Registration inaccuracy in printing presses is mainly caused by four types of problems: mechanical wear, material characteristics, operational settings, and environmental factors.
1. Mechanical Component Issues
Wear on transmission parts such as gears and chains reduces drive precision over time, causing deviation in sheet or plate movement. Damaged bearings lead to unstable shaft rotation, which affects cylinder rotation accuracy and changes the relative position between the plate and the substrate.
2. Printing Material Issues
Paper characteristics play a major role. Changes in moisture content and dimensional stability can cause deformation. For example, paper that has not been conditioned in a high-humidity environment may absorb moisture and expand, disrupting registration accuracy. Plate quality also matters: surface contamination, scratches, or substandard dimensional accuracy on the printing plate can shift the ink transfer position.
3. Operational Setting Issues
Inconsistent pressure between cylinders can cause the sheet to shift or deform. For instance, excessive impression cylinder pressure may squeeze the paper and create registration deviation. Inaccurate adjustment of front lays and side lays prevents the sheet from reaching the correct printing position.
4. Environmental Factors
Changes in temperature and humidity affect both metal components and paper characteristics. Thermal expansion and contraction of metal parts, along with excessive temperature or humidity, can lead to registration errors.
For worn transmission components such as gears, bearing seats, and register guide rails, Hansheng Automation can provide custom machining of replacement parts from customer drawings or samples, helping restore stable registration performance.
