Hotmelt Coating: Its Benefits And Why You Need To Utilize It

When it comes to coatings, you’ll inevitably have a wide variety of processes to choose from. Before you set to work with a roll coater machine, it’s crucial to know exactly what you’re getting yourself into. Enter: hotmelt coating!

While hotmelt coating isn’t the perfect coating method for every project, it does offer certain benefits that we can’t ignore. And though it may sound intimidating at first, it’s actually a fairly straightforward process. 

What is the process of hotmelt coating?

On the most basic level, hotmelt coating is a process we use to strengthen materials and make them more durable. These coatings exist to protect the surface upon which we apply them. In this case, we use an initial polymer layer, which we apply to the surface with extrusion, melting, and calendaring. As we do this, the hotmelt material flows between two different rolls. Through this process, we bond the melted layer into the surface. It also allows us to control the thickness of the layer. In the last steps of the process, we cool the product, hardening that coated polymer layer.

This comes with specific benefits:

Durability. As previously mentioned, hotmelt coating adds a great deal of durability to your product. It’s protective, hardening the product and adding scratch-resistance. In some cases, it offers a level of UV protection as well.

Welded connections. This coating literally weds materials together. The heated quality enhances the connections even further.

Flake-resistant. Some coatings flake off, which not only chips away at that durability but creates a mess. Plus, it’s pretty unsightly! Hotmelt coatings tend to be flake-resistant, which also means that you don’t have to redo them quite as frequently.

The main alternatives to hotmelt coating are solvent coatings, some of which include water. While these water-based coatings need to dry, hotmelt coatings don’t require nearly as much time to solidify. You’re not just saving time–you’re saving energy as well. On the other hand, solvent coatings without water may dry faster, but are chemically more volatile.

In general–you’re getting more bang for your buck with hot melt technologies, and they tend to be easier to apply. It’s no wonder that we rely on these coatings for so many types of projects.

What are examples of hot melt adhesive?

We compose your average hot melt coating with specific types of adhesives. These include:

Ethylene vinyl acetate. Usually, we use EVA for general purpose bindings, which makes it one of the most common types of hotmelt adhesives. A copolymer adhesive, EVA most commonly applies to paper, assembly industries, and packaging. This is because it bonds to a variety of different cellulosic materials, with corresponding formulations. We can alter the makeup of these formulations to work with coating machines and provide the desired result.

Mettalocene. Sometimes referred to as mPO, mettalocene works when a project needs a high level of strength with small quantities of product. It’s actual metal catalyzed polyethylene, and works best for case and carton sealing and packaging. Usually, an mPO coating provides more durability than an EVA coating–and many prefer the look as well.

Polyamide. Typically, these coatings require a higher degree of heat during the coating process. However, they also tend to be more heat resistant.

Polyurethane. When you select this type of hot melt adhesive film product, you’re looking for elasticity and flexibility, as well as excellent resistance to grease, oil, and abrasion. While this option won’t work for every project–for those it does, it’s highly prized. Another thing that sets it apart from other options is that it absorbs small amounts of moisture as it solidifies.

Latex. These adhesives, which offer a good level of durability, tend to solidify very quickly. Therefore, if you’re trying to scale up or move your assembly line at a faster rate, latex adhesives may be a better option.

Polyolefine. Although very acid resistant, this adhesive is only moderately resistant to heat. However, it sets quickly and tends to be fairly inexpensive. For that reason, you may want to pair it with a slot die coater.

What types of materials do we use when hotmelt coating?

When utilizing hot melt technologies, we focus on a few different base materials. Some of the main bases we use for hotmelt coating include olefin, polyamide, and polyester. Usually, we either bond-process them, or process them into slit tape. No matter what type of hotmelt coating you decide upon, the right base material is key.

Fortunately, even if you aren’t certain about which methods or solutions are right for you, experts are ready to help. Often, it’s recommended that business owners work with third party manufacturers. Third party manufacturers offer streamlined systems, making it easier to scale up and offer a more efficient production schedule. Additionally, experienced manufacturers like Conversion Technologies International offer guidance when needed. We have the insights you need.

While it may initially feel difficult to outsource manufacturing processes or equipment like a coating machine (we get it!) you’ll appreciate the benefits. Not only does third party manufacturing make your systems more efficient–it also cuts costs.

In conclusion:

Mastering hotmelt coating isn’t necessarily easy, but it’s an important process. The right hotmelt coating can strengthen and perfect your product. Fortunately, working with a third party manufacturer ensures that you’ll not only choose the right process, but have it executed correctly. To learn more, contact CTI here or call us at 419-924-5566. We’re ready to assist!