Consistent screen coating is one of the most important parts of the screen printing process. If your emulsion thickness changes from screen to screen, your exposure times, stencil quality, and print results can change too.
That is where automatic screen coating can make a big difference.
In this Blue Ridge University video, we take a closer look at the Grunig G-COAT 406 automatic scoop coater, including the machine layout, basic functions, and key settings used to create more repeatable coating results.
What Is the Grunig G-COAT 406?
The Grunig G-COAT 406 is an automatic coating machine designed for one-sided or double-sided screen coating. Instead of manually coating each screen by hand, the machine helps control the coating process so shops can get more consistent results across multiple screens.
According to Grunig’s product brochure, the G-COAT 406 is designed as a compact, low-maintenance automatic coating machine and is available in two sizes for screens up to 700 x 1000 mm or 1000 x 1400 mm.
For shops that coat a lot of screens, automatic coating can help reduce variation from one operator to another and make the screen room process more predictable.
Why Consistent Screen Coating Matters
A good stencil starts before exposure.
If a screen is coated too thin, too thick, unevenly, or inconsistently from one side to the other, it can create problems later in production. Common issues include:
- Inconsistent exposure results
- Weak stencil durability
- Poor edge definition
- Pinholes or uneven coverage
- Trouble repeating the same results from job to job
Manual coating can work well when done properly, but it depends heavily on the person coating the screen. Angle, speed, pressure, scoop coater condition, emulsion level, and technique all affect the final result.
An automatic coating machine helps standardize more of that process.
Key Settings on the G-COAT 406
One of the main advantages of the G-COAT 406 is that coating parameters can be programmed through the control panel. The machine allows users to adjust important settings like:
- Coating speed
- Number of coatings on the squeegee side
- Number of coatings on the print side
- Flow time
- Frame profile height
The brochure lists the coating speed range at 15–65 mm/s, coating counts from 0–10 on both the squeegee and print side, flow time from 0–10 seconds, and frame profile height from 25–100 mm.
These settings give shops more control over the coating process and help make results easier to repeat.
One-Sided or Double-Sided Coating
The G-COAT 406 can be used for one-sided coating or double-sided simultaneous coating. This is especially useful for shops that want more control over stencil build and coating consistency.
Double-sided coating can also help improve workflow by allowing the machine to coat both sides of the screen in a controlled process rather than relying on manual technique.
Who Is Automatic Screen Coating Best For?
Automatic coating is not always necessary for every shop. Smaller shops may still get good results with manual coating if their process is dialed in.
However, the G-COAT 406 may be a good fit for shops that:
- Coat a high volume of screens
- Need more repeatable stencil results
- Have multiple employees coating screens
- Want to reduce screen room variables
- Struggle with inconsistent exposure results
- Print detailed artwork or tighter registration jobs
- Want to improve overall screen room workflow
For growing shops, consistency becomes more important as production increases. Automatic coating can help remove some of the guesswork from the screen-making process.
Better Coating Supports Better Exposure
Coating and exposure go hand in hand.
Even if you have the right emulsion and exposure unit, inconsistent coating can still create inconsistent results. A more repeatable coating process helps make exposure testing more accurate and makes it easier to troubleshoot stencil problems.
If your shop is having exposure issues, it is worth looking at the full process:
- Mesh count
- Emulsion type
- Coating technique
- Drying conditions
- Exposure time
- Washout process
- Reclaim process
The G-COAT 406 helps address one of the biggest variables in that process: how consistently the emulsion is applied to the screen.
Watch the Full G-COAT 406 Overview
In the video above, we walk through the Grunig G-COAT 406 and review the main settings used during operation. This is a helpful starting point for shops that are considering automatic screen coating or want to better understand how the machine works.
For questions about the G-COAT 406, screen room setup, emulsion selection, or exposure troubleshooting, contact the Blue Ridge Screen Products team.
