Why should replace plastic packaging with paper?

When it comes to packaging and environmental awareness, there are two important questions to be asked: "What types of packaging are considered sustainable?" and "How can packaging be made more sustainable?". ELITER Packaging Machinery talks about the plastic replacement in the packaging industry.

Plastic is a simple sustainability goal, as it takes a long time to degrade, that is, it can remain in landfills for hundreds of years when discarded. But, if recycled, plastic becomes less problematic, although some types of plastics are difficult to recycle.

Excessive or unnecessary packaging is the first level of unsustainable packaging. From there, packaging that is not easy to recycle is a problem (that is, combined materials that cannot be separated, such as snack bags, styrofoam cups, packaging with plastic coatings, such as coated cups and wrappers).

To fully understand which type of packaging is more sustainable, a complete circular economy analysis would be needed. It should take into account factors, such as the energy used to manufacture and recycle the material, the amount of space occupied by the packaging and the relative weight of the different packaging and, therefore, transport costs, how much material is used in the different formats, etc.

What happens to biodegradable materials? This will simply degrade on earth and return to the ground, will it? Well, only in certain cases, what is usually called industrial composting. There are only a limited number of industrial composting centers in many countries at the moment.

Many brands, taking into account the various sustainability issues, want to replace plastic or plastic-coated packaging with paper-based packaging that can be recycled more easily.

Desired protective properties

The challenge of paper-based packaging is that it does not have the same protective properties as plastic (with respect to water, moisture, grease, gas, odor), so it is usually treated with a protective coating to improve performance. A protective layer is an additional layer that is applied as a liquid coating on the substrate to provide greater functionality. The objective is to allow paper to behave mostly in the same way as plastic packaging and to remain functional in the application in which it is used.

Without a protective treatment, a paper coffee cup would start leaking hot coffee soon, packaged snacks would lose their crunch, as moisture would penetrate the packaging; fast food trays would absorb fat that would pass to the hands or surfaces, sauces would drip from the containers or the food would spoil more quickly with the penetration of oxygen. Not all packaging requires a high level of protection, and paper cannot replace plastic in all applications. But, to replace many of the applications where plastic is used with a paper-based alternative, the properties of paper can be improved with protective coatings.

While the concept is sound and the intentions are good, another concern is that most of the protections currently used to make paper-based packaging behave more similarly to plastic and prevent paper from being recycled.

A more sustainable protective solution

Water-based polymeric coatings can overcome such a problem. They can offer some of the desired protective properties and, at the same time, allow the paper to remain repulpable, which achieves the reduction of plastic use and greater recycling capacity.

In addition, there are no special aspects to consider when using water-based polymer coatings for this purpose. The application of the coating can be a fundamental step to achieve the necessary performance. The coating must also offer the necessary functionality for the specific applications beyond the protective properties (i.e. heat sealing, printability, food contact compliance) and the coated substrate must be processed with the current packaging manufacturing equipment. For example, the cup coating material (the paperboard used to produce the paper coffee cups) should be sealed at the same speed and temperature as used with the plastic-coated cups, so that the cup production efficiency can be mostly maintained.

The initial costs of the coating may be higher than the plastic it replaces because the polyethylene layer is a raw material, but there are many other aspects that must be taken into account when analyzing the total cost: relative overall production costs, the ability to recycle industrial waste, the ability to recycle waste after consumption, the exemption from packaging taxes and the improvement of the brand image and the possible increase in sales following this improvement for a company implementing sustainable packaging solutions.