Design for Recycled Content
By Dr Sameer Joshi . 16 Sep, 2019
By Dr Sameer Joshi . 16 Sep, 2019
Creating more sustainable packaging requires a multifaceted strategy to address an array of environmental considerations across the packaging life cycle. A key element of any sustainable packaging strategy is to ensure materials are effectively recovered at the end of their useful life to provide new inputs for industrial or biological cycles.
Recycling is the most prevalent recovery pathway for packaging, and in order to ensure that packaging is effectively recycled, the packaging community must engage on two critical fronts: designing packaging in such a way that it flows optimally through the recycling system, and supporting end markets for the recycled content created by that system.
In designing for recyclability, a package should be designed to flow smoothly through the entire recycling system. This means:
• It is accepted in the recycling collection receptacles available to end users.
• Waste haulers will collect and transport it.
• A material recovery facility (MRF) will sort it properly, if it is collected in a mix of materials.
• Reprocessors will turn it into valuable feed stocks used in the manufacture of new materials.
• End markets will purchase and use those new materials.
Designing recyclable packaging is critical to creating a supply of recycled materials.
However, for the recycling system to be robust and healthy, the practice of designing for recyclability must be accompanied by a practice of providing market demand for recycled content. Packaging producers play a key role in providing market demand by using recycled content in new packaging, “pulling” the recycling system in such a way that matches the “push” of designing for recyclability. Packaging isn’t the only end market for recycled content — recycled content can be used in the manufacture of new durable goods, nondurable goods, and materials for the built environment. While these open loop applications are critical, the demand created when new packaging is made with recycled content from old packaging is major component of the overall landscape of demand for recycled content and it directly applies the concept of circularity to packaging. This “take what you make” attitude helps transform the dialogue from recycling as an end in itself, to seeing recycling as a source of feedstock for new resources to be reused and given new lives.
Once packaging is collected, sorted, and reprocessed, circularity is only complete upon the use of that recycled material in the manufacture of a new product or packaging product or packaging.
General guidance for using recycled plastics
Each type of recycled plastic carries its own set of characteristics and considerations, which are covered in detail in other sections. However, there are some common themes that are broadly applicable:
The common assumptions surrounding recycled plastics should be challenged. There are many common misperceptions related to recycled plastics, including safety and cleanliness, consumer acceptance and understanding, dramatic losses of performance and aesthetic qualities, and lack of return on investment on the price premium associated with many recycled plastics. While many assumptions may be grounded in a kernel of truth, the level of mistrust surrounding recycled plastics is undue and in many cases, outdated. When presented with these types of descriptions of recycled content, asking for data or examples can be useful to understand whether or not the concerns are valid.
Experimentation and incremental increases are important strategies for using recycled content. Instead of approaching suppliers with a request for a specific percentage of recycled content, brands should aim to incorporate as much as possible while balancing trade-offs around performance, aesthetics, and cost. After taking a first step to introduce a small percentage of recycled content, experimentation should be used to determine the optimal level. This stair-stepping approach is also preferential to suppliers as they navigate the learning curve, allowing them to get the processes under control and make needed adjustments.
Key initiatives for building demand for recycled plastics:
• The Association of Plastic Recyclers’ (APR) Recycling Demand Champions program gathers industry commitments to increase use of recycled plastics, including use of recycled plastics in “Work In Process” (WIP) items such as crates, pallets, totes, drums and trash cans. These WIP items represent opportunities for use of lower grade recycled content that is more challenging to incorporate into consumer-facing packaging. . In the program’s first year, it increased demand for recycled plastics by nearly 7 million pounds.
• Every year, 8 million metric tons of plastic ends up in our oceans, and that figure could increase by tenfold over the next 10 years if actions are not taken. The majority of this, referred to as “ocean bound” plastics, comes from mismanaged waste from within 30 miles of a waterway or coast. Plastic found in the ocean and plastic bound for the ocean (on beaches or near waterways) has become an environmental poster child for the need to improve recycling systems and end markets for plastics. Some suppliers and brand owners have committed to sourcing ocean-bound plastic for reuse in their products and packaging as recycled content.
