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MICROGRAVURE™

microgravure 1

What is MICROGRAVURE™?

A smaller diameter gravure roll engraved with patterns or cells to provide a specific coating volume. It is used in a reverse kiss coating method in which the roll is partially submerged in a pan of solution. The roll rotates in the opposite direction of the web, and the cells pick up the coating solution. The flexible doctor blade lightly smoothes off the excess and the precisely measured solution in the cells is then transferred to the web.

MICROGRAVURE™ Catalog

microgravure rolls

What Can MICROGRAVURE™ Do?

  • Offers exceptional uniformity: ±1-2% tolerance
  • Coats 0.5 to 80 microns wet, as thin as 5 nanometers dry
  • Coats low viscosity solutions (0-1000 cP), both aqueous and solvent based
  • Coats on thin substrates such as PET, PC, PP, aluminum, copper, stainless steel, paper and fabric
    • PET: as thin as 3um
    • Aluminum foil: as thin as 6um
    • PC: as thick as 750um
  • Suitable for evenly coating suspensions with rigid particles

Why Is MICROGRAVURE™ Better Than Regular Gravure?

  • The smaller diameter provides a much smaller contact area (a), which allows for an exceptionally stable bead of solution that is critical for thin, uniform and glossy coatings
  • The larger web-to-roller distance (b) minimizes streaks and offers cleaner lines
  • No backing roll – means no creasing, smaller contact area, prevents spillover to the other side
  • Can coat low viscosity solutions
  • Lightweight cylinder means faster & easier changeover
  • Reverse coating creates shearing which results in a smoother surface
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Regular Gravure
  • Large contact area (a) and small web-to-roller (b) distance
  • Unstable bead of solution
  • Unstable coating
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MICROGRAVURE™
  • Small contact area (a) and larger web-to-roller distance (b)
  • Very stable bead of solution
  • Exceptionally stable, glossy and uniform coating

FACT

The world’s largest battery separator manufacturer in Japan developed their products using MICROGRAVURE™ technology, and they continue to manufacturer their separators using only the microgravure™ technology.

Yasui Seiki Workmanship

Yasui Seiki MICROGRAVURE™ rolls are made-to-order custom rolls. Each roll goes through numerous manual finishing procedures that are their trade secrets. Along with the finishing procedures, all meticulous physical, mechanical and chemical tests are manually done with extreme care by our Master MICROGRAVURE™ Engineer. Only Yasui Seiki can deliver full functionality of one-of-a-kind MICROGRAVURE™.

Application Examples

MICROGRAVURE™ is the method of choice in Japan for the coating process of multiple layers in LCD displays as well as touch screen components. This technology is predominantly used in essential electronics, such as smartphones, tablets, computer monitors and other LCD displays. 95% of the smartphones sold in the US contain at least one layer coated by MICROGRAVURE™ coating technology. MICROGRAVURE™ application is also rapidly growing in the Li-ion battery, photovoltaic solar cells, and window film industries.

OPTICAL
  • 0.005 to 0.015 μm AR/ LR coating on optical films
  • 2 to 3 μm hard coating on optical films
  • 14 μm photoresist coating for hologram application
BATTERIES
  • 0.5 to 1 μm carbon nanotube coating on aluminum foils
  • 2 to 4 μm insulation coating on porous separator films
  • 2 to 5 μm reflective coating for solar cells
PRINTED ELECTRONICS
  • 0.3 to 2 μm silicone coating on PET
  • 1 to 3 μm photoresist coating on PET

See Applications for more examples.

MICROGRAVURE™ Roll Mesh Volume

Mesh Reference wet Thickness (in microns)
R25 50 – 80
R30 30 – 45
R36 28 – 43
R38 25 – 40
R45 28 – 43
R50 25 – 35
R55 20 – 30
R60 21 – 31
R65 13 – 22
R70 20 – 30
R75 20 – 30
R80 12 – 20
R85 13 – 22
R90 8 – 16
R95 7 – 15
R100 6 – 14
R110 6 – 13
R120 5 – 11
R150 4 – 9
R180 3 – 8
R200 2 – 5
R230 1.5 – 3.5
R250 1 – 2
R400 Currently in testing phase

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