Calendering is a finishing process in which fabric is passed through a series of rollers under controlled temperature, pressure, and speed to achieve a smooth, glossy, or compressed surface. However, industrial calendering operations can sometimes encounter technical issues that affect product quality and machine performance. Below are some common heat transfer-related problems and their troubleshooting methods:
Symptom 1: Unstable temperature readings with wide fluctuations
Possible Cause: Incorrect piping connections, vapor lock, flow restrictions, or misrouted installation.
Solution: Verify all piping against original layout drawings. Ensure all high points are equipped with air vents and that pipes are correctly sized and routed.
Symptom 2: Pump operating but no/little flow
Possible Cause: Incorrect pump rotation or damaged impeller.
Solution: Confirm pump rotation matches manufacturer direction. Check impeller key and locknut—repair or replace if loose or broken.
Symptom 3: System fails to heat despite powered heaters
Possible Cause: Closed steam valve, blocked condensate line, or stuck cooling solenoid valve.
Solution: Ensure steam valve is open and condensate drains freely. Inspect solenoid valve; clean or replace if obstructed.
Symptom 4: Heating occurs without system demand
Possible Cause: Faulty steam solenoid valve.
Solution: Clean or replace the solenoid valve.
Symptom 5: Steam leakage or abnormal pressure spike when solenoid engages
Possible Cause: Failed steam trap or leaking heat exchanger tube.
Solution: Inspect and clean/replace steam trap. Check tube bundle in heat exchanger for leakage.
Symptom 6: Machine shuts down despite adequate water pressure
Possible Cause: Air trapped in line triggering safety switch.
Solution: Vent all air from roll loop lines. Install automatic air vents at all high points for continuous air removal.
Summary
Regular maintenance and systematic calibration are essential to minimize calendering defects and maximize production efficiency. Should issues persist, consult with our technical support team for machine-specific guidance or further assistance.