• Envision Plastics has committed to recycling 10 million pounds of ocean bound plastic over two years. To date, Envision Plastics has recycled five million pounds of HDPE, working with coastal organizations to collect packaging waste before it enters our waterways and shipping it to Envision Plastics’ plants where it is processed using its patented Deodorized Resin™ technology to clean and remove odors. Envision Plastics has had numerous partners use its OceanBound Plastic in consumer products and packaging. Earlier this year, ViTA debuted a hair care line using the first bottle made from 100 percent OceanBound Plastic.
• High quality recycled plastics often come with a price premium compared to their virgin counterparts. Prices fluctuate greatly and some recycled plastics — particularly those with suboptimal technical and aesthetic characteristics — can be supplied at a cost advantage. It is also important to consider that the use of recycled plastics may introduce added processing costs, especially when there are stringent specifications for performance and aesthetics that must be met. Companies that excel in using recycled content consider any added costs as an investment to upgrade their packaging, finding justification within the robust business case for using recycled content.
• A lack of long term contracts in material procurement can lead to price volatility and inconsistencies for recycled plastics, which creates market uncertainty and discourages investment. Strategic partnerships that increase the length of contracts between MRFs, recycled plastic recyclers, converters, and brand owners can be used to negotiate stable, lower prices on recycled content. This strategy has been successfully used in other commodity markets where long-term contracts specify payment of a fixed margin above the cost of production and all parties involved benefit from predictable pricing. Long term contracts can also help create demand stability for recycled plastics that in turn helps encourage investment.
Processing of recycled plastics
Adding recycled plastic to existing manufacturing processes isn’t always straightforward. Recycled resins don’t always act like virgin resins. The melt flow rate, an important indicator of the behavior of plastic in converting processes, can differ between virgin and recycled batches of the same polymer type, which introduces unwanted complexity. Even high quality recycled plastics can display inconsistent flow behavior, which is generally attributed to contamination within the recycled feedstocks. Investment in new or upgraded processing technologies and adjustments to equipment is a necessary and worthwhile investment to meet growing demand for recycled content.
“As conversion technologies improve, like with blending or quality processes, we will be able to use more and more recycled content and still meet the demands of the end users.” – Plastics Converter
“Manufacturing challenges with recycled content aren’t insurmountable, so we have to overcome challenges. But there can be challenges with running higher recycled content on a manufacturing line. We have to prioritize the time that is spent to qualify materials. Since we run high volume, high speed lines, if the recycled content lends itself to a defect on that line, then we may have shut downs on the line — and that’s a problem. So what we do is a lot of quality assurance and work up front to qualify and adjust our systems to accommodate that variability. That takes time and resources, so if making recycled content a reality is a priority for the business, there needs to be direction [from leadership] to the manufacturing team.” – Brand Owner
Performance of recycled plastics
Virgin plastic and recycled plastic rarely perform the exact same way. Contamination from other plastics in the recycled feedstock is the chief influencer, but colorants and additives in plastic packaging can also act as contaminants in recycled plastics. This can result in differences in a recycled plastic’s performance, including characteristics that affect sealing or structural integrity. However, there are solutions available to help manage many of the performance differences between recycled and virgin plastics.
There are tools to assess the performance of recycled plastics. There are well-established technologies that evaluate the quality of recycled plastics using physical, chemical or other tests. One of the most effective methods to check the quality of a recycled plastic involves running a small batch of extrusion blown-film. In a film format, the material can be checked for stability, bubbles, gels, color, odor, strength and other quality measurements. Any poor-quality material can be discarded or blended with a better performing material, depending on the end use application.
Techniques exist to improve performance of recycled plastics, including resin compounding, blending of various grades of a resin and introduction of performance additives. Performance additives include but are not limited to: antioxidants, UV absorbers, anti-block agents, colorants, fillers, and impact modifiers. These additives can increase performance and reduce defects like gels, brittleness, and odors. Some of these technologies are well-known in polymer engineering yet have not been widely adopted when using recycled plastics.
