How to Determine if Hot Runner Repair is Needed Again

We know from our previous experience in the repair and maintenance of hot runner thermal shock cracks that we can judge whether the hot runner has to be repaired again through multi-dimensional abnormal signals:

I. Visual and Flaw Detection Signals

Visual Inspection: Presence of new visible linear microcracks in the weld repair region or the adjacent stress concentration locations.

Flaw detection: In routine penetrant testing, the discovery of new microcracks that are not present before is an indicator of stress starting to release and cracking.

II. Indications of Production Condition

Abnormal Glue Leakage: There is an unexplained localized glue leakage in injection molding. This can be verified when the aging of seals has been excluded.

Abnormal Temperature The hot runner zone is heated normally, but the local temperature is always lower than the prescribed value, indicating that the heat conduction structure has been cracked.

III. Performance Parameter Signals

Injection Fluctuation : Unsteady Oscillation of Injection Pressure Causes Instability Defects such as Flash and Insufficient Glue in the Product. This can be proven once the raw material and the injection molding machine factors have been eliminated.

Geometric deviation: Slight deformation of the reference surface of hot runner mounting does not permit full fitment after bolt tightening, leading to sealing failure.

Any of these indications indicates new damage to the hot runner which has to be repaired immediately to avoid further damage and possible mass production accidents.