Micro-gravure roller is a precision coating roller specifically designed to achieve ultra-thin, high-uniformity coatings. Essentially, it represents a miniaturized and high-precision improvement of traditional gravure coating technology. Operating through a unique "reverse kiss-coating" principle, it is one of the core components for manufacturing high-end products such as optical films, lithium batteries, and touch screens.

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Core Working Principle and Structure

The coating process of Micro Gravure Roll is a precise closed-loop system of "metering and transfer":

*Small diameter roller: Compared to traditional gravure rollers, micro-gravure rollers have a very small diameter, generally ranging from Φ20mm to Φ60mm. This characteristic results in a very small contact area with the substrate, enabling the formation of extremely stable coating droplets, which is crucial for achieving thin coatings.

*Reverse kiss coating: During coating, the rotation direction of the micro-concave roller is opposite to the feeding direction of the substrate (such as film, copper foil). This reverse shear action helps to scrape the coating smoother and improve transfer efficiency.

*Back pressure roller-free design: Unlike traditional coating methods that require rubber back pressure rollers, the micro-concave roller adopts a "kiss coating" method, where the substrate directly contacts the roller surface without the need for a back pressure roller. This completely avoids wrinkling and backside contamination issues caused by pressure on the substrate.

Key Performance Parameters

Performance metrics	Technical Specifications	Instructions
Coating uniformity	±1% ~ ±3%l	Higher than traditional coating
Wet film thickness	0.5 ~ 80 μm	Covering a wide range from extremely thin functional layers to thicker protective layers
Dry film thickness	Can be as thin as 5 nm	It can achieve ultra-thin coatings at the nanoscale, such as optical anti-reflective coatings
Viscosity	0 ~ 1000 CP	TParticularly adept at handling low-viscosity, easily flowing solvent-based coatings
Speed ratio control	1: 1.3 (Roll speed: Line speed)	Most stable and uniform coating effect can usually be achieved

Application areas and advantages

With its high-precision coating capability, Micro Gravure Roll is widely used in high-end manufacturing

Photovoltaic display

Used to manufacture various optical functional layers for LCD displays and touch screens in smartphones and tablet computers. According to data, at least one coating layer in 95% of smartphones sold in the United States is completed using micro-concave coating technology.

New energy

In lithium-ion batteries, it is used to apply a carbon nanotube coating (0.5-1μm) on aluminum foil or an insulating layer (2-4μm) on the separator.

Other fields

It is also used in the production of solar cell reflective coatings, window films, car protective covers, medical tapes, and other products