Plastic Recycling Essentials

How Milliken Supports Every Step of an Effective Plastic Recycling System

For many people, recycling seems like it should be simple. Make the product, use the product, recycle the product, make a recycled product—it's as simple as that. Except it's not. According to The Recycling Partnership, the United States loses 79% of recyclables to landfills each year. When you take a step back, it's more complex, requiring participation from consumers, suppliers, manufacturers and brands to truly be successful. If you work with an organization that has made promises or set goals that include using more recycled materials in your products, it's critical you understand the complexity of the entire process and the role of new technologies in overcoming these challenges.

For example, take into consideration that less than half of plastic packaging is recyclable 1. Not only does that make it impossible for proper recycling access, engagement, and sorting to happen, it dramatically impacts the availability of materials to companies and brands who have pledged to use more recycled material in their packaging.

In their 2024 State of Recycling Report, The Recycling Partnership outlined five requirements to an effective recycling system, which would allow American consumers to adopt better recycling practices and in turn, decrease the amount of plastic sent to landfills and instead be reused or recycled. In the below illustration, The Recycling Partnership outlines the five requirements that need to be met.

With this information in hand, the question then becomes how do suppliers and partners at every stage of the supply chain support these five requirements?

At Milliken, we understand that without addressing every gap in the system, the system won't succeed. Using our science expertise, partners, and product portfolio, here's how we're helping to address each and every one.

Requirement #1: Packaging Recyclability

Not all materials are recyclable. The first step in the process is choosing a packaging material that has the potential to be recycled. There are not only multiple types of plastic, but there are also various ways to produce or enhance the multiple types of plastic resins. Milliken offers additives that help high-density polyethylene (HDPE) or polypropylene (PP) producers and converters get features not traditionally found in other materials. These additives, including UltraGuard™ and Millad® NX® 8000; Millad® NX® 8000, enable benefits like barrier protection and high clarity in a mono-material HDPE or PP solution. This can in turn enhance the packaging’s recycling compatibility. Additives are also important in a packaging’s compatibility with recycling processes. Milliken additives, like Millad® NX® 8000 Eco, makes PP products look like glass—and has been confirmed fully compatible with PP recycling processes in Europe by RecyClass.

If you’re responsible for considering circularity in product development, The Recycling Partnership’s 2024 State of Recycling Report can help you.

Requirement #2: Recycling Access

Let’s pretend suppliers and brands find a way to make every single plastic product recyclable. Time to celebrate right? Not so fast. Without consumers having proper access to recycling centers or recycling pickup, those materials will never make it back to a Materials Recovery Facility (MRF) for a chance at a second (or third or fourth…) life. That’s why we’re a proud member and supporting funder of the Polypropylene Recycling Coalition, a group of industry stakeholders working together to increase access to residential PP recycling. As of June 2024, the Coalition has provided $14.5 million in grants  to 58 recycling facilities in the U.S. to support new and improved PP sorting and has recovered 57 million new pounds of PP annually for processing.

Requirement #3: Recycling Engagement

Access is step one for households and participation is step two—an uphill battle to influence the daily actions of millions of households. Considering that just 43% of American households participate in recycling¹, there’s work to be done. Insert The Recycling Partnership’s Center for Sustainable Behavior and Impact, a hub fueled by data and research that identifies people-focused solutions to increasing residential recycling in the U.S., Milliken & Company Charitable Foundation is a proud co-founder of the center.

Requirement #4: Process and Sortation

Once materials have moved into an MRF, current sorting processes require huge amounts of manual labor and time. Right now, it is estimated that a MRF can sort and process about 87% of the recyclable material it receives¹. One potential solution to alleviating the tediousness of sorting and making it easier to scale, is with infrared sorting lines. The HolyGrail 2.0 Digital Watermark Project, which adds digital stamps to plastics, is leading the charge in this arena. Not only is Milliken a member of the projects, but our clarifiers have been used to help expand the use of digital watermarks to be used on clear plastics.

Another challenge is once materials have been processed through a MRF they are sent to be processed into recycled resin pellets. Some post-consumer recycled (PCR) plastics like polypropylene contain contaminants that make the recycled resin dark in color and have different property characteristics than virgin resin. Milliken has partnered with PureCycle Technologies to develop a process that takes PCR material and turns it into virgin-like resin, from a clarity and performance standpoint.

Requirement #5: End Markets

The final step in closing the recycling loop is the ability for recycled materials to be reused across a wide range of applications. As previously mentioned, one significant challenge is color. Partnering with PureCycle Technologies to develop a virgin-like clear resin will enable product designers and development teams to use post-consumer recycled polypropylene (rPP) in clear applications. By leveraging their unique processing technologies, our science expertise, and our additives, we’re working to enhance rPP resin and expand its use.

For example, our most recent collaboration with PureCycle Technologies and Churchill Container created a post-consumer recycled branded stadium cup that is made of 50% recycled content. Previously, only 10% recycled content was possible.

The traditional properties and characteristics of recycled resins like rPP make it a challenging material to use in applications with high technical specifications that require higher melt flow rates. In turn, the recycled material is typically used in applications like pallets, non-critical auto parts, or benches. Milliken performance additives like DeltaMax and viscosity modifiers can help maximize the melt flow rate enabling the rPP to be used in applications that require more stringent performance characteristics, like high-performance functional automotive parts.

Together with partners across the industry and product developments from our team of chemical experts, Milliken continues to strive toward making a positive impact for generations to come. For more information on the five requirements for effective plastic recycling, download The Recycling Partnership’s 2024 State of Recycling Report or contact us about how we can support you on your journey to circularity.

¹ Source: The Recycling Partnership, 2024 State of Recycling Report