MICROGRAVURE™
Thin, Stable, Uniform Reverse Gravure Coating Method

US Patents D355,669 & D346,397

MICROGRAVURE™

FACT: The world’s largest battery separator manufacturer in Japan developed their coating technology using our MICROGRAVURE™ technology, and continues to manufacture their separators exclusively with our technology.


WARNING: Microgravure™ is a patented technology of Yasui Seiki. Yasui Seiki's genuine Microgravure™ undergoes a multitude of post-production processes that are not publicly shared. For this reason, Microgravure rolls manufactured by companies other than Yasui Seiki consistently underperform compared to the genuine Yasui Seiki Microgravure™.


What is MICROGRAVURE™?

A smaller diameter gravure roll, engraved with cells of varying depths, is designed to deliver a specific coating volume. This roll is used in a reverse kiss coating method, where it is partially submerged in a solution pan. As the roll rotates opposite to the web’s direction, it picks up the coating solution in its cells. A flexible doctor blade gently removes any excess, ensuring that only the precisely measured solution from the cells is transferred to the web.

Microgravure

Why is MICROGRAVURE™ better than regular gravure?

  • Enhanced Stability for Thin Coatings: The smaller diameter of the Microgravure roll provides a much smaller contact area (a), which allows for an exceptionally stable bead of solution. This stability is critical for achieving thin, uniform, and glossy coatings, as it prevents variations and disturbances in the coating fluid.
  • Improved Clarity and Cleanliness: The larger distance between the web and the roller (b) minimizes streaks and promotes cleaner lines. This increased separation reduces the likelihood of mechanical interference that can cause imperfections in the coating application.
  • No Backing Roll Benefits: The absence of a backing roll means there is no creasing and a smaller contact area, which helps in preventing the spillover of the solution to the other side of the substrate. This feature is particularly beneficial for sensitive materials and precision applications.
  • Versatility with Low Viscosity Solutions : Microgravure is specifically adept at coating low viscosity solutions. Its design ensures even and consistent application of very fluid materials without dripping or uneven spread, which can be a challenge with traditional gravure methods.
  • Efficiency with Lightweight Cylinder: The lightweight cylinder of the Microgravure system facilitates faster and easier changeovers. This reduces downtime between jobs, enhancing productivity and allowing for a more agile production environment.
  • Smoother Surface with Reverse Coating: Reverse coating, a technique where the cylinder rotates in the opposite direction to the web, creates shearing forces that result in a smoother surface finish. This shearing helps to evenly distribute the coating material and eliminate textural irregularities.
Microgravure
Regular Gravure MICROGRAVURE™
Large contact area (a) and small web-to-roller (b) distance Small contact area (a) and larger web-to-roller distance (b)
Unstable bead of solution Very stable bead of solution
Unstable coating Exceptionally stable, glossy and uniform coating
Backing roll causing issues No backing roll
Limited viscosity range Extremely low viscosity coating
Irregular surface Extremely smooth surface

What experts say about this? Read more...


What can MICROGRAVURE™ do?

  • Exceptional Uniformity: Microgravure™ offers outstanding uniformity with a tolerance of ±2%. This precision is critical for applications requiring consistent thickness across a wide surface area, reducing material waste and ensuring high-quality results.
  • Versatile Coating Thickness: Capable of coating layers from 0.5 to 80 microns when wet, and achieving as thin as 5 nanometers once dry. This range allows for flexibility in application, from ultra-thin protective layers to more substantial functional coatings, accommodating a broad spectrum of industrial needs.
  • Adapts to Various Viscosities: Efficiently coats low viscosity solutions ranging from 0 to 200 centipoise (cP), and is compatible with both aqueous and solvent-based solutions. This adaptability makes it suitable for diverse industries, from pharmaceuticals to electronics, where different material properties are essential.
  • Wide Range of Substrate Compatibility: Microgravure™ technology is versatile enough to coat on a variety of thin substrates including PET (polyethylene terephthalate), PC (polycarbonate), PP (polypropylene), aluminum, copper, stainless steel, paper, non-woven materials, porous substrates and fabric. This capability ensures its applicability in various sectors such as batteries, packaging, electronics, and textiles, where different substrate characteristics are key to product performance.

What materials MICROGRAVURE™ come in?

  • Hard chrome over special steel alloy
  • Hard chrome over nickel underplate over special steel alloy
  • Winkote® DLC (diamond like carbon) over special steel alloy
  • NEW!! Winkote® DLC (diamond like carbon) over stainless steel (SUS304)
  • NEW!! Hard chrome over stainless steel (SUS304)

Where can I try MICROGRAVURE™?

  • Yasui Seiki's Coating Service facility in Bloomington, Indiana, MIRWEC Coating, offers coating trials using many different size MICROGRAVURE™.

  • Our smallest R2R lab coater, Mini-Labo™ is equipped with MICROGRAVURE™

Yasui Seiki Workmanship

Yasui Seiki MICROGRAVURE™ rolls are custom-made to order. Each roll undergoes numerous manual finishing procedures that are our trade secrets. Alongside these finishing procedures, all meticulous physical, mechanical, and chemical tests are manually conducted with extreme care by our Master MICROGRAVURE™ engineers. Only Yasui Seiki can deliver the full functionality of our one-of-a-kind MICROGRAVURE™ technology.

Master MICROGRAVURE™ Engineer
Master MICROGRAVURE™ Engineer, Fumio Koizumi
MICROGRAVURE™ Inspection 1
MICROGRAVURE™ Inspection 1
MICROGRAVURE™ Inspection 2
MICROGRAVURE™ Inspection 2

Application Examples

Yasui Seiki MICROGRAVURE™ is the preferred method in Japan for coating multiple layers in OLED displays and touch screen components. Our technology is predominantly used in critical electronics, including smartphones, tablets, computer monitors, and other OLED displays. Remarkably, 95% of the smartphones sold in the US contain at least one layer coated by one of our MICROGRAVURE™ machines. Over the past five years, MICROGRAVURE™ has demonstrated unparalleled performance in every layer of Li-ion battery coatings, including anodes, cathodes, and separators. Additionally, the application of MICROGRAVURE™ is rapidly expanding in industries such as solar cells (photovoltaics), wearable medical devices, and state-of-the-art optical films.

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 application examples.


Smartphones
Lithium-ion Battery
Photovoltaic

MICROGRAVURE™ Mesh Chart

Mesh Average Wet Thickness (μm)
R20 56.3
R30 44.6
R36 42.0
R38 37.1
R45 47.0
R50 30.1
R55 23.6
R60 32.0
R70 22.0
R80 20.0
R90 14.7
R100 10.2
R110 9.6
R120 9.5
R150 6.7
R180 5.5
R200 3.6
R230 2.7
R250 2.1

Contact Us for custom mesh sizes