The Roll To Roll Slot Die Coating Basics You Need to Know

Interested in roll to roll slot die coating?

First step: Conduct preliminary research about the process. Great job! You’re already doing it.

Second step: Get more detailed answers by contacting a reliable manufacturer. Take, for example, Conversion Technologies International.

We’ll walk you through the basic rundown of the roll to roll methods. From there, our experts, located in the United States, have you covered. Let’s start now!

What is roll to roll coating?

When we utilize roll to roll coating, what we’re really doing is feeding a substrate from one roll to a secondary roll. We call this the “unwind to rewind” process. As we feed the the substrates from roll to roll, we’re able to apply fluids to the substrates. The rollers come pre-coated—as the substrate moves, the pressure prints, embeds, or laminates the fluid onto the substrate. It’s fairly efficient, and we can customize it as needed. Additionally, roll to roll coating allows us to cut down on waste.

Keep in mind that while we prefer primary and secondary rollers, in actuality roll to roll coating often involves several different rollers. This is the “web path”. The web path functions in several different ways, and it winds the rollers continuously.

How do we know that we’re using enough fluid? It’s pre-metered. The rollers themselves meter the coating as they work, which keeps the amount of fluid we use separate from the substrates. This cuts down on the potential for inconsistencies and unwanted variations.

We can, however, vary the type of rollers we use and the speed of the rollers, as well as the precision of the process, depending on what we need. Speed is one of the most important factors we consider as we conduct roll to roll coating. It can affect not only the efficiency of production, but the thickness of the coating.

What is roll to roll slot die coating?

To get more specific, let’s explore roll to roll slot die coating. To put it simply, slot die coating functions more simply than roll to roll coating—it’s essentially one step in the roll to roll coating process. In a slot die coating machine, we keep the slot die itself in a fixed position on the roll to roll line. As the substrate moves throughout the web path, the slot die applies fluid continuously. As such, we’re able to better avoid uneven levels of thickness. 

What are the advantages of specialized coating?

You’ll find several advantages of roll to roll coating. There’s a reason why this method is so popular amongst industrial manufacturers. Some of the most prominent benefits of roll to roll coating include:

—Less waste. As we mentioned earlier, this process cuts down on wasted product. Not only does it yield more consistent product, meaning you won’t have to discard of “duds”—it also takes less time to setup. You’re wasting less product and less time, thanks to the continuous nature of this strategy. For these reasons, roll to roll coating is also more sustainable. This contributes to a better world, of course; but on a more practical level, it’s also something many buyers and clients look for in the current day.

—Accurate results. Roll to roll coatings allow for greater precisions, which yields more accurate results. For the typical manufacturer, this is a huge advantage. Inferior products are both frustrating and inefficient. You don’t want to have to worry about the final product. The more accurate and uniform your results, the more easily you can move on to the next steps.

—Quality. Think about what your own clients may expect. Products created through roll to roll coating are crucial to the pharmaceutical industry, as well as the medical device field. They have strict expectations when it comes to quality, and this process empowers you to meet them.

—Cost cutting. Often, a more efficient process equals higher costs. Not when it comes to roll to roll slot die coating. Thanks to the continuous production involved, you’ll cut down on the time and steps needed. This means, ultimately, spending less money. It’s also easier to automate parts of this process, which means less labor. It’s a win-win!

What’s the difference between slot die coating and curtain coating?

When you first compare the processes, the main difference between roll to roll slot die coating and curtain coating is the distance between the substrate and the coating. The components of these methods are otherwise fairly similar. They both utilize multi-layer systems, and both require a great deal of precision.

The distance between a slot die and the substrate is essentially the thickness of the fluid coating. Curtain coating requires a greater distance. Additionally, the factors contributing to that distance include speed, density, velocity, and viscosity.

Roll to roll slot die coating and curtain coating serve different purposes. We use curtain coating to coat more irregular surfaces, which is why that distance is so important. For example, we’d address both glass panels and nonwoven substrates with curtain coating. 

Conclusion:

Like we said, the best way to learn further about this process is to consult directly with CTI. Fortunately, you don’t have to look far. Though we serve clients throughout the US, with everything from 10′ wide coating machines to large scale equipment, we’re based in Ohio. It’s easy for us to give you the answers you need, whether you’re working remotely or nearby.

You know what else is easy? Making that first contact. Reach out to us online here or give us a call at 419-924-5566. You’ll be on your way sooner than you’d think.