Understanding coating applications is critical to getting the most out of an engraved roller. The coating process is truly individualized because it includes many variables, so this is only intended to provide a cursory overview to get you started. Please keep in mind that working with an experienced guide to finalize details is going to provide you with the best results. They can help you calculate the coating thickness you’ll need for your end product, transfer rates, and other factors.
Coating applications are typically applied using two methods. These are straightforward: the first method, direct application, is when the engraved gravure roller is making a direct transfer to the substrate. With the second method, indirect application, the engraved roller transfers the coating to a separate application roller that will, in turn, transfer the coating to the substrate.
The chemistry involved in your coating affects the roller volume required. Are you working with water based? Solvent? UV? EB? The flash-off of solvents and amines occurring with the use of solvent or water based coatings requires adjusting to a higher gravure roller volume.
There are three critical variables surrounding the coating application. They are the dry target coat weight, percent of solids and viscosity, and the specific gravity in lbs/gallon. When taken into account properly, these three can fine-tune your application to an impressive degree. Let’s take a quick look at each:
Dry target coat weight
- A major factor in recommending a line count and volume for the engraved roller
- Measured in lbs/ream or grams per square meter (gsm)
Percent of solids and viscosity
- As percent solid increases, volume required decreases
- Direct vs indirect transfer rate can vary up to a little over twenty percent
- Key in determining selection of roller volume
Specific gravity
- Measured in pounds per gallon
- As specific gravity increases, less volume required from roller
Visit our coating and laminating page on our website.
Experts at Pamarco have spent the last 75 years perfecting the science behind coating applications and the roller volumes best suited to your needs. If you are uncertain of the next step in the coating process, we would be honored to serve you by getting to know you, your particular situation, and helping you get the most out of your investments.
By Rick Spong, Northeast Sales Representative
Cell: 845-258-0185
Email: Rick.Spong@Pamarco.com