How to Solve Common Occurring Problems in Coating Machine Production?

In actual coating production, even with stable-running equipment, common issues affecting product quality are almost unavoidable. The capability of a coating machine to quickly and accurately troubleshoot and resolve these problems directly determines the effective uptime of the production line and the qualified-product rate. Drawing on practical experience, Nanjing Sumino Precision Machinery Co., Ltd. has summarized a systematic set of troubleshooting guidelines and solutions.

Coating Bubbles: Systematic Inspection from Slurry Feeding to Drying Bubbles in the coating layer rank among the most frequent defects during coating production. They may be caused by insufficient slurry defoaming, air entrainment inside feeding pipelines, or solvent bumping induced by excessive drying temperature. During troubleshooting, first check whether the slurry viscosity is too high and if sufficient defoaming time has been allowed. Next, inspect the feeding pipelines for air-leakage points. Finally, verify that the drying profile is gentle and temperatures of all sections are kept within a reasonable range. Coating machines manufactured by Nanjing Sumino Precision Machinery are equipped with an on-line defoaming unit and feeding-pressure monitoring system, which can effectively reduce bubble formation.

Uneven Thickness: Targeted Inspection from Material Feeding to the Coating Head Uneven coating thickness will trigger performance fluctuations of functional coatings. Root causes are generally located in two key sections: the feeding system and the coating head. For the feeding system, inspect the metering pump for wear and check pipelines for blockages or air leaks. For the coating head, confirm the uniformity of the die gap and check the lip surface for damage or accumulated contaminants. Our coating machines adopt an on-line thickness gauge paired with an automatic adjustment system, enabling real-time monitoring of thickness deviation and fine automatic correction.

Surface Defects and Substrate Breakage: Rapid Diagnosis Covering Environment and Tension Surface defects such as orange-peel texture and scratches usually stem from high drying temperature that forms a skin on the wet coating, dust or foreign debris on air nozzles, and contaminants adhered to the coating-head lip. Substrate breakage is commonly caused by over-high tension, foreign objects on roller surfaces or inherent defects of the base material. Troubleshooting steps include checking temperature settings of each zone, cleaning air nozzles and the coating head, and verifying tension parameters as well as roller surface conditions.

Regular Maintenance — the Fundamental Measure for Problem Prevention Nanjing Sumino Precision Machinery provides customers with detailed maintenance manuals and on-site training to help establish a preventive-maintenance system. It covers critical items including periodic cleaning of coating heads, calibration of tension sensors and oven-air-nozzle cleaning. Potential failures can be eliminated at an early stage to guarantee long-term, stable operation of the coating machine.