Flexographic printing uses a flexible printing plate to transfer ink through anilox rollers. It is a type of letterpress printing process, referred to as flexographic printing. The graphic part of the flexographic printing plate is raised. During printing, the anilox roller evenly coats a certain thickness of ink layer on the graphic part of the printing plate, and then transfers the ink layer of the graphic part under the pressure of the impression roller. to the surface of the substrate to form clear graphics and text. The inking mechanism of a flexographic printing press is usually a two-roller inking mechanism.
Meaning of Seamless Flexographic Sleeve
Seamless flexographic sleeves are usually made of high-strength polymer materials such as polyurethane. Its main characteristic is that there is no splicing gap of traditional printing plates and it presents a complete cylindrical structure. The outer surface is specially treated and can be used for pasting flexible printing plates; the dimensional accuracy of the inner surface is very high so as to be closely fitted and installed with the roller of the printing press.
Classification of Seamless Flexographic Sleeve
- Classified by material: Polyurethane sleeve; Rubber sleeve.
- Classified by thickness: Thin sleeve; Thick sleeve.
- Drilling Machines:
Ordinary printing sleeve (Various packaging printing, label printing, book and periodical printing, etc.)
Special printing sleeve (UV printing is used in high-end packaging. Anti-counterfeiting printing is used in fields such as bills and certificates.)
Materials Used in Manufacturing Flexograohic Seamless Sleeve
- Polyurethane(PU): Good elasticity, high strength, good wear resistance, high dimensional stability.
- Rubber: High elasticity, high flexibility, good shock absorption, corrosion resistance, low cost.
- Composites: Offer lightweight alternatives with high strength.
These materials are selected based on the specific demands of the sleeve application, ensuring optimal performance and longevity of the tool.
Application
Conclusion
Sleeves offer a significant reduction in the density of operators required and also mitigate the risk of equipment and printing plate damage during the loading and unloading process. Manufactured using specialized processes and materials, sleeves present lower manufacturing costs compared to traditional cylinder systems. Furthermore, their reusability cuts down on long-term operational expenses. Sleeves' compact design simplifies storage and reduces the need for ample space typically required for storing cylinders, aiding printing companies in conserving storage space and associated costs. The high processing accuracy of sleeves ensures excellent printing precision, with roundness, concentricity, and circumference errors tightly controlled within a narrow range, thereby minimizing printing quality issues due to equipment malfunctions.
Sleeves are particularly advantageous for printing high-quality, fine products, especially when paired with thin plates, allowing for the printing of fine highlight dots with minimal dot gain. This ensures the clarity of the printed pattern and the precision of color reproduction. The surface layer of the sleeves possesses excellent elasticity and compressibility, enabling adaptation to various printing surfaces and ensuring uniform distribution of printing pressure, which enhances printing quality and demonstrates good compatibility with a range of materials.
By employing sleeves of varying thicknesses, the required printing circumference can be adjusted. Only one size of air mandrel is necessary to accommodate a broad spectrum of printing circumference needs, facilitating personalized production. Sleeves also enable the printing of continuous lines, patterns, or uniform background colors, providing unique benefits for specialized printing tasks such as on packaging paper, cigarette paper, wallpaper, and more. Even when not imaged, sleeves can be utilized for coating, flood varnishing, and other applications.
