Most people would agree that a cup of coffee is great way to start the day, but not if the hot coffee ends up in your lap. A lot of people would also agree that fast food makes for an enjoyable meal, but not if grease or liquid from it ends up dripping on hands or clothes.

That’s where packaging comes in. Paper products for food packaging are a plastic-free, more sustainable option, provided they can keep grease, oil and liquids from passing through or weakening the paper and making a mess. Traditionally, paper packaging products have used a plastic lining to impart desired barrier properties.

For many years, manufacturers have used polyethylene (PE) plastic to coat cups and paperboard. Paper packaging with PE can be recycled, but it is difficult to do and requires a specialized facility. Polylactic acid (PLA) is a plant-based alternative that is biodegradable and compostable. But, for PLA to be composted, it must be industrially done in a specialized composting facility.

As the desire continues to build around using more environmentally friendly packaging and as regulations like the EU’s directive on single-use plastics are enacted, the need to develop paper-based packaging that is fully recyclable or easier to compost also continues to build.

Fully Repulpable and Recyclable

Lubrizol is committed to innovating coating technologies that enable new capabilities in the dynamic packaging market. In fact, over the last few years, coating technology has advanced to the point where it is becoming possible to replace plastic linings in paper packaging, making the packaging much easier to recycle while still delivering desired barrier properties.

One solution has been to use water-borne acrylic emulsions as a barrier coating. This added layer is applied by standard coating equipment as a liquid coating onto the paper and board applications in the food service market. The coating enables the paper to behave like a plastic package and remain functional in the application where used.

Paper and paperboard coated with these barrier coatings is fully repulpable so it can easily be recycled. End users can include them in a single-stream recycling bin or a paper or cardboard recycling bin, and they go through the same process as any other recyclable card or paper. They are also biodegradable, if they happen to not end up in a recycling bin.

Recyclability is an important end goal, but the coating has to also deliver the functionality required for specific applications beyond barrier properties (i.e., heat sealability, printability, food-contact compliance). The coated substrate must also be able to be processed with existing packaging manufacturing equipment.

Lubrizol’s Barrier Coating Solution

At Lubrizol, we’ve been working on addressing this issue for several years using our Carboset^® acrylic emulsion technology to replace the use of PE- or PLA-based barriers in paper-based packaging for the food service industry. Dispersion-coated papers and boards have proven to be effective alternatives in a variety of applications, including ready meal cartons and wrappers, ice cream cups, paper cups (hot and cold), and carton trays for frozen food.

One such product is Carboset^®GA 7513, which is a modified acrylic copolymer developed for the heat-sealable market with water barrier properties. It provides excellent Cobb levels using both room temperature water and hot (90ºC) water, and shows outstanding clarity when applied on paper. It has very wide heat-sealable windows that allows a high level of flexibility in formulating heat-sealable coatings for paper applications.

Replacing Plastic Linings With Packaging Barrier Coatings Using Acrylic Emulsions