In daily production on Beiren (BEIREN) series printing presses, feeder paper-feed faults are among the most common issues encountered by press operators and maintenance personnel. As a representative domestic offset press, this model features strong parts interchangeability, low maintenance costs, and electrical systems mostly controlled by domestic PLCs. If not addressed promptly, the consequences range from compromised registration accuracy and print quality to prolonged downtime in severe cases.
1. Fault symptoms: During printing, frequent double sheets, missed sheets, skewed paper travel, or paper striking the front lays occur, leading to higher stoppage rates and unstable front-lay registration.
2. Cause analysis: Insufficient vacuum in the separating and forwarding suction nozzles, or blocked air lines and leaks; improper height adjustment of the pull lays and air-blast nozzles for sheet loosening, causing poor sheet separation; deviation in front/side lay adjustment on the feeder, or uneven pile surface; dirty or drifting sensitivity of the double-sheet detector (ultrasonic or mechanical type). Given the characteristics of Beiren domestic offset presses—strong parts interchangeability, low maintenance costs, and domestic PLC-based electrical systems—the troubleshooting sequence should prioritize key components and standard parameters.
3. Handling steps: Clean the air pump, air lines, and filters; measure and restore suction nozzle vacuum. Re-set the separating and forwarding suction nozzle heights and air volume according to paper grammage. Use a feeler gauge to correct the pull-lay height (approximately 3 sheets thick) and adjust the air-blast nozzle angle. Clean the double-sheet detector and recalibrate it; replace the sensing plate if necessary.
4. Preventive measures: Clean the feeder air-line filters and suction nozzles every shift. Regularly lubricate the feeder drive cams and bearings. Recalibrate feed parameters after changing paper grammage. The above methods also apply to models such as Beiren 300, Beiren 400, PZ4880, and N300. For practical operation, refer to the domestic CNC system / centralized lubrication control and on-site conditions. In complex cases, it is recommended to seek professional maintenance support via the printm.cn platform.
