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Surface structuring has attracted great attention due to the rising need of the industrial sector to improve their products through surface functionalization. A very promising technology for this purpose is Direct Laser Interference Patterning, which implements interference of multiple beams to directly form periodical patterns with a single laser pulse. This provides the ability to utilize the whole laser power for high speed structuring of large surface areas. However, in some cases even higher speeds are required. Therefore, alternative technologies like roll-to-roll hot embossing must be utilized. By the synergy of the DLIP technology, which is used for structuring the sleeves (embossing tool) and the roll-to-roll hot-embossing method, the throughput for the fabrication of micro/nano structured polymer foils can be increased at least one order of magnitude. Furthermore, since the sleeves are processed directly, without the need of lithographic methods, the fabrication cost of the textured sleeves can be significantly reduced (up to ~ 90%).
In this study, a unique DLIP-workstation is introduced, consisting of a ps-laser, several DLIP optics and a special positioning system for cylindrical parts. The system allows the patterning of cylindrical parts up to 600 mm in length and 300 mm in diameter. The structures, consisting of line-like or dot-like patterns with periods ranging from 5.5 µm down to 1.0 µm, can be produced with record processing speeds up to 5700 mm²/min. Finally, the implementation of these structured sleeves in a roll-to-roll system is demonstrated for imprinting polymer foils at an impressive surface throughputs of 12.5 m²/min, corresponding to web-speeds of 50 m/min. Additionally, some examples of the decorative elements processed by these technique are presented.
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