Aqueous Coating – The Role It Plays in the Packaging Industry


Aqueous coating is one of the most critical processes in packaging and can play many different roles. To fully understand its role, it’s essential first to learn what aqueous coating is and how it works in the context of the packaging industry. The aqueous coating, or over-coating or end-coating, is an outer protective layer that applies directly to the product being packaged or shipped. Let us discuss in detail all the essential aspects of that process and how it impacts the latest industry trends.

The Need for Aqueous Coating

Safety and the packaging of food items have become more advanced than ever. No doubt that is with good reason. That is where the never-ending need for aqueous coating enters the scene. 

Consumers want to be sure that the food they buy is safe and that it will last long enough to reach them when purchased, as well as enjoy the taste of the food once it arrives at their homes or dining tables. 

A box with an extra coating layer will be safer and sounder than a box with no such protective layer. That is why most vendors prefer to get it for their personalized boxes.

Other industries have used the aqueous coating for years, but recently the demand for this material has grown dramatically in other markets. Regarding packaging materials for custom boxes, there is an extensive list of options available to the packaging design industry. Let us elaborate on that aspect with the help of various types of aqueous coatings.

Let us further explain its benefits in the packaging industry:

Perks of Aqueous Coating in Packaging

Many think of a coating only used for decorating or protecting packages, but that’s not necessarily true. Coated paper has a wide range of uses, from printing, barrier protection, heat salability, and improved scuff resistance, to name a few. In some cases, paper is coated multiple times with different materials for different reasons. There are other techniques, such as Embossing and Debossing, but the aqueous coating is the most suitable one.

Coatings are also used on flexible material like Tyvek or Stretch Film and other substrates like PVC film and Polyester. For example, an aqueous coating can be added to provide antibacterial properties or UV protection for specific products. Of course, any package can benefit from an aqueous coating, so you should never assume your package doesn’t need one!

However, it does not mean that it is an all-beneficial process. There are also some disadvantages to that process. For instance, the most significant negative aspects are as follows:

Disadvantages of Aqueous Coating

One of its most significant disadvantages is that aqueous coating is not very durable. Due to its weak bond, a glass surface can be scratched easily, and oils from your hands will stain it. Glass coated with an aqueous solution also has feeble resistance to moisture, which makes it vulnerable to breakage or staining by things like humidity and weather conditions. Finally, because no pigments are involved in an aqueous coating process (no color added), there is no way to change the Glass’s natural color or hide potential imperfections. Due to this reason, some might prefer Spot UV instead.

Different Types of Aqueous Coating

There are different types of aqueous coating. Among those are lacquers, enamels, and polyurethanes. Lacquers, for example, give a glossy finish to any object. Polyurethanes form clear coats that protect objects from wear and tear.

However, the abovementioned types are all for the technical and automotive industries. When we talk about the field of packaging, we have the following types of aqueous coating.

Gloss Coating

A gloss coating consists of two layers; a primer and a topcoat. The primer provides adhesion while ensuring moisture resistance while maintaining a printable surface. Gloss coatings are available in solvent-borne and waterborne options to accommodate product needs. Most solvents used for coating formulations are either VOC or greenhouse gas-exempt.

Matte Coating

Matte is a type of coating that offers a dull finish to the paper. This makes matte coating ideal for uncoated papers and can also give extra bulk to cardstock, allowing your cards to be sturdier. Another way we can use matte coatings is to add shine to otherwise dull papers or surfaces. For example, many graphic design firms have used glossy paper for marketing materials but switched to matte coatings because of budget constraints. Matte coating is an inexpensive alternative that offers almost as much glossiness as glossy paper does!

Dry Erase Coating

There are numerous products available for making dry-erase boards. Some are semi-permanent, meaning that if you don’t like how they look, you can easily change them or cover them up with something else. Others are more professional coating, meaning they will not come off once applied unless you want to remove them permanently.

Satin Coating

What is Satin Coating? – First and foremost, the satin coating doesn’t have to do with cosmetics. Instead, it has to do with paper products like books, magazines, flyers, and business cards printed using inkjet technology. Also known as satin varnish or satin coating, a satin finish on such items gives them an elegant appeal while protecting them from wear and tear.

Soft Touch Coating

Aqueous coating, also called soft-touch coating, often referred to as aqueous, is a thin protective lacquer sprayed onto a package (which includes glass bottles and metal cans) with high pressure. It leaves behind a micro-thin barrier layer that helps maintain the freshness of food products, protects them from scratches during shipping, and provides additional protection against tampering. Aqueous lacquers can also be applied over a glass or metal containers after they have already been sealed.

Process of Aqueous Coating and How to Apply It

A coating or lacquer is a substance applied to a surface area for protection, luster, or decoration. Aqueous coating involves using water as an application media. This process requires two coatings. To make an aqueous coating, you will need water and ammonia nitrate. Add one part water to one part ammonia nitrate and add pigments if needed. Mix until transparent and apply to paper, cloth, or any substrate that needs preserving against wear and tear due to weathering conditions.

Is Aqueous Coating and UV Coating the Same? What is the Difference

Aqueous coating and UV coating are similar processes. Both cover a surface to make it less permeable to contaminants and moisture. In short, UV spray is what you’ll hear most people call a waterless wash. While both of these processes have their benefits, one significant advantage makes aqueous coating so popular, and that is no other than the economic aspect. Aqueous (water-based) coatings are much less expensive than UV coatings because they require significantly less production energy and typically don’t need curing equipment or lamps.

Why Prefer Aqueous Coating Over Other Techniques?

The aqueous coating uses water to spray polymers onto substrate surfaces; traditionally, a typical spraying technique uses oil to suspend polymers. However, oil-based polymers tend to oxidize when exposed to light and air for extended periods, reducing their performance over time. That makes aqueous coating a more favorable option than Foil Stamping.

Additionally, oil suspensions can produce unwanted foaming at the point of application or on storage. However, water prevents oxidation while producing minimal foaming; as such, you should expect better performance with aqueous coatings than with oil suspension. Note that not all polymers need an aqueous suspension to maintain optimal performance.

How to Choose a Manufacturer for Aqueous Coating?

When choosing a manufacturer for aqueous coating, there are several factors to consider. For example, have they worked with someone from your company before? Have they established a company? Are they easy to get a hold of, or does it take them forever to reply to emails? You will also want to ensure that their turnaround time for jobs is acceptable and that you’re comfortable working with their customer service team. 

Make sure you research companies as much as possible and speak to as many former customers as possible before deciding which one is right for your project.

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