Featured innovation: Water-based heat sealants
Water-based heat sealants may alleviate issues related to heat sealing recycled plastics, a common problem due to the different melting points of recycled resins. These products are beginning to enter the market and can be explored as a way to increase the use of recycled plastics while minimizing performance challenges.
Aesthetics of recycled plastics
Color consistency and color matching are common challenges in using recycled plastic, since brands tend to implement very stringent color requirements for packaging. Unlike virgin plastics, which initially do not contain pigments, recycled plastics are derived from mixtures of materials that may contain a wide range of pigmentation. Brands interested in using recycled plastics must manage their expectations and commit to finding ways to work with the color variations present in recycled resins.
White or lightly colored recycled plastics may take on an off-white color. Clear recycled plastics may take on a somewhat yellowed appearance due to the reheating process, or a cloudy appearance due to contamination in the recycled feedstock. Natural, white or lightly colored recycled plastics can be adjusted by adding colorants to match brand colors, however, their new color may appear less vibrant than virgin material colored with the same colorant. Mixed-color streams of recovered plastics can typically only be recycled into dark, opaque colors.
“Typically, recycled materials are darker, grayer, or have some tint to them and that tint is not always consistent from batch to batch.” – Plastics Recycler
While these challenges are more pronounced with higher levels of recycled content, there are numerous examples of plastic packaging containing upwards of 30% recycled content with no or negligible aesthetic deficiencies. That percentage can be considered a general threshold above which aesthetic challenges should be expected to be more noticeable. While transparency may be critical for some applications, it is also important to note that the use of opaque plastic packaging allows for higher percentages of recycled content with fewer color challenges.
Progressive brands accept color variations that consumers can see, setting expectations with marketing departments and communicating variations through consumer messaging. This is easiest to implement in a new product line, a new brand, or a rebranding, in which alignment of expectations and strategy may be performed at the start. If the entire organization is aligned around recycled content, then discussions on color and modifying specifications become easier.
“Other design strategies to navigate these variations include using recycled content in applications and products where color is not of such high importance, such as trash bags, inner layers of multi-layer rigid containers, or other areas the consumer does not see, like applications in which the material is hidden behind a label. Concerns about color matching across products and units are more relevant for packaging on retail shelves than for online retail, and so online products may be an easy area to initiate higher levels of recycled content. Additives, such as specially formulated brighteners or clarifiers, can counteract the cloudy appearance typical of recycled resin.
Food contact for recycled plastics
Despite common misperceptions and skepticism, many recycled plastics meet the required quality for food, beverage and pharmaceutical applications. Most plastic recyclers providing recycled plastic for food-grade packaging applications have successfully petitioned for a “letter of no objection” (LNO) from the FDA, which provides assurance that the recycled plastic is safe for food-grade applications. It is important to note that the FDA does not test the recycled resin, and it is therefore up to individual recyclers to ensure their feedstocks and processes will consistently produce food-grade resins. There are mechanisms comparable to the FDA LNO in other countries.
Some producers of recycled plastic for food-grade applications restrict their feedstocks to post-commercial or post-industrial plastics that were previously designated as food-grade. Any added colorant must be individually compliant with FDA requirements, so clear plastic is commonly used for recycled food-grade resins since it is easiest to add a colorant that is known to be compliant to a clear recycled plastic.
Another approach to including recycled plastic in food packaging is to limit the use of recycled plastic to the inner layer(s) of a multi-layered construction, with an innermost virgin layer acting as an effective functional barrier. However, it may be necessary to demonstrate that the barrier will protect foods or drugs from unwanted migration.
Unfortunately, skepticism and misperceptions around the safety of recycled plastics for food and drug applications are common. Changing minds internally about the safety of food contact recycled content may be a hurdle, but it is important to gather support from within the organization for recycled plastic. Sharing information with others about the FDA’s process for issuing LNOs and the process used by suppliers to ensure food contact safety may be helpful.
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