Gravure roll systems are a fundamental coating process popularized in the printing industry. A relief pattern etched into a roller defines a volume for material transport. A roller partially submerged in ink rotates in and out of the fluid. It is squeegeed by a “doctor blade” to remove the excess fluid. which was protruding above the surface. In printing, the material left in the relief pattern is then transported to an intermediary roller and then to a moving material – typically paper or cardboard replicating the pattern.
When a more precise uniform continuous nonpatterned coating is desired, the roll is best set-up spinning in the opposite direction of the web. This is referred to as the reverse kiss method. It basically homogenizes the pattern while transferring the material. Typically, a triangular or trihelical groove pattern is etched into the gravure roll at an angle of about 45 degrees. A high groove density 100-300 Line Per Inch (LPI) shallow depth pattern is used for thin coating while a low groove density 30-80 for depositing thicker coatings. The material transferred is proportional first to the void reservoir in the pattern and secondarily to the ratio of gravure speed to line speed
Small diameter coating rolls have the advantage of providing better uniformity for coating than gravures with traditionally larger diameter rolls and thus its applicability to precision applications.
Features and Benefits
- Suitable for transferring photoresist for Optical Lithography and NIL
- Coats as thin as 0.05 micron (with solvent) and as thick as 100 micron
- Ability to coat web at speeds of 5-800in/min on thin substrates
- Moderate material viscosity range
- Compact, Mountable to Carpe Diem Modules, Easily Adjustable
- Small diameter roll produces stable wetting bead for superior coating uniformity
- Compatible with Yasuii Seiki Microgravure™ rolls
|Accuracy of Coating Thickness||2-5%|