Guidelines for Using and Maintaining Flexographic Sleeves

 

    Usage Guidelines for Flexographic Sleeves: Before using a flexographic sleeve, ensure that the surface's anti-rust oil is wiped clean and inspect for any dents, scratches, or other issues. Factory-treated flexographic sleeves should not be further sanded with coarse sandpaper unless necessary. If sanding is required, use fine-grit sandpaper. Avoid any sharp or pointed objects coming into contact with the surface when mounting or printing to prevent damage. Use dedicated scraper blades for printing and inspect them for damage before each use. Damaged blades should be repaired or replaced, and blade edges should be polished before printing. Adjust the angle and pressure of the scraper blade according to the specific printing pattern. Filter ink before printing to prevent potential damage to the surface caused by particles in the ink.

    Maintenance Guidelines for Flexographic Sleeves: After printing, clean ink residue from the sleeve's surface and cells. Use a cleaning agent to remove ink residue from the cells to prevent blockages. Avoid touching or handling flexographic sleeves with bare hands before and after use to prevent oxidation. If contact occurs, immediately clean the surface with a solvent. In humid conditions, avoid storing flexographic sleeves in enclosed containers, especially during summer. Before storage, clean the surface and apply a generous layer of anti-rust oil. Wrap the sleeve in clean plastic wrap or paper, ensuring the entire sleeve, including the surface and ends, is covered to prevent air exposure. Store in a well-ventilated and dry environment, away from corrosive substances. Common Printing Issues and Their Solutions: Various factors affect the quality of gravure printing, including workshop environment, impression roller pressure, scraper blade pressure and angle, printing speed, ink viscosity, tension control, drying system, and flexographic sleeve quality. Maintaining strict control over these factors is essential to ensure high-quality gravure printing results.

1. Workshop Temperature and Humidity: Excessively high or low temperatures and humidity in the workshop can lead to issues such as ink tackiness, color shifting, adhesion problems, and ink degradation. Maintaining a temperature of 20-25°C and relative humidity of 55%-75% is recommended.
2. Impression Roller Pressure: Select a well-balanced, high-quality impression roller with appropriate surface characteristics. Adjust pressure based on printing method (surface printing, reverse printing), substrate material (paper, aluminum foil, plastic), and thickness.
3. Scraper Blade Pressure and Angle: Maintain a scraper blade angle of 45-65° and adjust as needed based on image depth and printing speed. Ensure proper distance between the scraper blade and impression roller, applying suitable pressure to prevent damage to the surface.
4. Printing Speed: Avoid exceeding the maximum printing speed of the machine. Select the appropriate printing speed based on printing method, workshop environment, substrate, and design, ensuring optimal print quality.
5. Ink Viscosity: Adjust ink viscosity based on printing speed. Faster printing requires fast-drying solvent-based inks, while slower printing benefits from slow-drying solvent-based inks. Add solvent to the ink mixture during printing to maintain consistent ink properties and color.
6. Drying System: Properly matched drying systems improve ink adhesion and prevent tackiness, odor, and other issues. Adjust oven temperature and airflow based on image size and printing speed.
7. Flexographic Sleeve Quality: Flexographic sleeve quality significantly impacts print quality. Factors such as precision, balance, chrome hardness, and surface polishing affect registration, ink drying, and overall performance. Addressing these factors ensures consistent, high-quality gravure printing results."

 

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