In the first two blogs in this Flexible Film series, we covered “Laser Coding on Flexible Films” and “When to use CO2 (D-Series) versus Fiber (F-Series)”.
In this third blog, we are going to highlight an upcoming transition / evolution of flexible films for sustainability reasons and how this could affect laser coding. We are seeing a clear industry mandate to move away from multi-layer films. Companies who use these films are highly motivated to transition to a more environmentally-friendly alternative.
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The primary films for packaging include Polyester (PET), Polyethylene (PE), Polyvinyl Chloride (PVC) and Polypropylene (PP). These films each have very different properties and characteristics as it relates to packaging functionality. For example, PET has good oxygen and moisture barrier properties, but it doesn’t seal well. PE seals well but doesn’t have good oxygen barrier properties. PP has a good moisture barrier and a high melt temperature, but it is not a good oxygen barrier.
Each film features different capabilities and characteristics that make them suitable for specific applications. However, most often these films are combined to create multilayer films which can provide the desired combination of functionality not available in a single film. For example, when PET and PE are combined in a multilayer film, you get the great barrier properties of PET and the excellent sealing properties of PE.
The versatility and affordability of multilayer plastic films have created a large demand for them. Multilayer films enable the film supplier to customize a combination of films to provide the exact functionality required for the product being packaged. Multilayer films have solved numerous packaging challenges. However, multilayer films have also created another challenge - they are typically not able to be recycled using traditional plastic recycling technologies (like mechanical recycling) owing to the chemical incompatibility of the different layers.
The Drivers of Change impacting substrates
Sustainability has become a primary area of concern for both producers and consumers. Consumers increasingly expect producers to operate in an environmentally friendly way and are using their buying power to influence this behavior. Plastic waste is highlighted as one of the biggest sustainability issues the world is facing today. The 25 largest CPG (Consumer Packaged Goods) companies, who also happen to be customers of Domino, have committed to efforts to convert to recyclable, reusable, or compostable packaging by 2025. And many are following suit.
Taking the first step
Laser coding is highly dependent on the characteristics of the material being marked. How the material absorbs and reacts to the laser energy will determine the coding characteristics on that material. In the next 3 years, thousands of production lines will transition to new packaging films. A critical step in this process is validating that the new film will code as well, or better than the original film. This is a process which you need to conduct with experts familiar with laser/matter interactions and the pertinent material science.
You will want a full validation of the laser application with the new film type(s) as a baseline for your records. A complete report showing not only the code quality but also the maximum potential throughput, duty cycle, etc., at your full production parameters. You will also want evaluations performed with more non-traditional laser wavelengths, which could provide real advantages with this new material. As soon as new film, or similar film is available, have your laser supplier begin evaluating the laser interaction. If possible, foster direct collaboration between your laser and film supplier. Use the expertise of a real laser lab as an extension of your own engineering resources. Your engineers are going to be plenty busy introducing and testing new film types in production and determining the full compatibility with the existing equipment and production requirements.
If multilayer films are the challenge, then mono-films may be the answer. However, there are further challenges associated with the transition from multilayer to mono-layer packaging films. Thin layers of materials in multilayer flexibles provide beneficial properties. This enabled the development of lightweight, efficient packaging solutions.
Mono-material flexible packaging can also be produced as lightweight solutions. However often having inferior barrier properties and potentially yielding shortened food shelf-life and food waste. According to FeedAmerica.org, "In the United States roughly 40% of all food is thrown away amounting to over 108 billion pounds of food is wasted in the United States. The estimated total value of food loss at the consumer and retail level is $408 billion per year. Countering the barrier property inefficiencies can necessitate greater film thickness and therefore weight increases which also can also have negative environmental consequences.
There are some real challenges in transitioning to mono-films and reproducing the functionality of the multilayer films. However, we are already beginning to see an increased number of packaging film suppliers offering more sustainable, more eco-friendly products. With tag lines like “Let us help your brand fulfill its sustainability goals and lessen its carbon footprint by choosing from our sustainable packaging product line”. Necessity is the mother of invention and I’m confident the film suppliers will continue to rise to the occasion. Also, thank you to these CPG companies who have committed to doing difficult things for good reasons, like the sustainability! We are proud to be a part of that process.
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