Flexible packaging is very popular due to versatility and marketability of the structures. Flex packaging serves a variety of markets, with a large share found in the food sector, most likely due to the packaging’s ability to be resealed. It’s also lightweight, efficiently transported and provides a very visible brand billboard at retail. Along with these traits is the perception that flexible packaging can be recycled. This is true, but design and material selection must follow some guidelines to produce a recyclable package.
One of these things is not like the other…
In simple terms, most flexible packaging for the food sector is comprised of at least two layers of plastic material. This is because one type of material is excellent for printing and for heat sealing of the package once its filled with product, but not very good for protecting food contents from oxygen and water vapor. Thus, a second film layer, a ‘barrier’ layer, often a different material than the print layer is laminated to the print layer to provide protection from water and air. And that is when recycling becomes more difficult if not impossible. When two different plastic materials are formed into a flexible package, it prevents recycling by current processes and technology.
High and Low-Density Polyethylene
Designing a package utilizing a single plastic material for both the print and barrier labels is the key to enabling recycling. But how do we accomplish this when we need to have at least two different materials to meet the printing and product protection requirements of the package? The answer is to use one ‘base’ material with different density levels. Utilizing high-density polyethylene (HDPE) for the print layer, and low-density polyethylene (LDPE) for the barrier results in a package made of one base material (PE). HDPE has characteristics that make it very receptive to printing. It also has a high level of clarity, and it will not stick to heat-seal machinery components during the converting process. The sealant layer is an LDPE that has been coextruded with an internal barrier layer needed for dependable food packaging.
When the two layers are combined, you get a material that can be printed and converted into flexible packaging without causing issues with the pouch converting machinery. And again, since the entire package is PE based, it’s readily recyclable.
There’s more to sustainability than recycling…
So, we have a totally recyclable pouch that meets the requirements of product protection and looks great doing it. But that’s not the end of the sustainable story when it comes to flexible packaging. This packaging format has a lot more going for it. Life Cycle Assessment tools show that flexible packaging can result in less fossil fuel usage, greenhouse gas emissions, and water than other packaging because of its light weight. Flexible packaging materials are usually shipped flat or on a roll. This means a larger number of packages can be shipped in one truckload, reducing the number of truck trips needed when compared to a bulkier, heavier package. Flexible packaging also scores well on the ‘product-to-package’ ratio – a measure of how much of a packaged product consists of packaging compared to the actual product (by weight).
This is a blog post, and obviously a high-level explanation of what’s needed to create recyclable flexible packaging. For a more thorough explanation of the process, or to explore sustainable solutions for your brand’s package, talk to the experts at AWT.