic gate temperature control changes the timing.
Why Constant-Temperature Hot Runners Struggle with Stringing, Drooling and Clogging
Stringing, drooling and clogging look like machine-setting issues, but a constant-temperature gate stays molten through the whole cycle. The article explains how each defect forms, how FHFC freezes the gate before opening, and why lower temperature or shorter packing only treats symptoms.
Constant-Temperature vs FHFC Hot Runners: Principles Compared
Constant-temperature runners hold one high temperature for the whole cycle, while FHFC runners raise the gate before filling and drop it before sealing. The article compares control logic, working envelope, material fit and the order a selection decision should follow.
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