Common ink streaking phenomena in flexo printer slotter die cutters and effective ways to avoid them are as follows:
Common Ink Streaking Phenomena
1. Drum bearing wear: When the offset cylinder bearing is severely worn, sliding friction on the cylinder surface can cause ink streak marks to appear.
2. Hard lining and sliding phenomenon: When a hard lining is used, ink streaking can occur due to sliding during the printing process.
3. Gear wear: Severe wear of the roller gear increases the gear side clearance. After the rollers are engaged, gear vibration and sliding friction on the roller surface can lead to ink streaking.
4. Excessive pressure: If the pressure between the plate cylinder and the impression cylinder of the flexo printer slotter die cutter is too high, the blanket is squeezed, creating significant friction and sliding. This causes the longitudinal deformation of halftone dots to expand, resulting in ink streaks.
5. Gear contamination: Contaminants such as paper fibers and dried ink trapped between the gears can also cause ink streaking.
Effective Avoidance Methods
1. Replace worn bearings: Replace roller shafts or bearings that are severely worn to ensure the rollers operate normally.
2. Adjust the packing pad: Use soft pads to increase packing elasticity and reduce the likelihood of sliding.
3. Adjust the gears: Reduce the gear center distance or side clearance appropriately to ensure accurate gear meshing and minimize vibration and sliding.
4. Control printing pressure: Adjust the pad thickness according to equipment specifications to avoid excessive pressure and prevent ink streaks.
5. Strengthen cleaning and maintenance: Regularly clean and maintain the flexo printer slotter die cutter to keep gears, rollers, and other components free of contaminants that can affect print quality.
6. Adjust the ink: If the ink is too viscous, use additives to dilute it appropriately. Lower viscosity helps reduce friction and sliding during printing.
7. Choose the right paper: Select paper with high surface strength and good quality to avoid issues such as powdering, fiber pull-out, bubbling, and peeling. This improves overall printing quality.
