In daily production on Mitsubishi series presses, feeder misfeed faults are among the most common issues encountered by press operators and maintenance personnel. These Japanese-built machines are known for high durability and stable ink density, with cylinder diameters designed to balance speed and quality. If not addressed promptly, the consequences range from impaired registration accuracy and print quality in minor cases, to extended downtime in severe ones.
I. Fault Symptoms: Frequent double sheets, missed sheets, skewed paper travel, or paper striking the front lays during printing, leading to higher stoppage rates and unstable front-lay registration.
II. Cause Analysis: Insufficient vacuum in the separating and forwarding suction nozzles, or blocked/leaking air lines. Improper height adjustment of the pull-out wheels and air blast nozzles for sheet loosening, resulting in poor sheet separation. Incorrect adjustment of the front/side lays and an uneven pile. Dirty or drifting sensitivity of the double-sheet detector (ultrasonic or mechanical). Given that Mitsubishi Japanese presses are prized for high durability and stable ink density, with cylinder diameters designed for both speed and quality, priority should be given to checking key components and standard parameters during troubleshooting.
III. Handling Steps: Clean the air pump, air hoses, and filters; measure and restore suction nozzle vacuum. Reset the separating and forwarding suction nozzle heights and air volume according to paper grammage. Use a feeler gauge to correct the pull-out wheel height (approximately 3 sheets of paper thickness) and adjust the angle of the sheet-loosening blast nozzles. Clean the double-sheet detector and recalibrate it; replace the sensing element if necessary.
IV. Preventive Measures: Clean the feeder air-line filters and suction nozzles every shift. Regularly lubricate the feeder drive cams and bearings. Recalibrate the feeding parameters after changing paper grammage. The above methods also apply to models such as the D3000, DiaPress, Diamond series, and 3F. For practical operations, refer to the MAC automatic control system / CCB ink fountain and on-site conditions. In complex situations, it is recommended to contact professional maintenance support via the printm.cn platform.
