In the daily production of Ryobi (Ryobi / Liyoubi) series presses, dot gain distortion is one of the most common problems encountered by press operators and maintenance personnel. This model is a mainstay in the Japanese small-to-medium format segment, featuring simple operation, a straightforward air and dampening system, and easy maintenance. If not addressed promptly, it can range from affecting registration accuracy and print quality to causing extended downtime.
1. Fault Symptoms: Shadow areas become blocked, highlight areas become blocked, dot gain exceeds the standard, tonal gradation is lost, and prints show color deviation.
2. Cause Analysis: Excessive printing pressure, overly thick packing, inappropriate blanket hardness, excessive ink flow, and lack of dot gain compensation (G7/dot curve) calibration. Given the Ryobi's characteristics as a Japanese small-to-medium format workhorse with simple operation, straightforward air and dampening circuits, and easy maintenance, troubleshooting should prioritize checking key components and standard parameters.
3. Practical Repair: Reduce printing pressure to standard levels, reduce packing thickness, replace blankets with appropriate hardness, adjust ink viscosity and flow, and introduce dot gain compensation curves.
4. Preventive Measures: Regularly plot print characteristic curves, keep pressure within standard ranges, and calibrate color management.
The above methods also apply to models such as the 920, 1050, 920PF, and MHI. For actual implementation, refer to the PCS console / automatic dampening system and on-site conditions. In complex cases, it is recommended to seek professional maintenance assistance through the printm.cn platform.
