Biodegradable Hot Melt Adhesives Support Packaging Waste Reduction

By Alex Zulewski, Commercial Manager at Power Adhesives

Biodegradable hot melt adhesives facilitate simpler recycling and composting by removing harmful byproducts. Image courtesy of Power Adhesives.

Hot melt adhesives are a long-established staple of the packaging industry that offer several benefits over other carton and box closing systems. For one, they are faster to apply, more cost-effective, and non-destructive. However, with the growing focus on sustainability across the packaging sector, today’s corrugated and carton packaging converters find themselves needing more – they need innovations that can support them in enhancing recyclability and reducing waste.

Biodegradable hot melt adhesives offer the solution that the industry is looking for. Recent advances in adhesive formulation mean converters can now access hot melt products that are certified to break down naturally without compromising on performance. This technology is key to facilitating simpler recycling and composting by removing harmful byproducts from the equation and will provide a key tool for an industry seeking action on the environment.

Built Different

At a basic level, biodegradable adhesives are made from the same materials as traditional adhesive formulations. The key difference lies in the ability of the long-chain polymers to break down sufficiently. These are typically designed to last for the duration of the packaging’s operational life, but will begin breaking down after use when exposed to certain naturally occurring elements. The resulting mixture of organic material, carbon dioxide, and water can then be consumed by microorganisms in its entirety, similar to any other organic material. The result is an adhesive that will not degrade during use but can break down after disposal without leaving behind harmful waste.

Manufacturing this technology starts with careful raw material selection as manufacturers choose polymers, fillers, and additives that meet both performance and environmental criteria. The selected materials are blended to create a homogenous mixture at high temperatures, before being cooled and reformed into the desired shape. This formulation can be further processed to achieve desired properties such as enhanced bond strength or specific curing characteristics.

Today, biodegradable adhesives can achieve exactly the same performance as traditional adhesive products, with a high level of tack and fast setting that results in an almost instant bond once applied and compressed. This means they can be used with a wide range of uncoated cardboard and paper substrates for a variety of applications, ensuring brands and their converters can improve their packaging sustainability without compromising on efficiency or product quality.

It is important to confirm that any adhesive technology being promoted as biodegradable can actually biodegrade to the required standards. As a result, these adhesives are subject to rigorous certifications. The most common compostability standards are ASTM D6400, which is used in the US, and the European equivalent EN13432. These standards independently verify that certified products can completely biodegrade under industrial composting conditions and that they can disintegrate without leaving behind harmful substances. Such accreditation should be a priority for any converter seeking a biodegradable hot melt adhesive.

Helping Businesses Achieve Sustainability Targets

Biodegradable adhesives, such as first-to-market Tecbond 214B from Power Adhesives, represent a significant step forward in the pursuit of more sustainable packaging solutions. Image courtesy of Power Adhesives.

One of the key benefits of biodegradable adhesives is how they can help businesses support more effective recycling and reduce packaging waste. As a result, they present an increasingly appealing option for businesses looking to enhance sustainability and maintain compliance with the ever-changing web of regulations covering packaging and packaging waste.

Conventional adhesives cannot be recycled alongside packaging substrates due to the risk of contamination. After corrugated and carton packaging is collected and sorted, it is shredded into smaller pieces that are mixed with water to create a slurry. During this process, components including inks, coatings, and adhesives separate from the packaging fibers, and the pulp is filtered to remove these contaminants so it can be further processed into clean fiber-based materials. If left remaining in the pulp, these consumables degrade the final quality of the recycled product in terms of colour, consistency and performance, ultimately reducing its commercial value. Known as ‘stickies’, the contaminants can also accumulate on the recycling machinery leading to increased maintenance costs for recycling facilities. As a result, they are skimmed off and diverted to an alternative waste stream to be incinerated or landfilled.

Biodegradable adhesive formulations have additional benefits for regions with a lack of dedicated recycling or collection infrastructure. In an ideal world, all packaging would be collected and processed in recycling facilities after use but sadly, converters and brands cannot always control what happens to their packaging at the end of its life. Where recycling and collection infrastructure is underdeveloped, some packaging may end up being dumped. Should the worst happen, and packaging does enter the ecosystem, using biodegradable adhesives will grant peace of mind that it is not causing chemicals or microplastics to enter the environment.

Challenges and Future Outlook

Although biodegradable adhesives offer multiple benefits, there are still challenges to overcome relating to widespread proliferation. Ensuring consistent performance across applications and environmental conditions remains a key area of focus for manufacturers seeking to improve formulations. Additionally, scaling up production to meet growing demand while maintaining cost-effectiveness is an ongoing process. However, the future looks promising. Ongoing research is exploring new bio-based formulations that will further enhance the properties of biodegradable adhesives.

Sticking with the Environment

By offering a mixture of high performance and low environmental impact, biodegradable adhesives are already helping businesses to meet their sustainability targets and respond to growing consumer demand for more sustainable options. Their combination of strong bonding with the ability to break down naturally in the environment provides an invaluable tool for companies looking to reduce their ecological footprint and contribute to a more sustainable future.

About the Author

Alex Zulewski is the Commercial Manager at Power Adhesives. Alex leads the Power Adhesives Technical team covering NPD and R&D and played a large role in launching Tecbond 214B. Headquartered in Basildon, UK, Power Adhesives Ltd provides a full range of hot melt solutions to users around the world. As Europe’s leading shaped hot melt adhesive specialist, Power Adhesives offers the largest range of high quality, competitively priced hot melt glue sticks and adhesive applicators, with a selection of bulk hot melt adhesives available for high-volume applications. Power Adhesives products are sold under the Tec and Tecbond brand names, through an international network of specialist distributors. For more information, please visit www.poweradhesives.com