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The burden of bioplastics



By Calvin Frost, Contributing Editor



Published November 29, 2012
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Alexander Watson Associates (AWA) has just completed its first edition of the Pressure Sensitive Label Waste Management Report. It’s a summary of where waste is generated in our supply chain, the complexity of logistics and packaging, and the difficulty of developing a comprehensive, “one size fits all,” solution; very daunting, to say the least. The report touches one aspect that I have written about in colloquial terms but never referred to in a more formal fashion: EPR, Extended Producer Responsibility. While the broad implications of EPR are a long way off, we are beginning to see more advocacy for making manufacturers responsible for what they produce, from cradle to cradle. As Scott Mouw, recycling director for the State of North Carolina says, “We can’t get to the top of the mountain staying on the road we’re on now.” I think he’s right and I have urged in countless columns that the company that manufactures take responsibility for solving byproduct generation. Hence, the OEM is responsible for a solution for the matrix that is generated by the converter. And, the converter is responsible for providing a solution for spent liner that is generated by the end user. And, so on, through the value chain. We are seeing a groundswell that supports EPR from organizations like the Sustainable Packaging Coalition, the American Institute for Packaging and the Environment, the Packaging Association of Canada, and others. So take heed as change is in the wind.

Extender Producer Responsibility is a great introduction to what I call the “burden of bioplastics.” The folks who create these friendly materials have actually created a very complex end-of-life problem. Let me explain.

There is no question that bioplastics will grow substantially during the next ten or twenty years. Manufacturers of these materials are capitalizing on their appeal to consumers, retailers and the entire packaging industry. While this genre of material is environmentally friendly, the end-of-life scenario causes concern for conventional recyclers and composters because of bioplastics’ varied end-of-life requirements. Bioplastics are derived from renewable feedstocks like vegetable fats and oils and cornstarch. And some of the chemistries have the added benefit of being able to decompose in natural aerobic and anaerobic conditions. Keep in mind that this category of plastic accounts for less than one percent of the 230 million tons of plastic produced annually.  Jim Lunt of Jim Lunt & Associates estimates that the bioplastics market is less than half of the one percent. However, with the anticipated growth of bioplastics, we’re seeing a range of issues compounded. For example, polylactic acid (PLA) can be composted, but not recycled. Other bioplastics are chemically identical to conventional plastics and are recyclable but not compostable. You can imagine the issues when compostable materials end up in recycling streams or vice versa. The result is waste to landfill: a conundrum for sure. On the one hand we’ve created a friendly material; on the other hand, we’ve created a much more complicated solution for end-of-life scenarios. Therefore, it seems to me, the very idea and design of these materials fail to answer the Extended Producer Responsibility goal. Their developers have created something, but neglected to include a simple, efficient, end-of-life solution.

PLA is a rigid thermoform derived from lactic acid and is used in packaging. PLA was commercialized in 1997 through a joint venture by Dow Chemical and Cargill. Cargill eventually bought out Dow and renamed the company NatureWorks. As of this writing, the 140,000 tons per year plant in Nebraska (close to their feedstock, corn) is completely sold out and there is talk of a second facility to take advantage of product demand.

Cereplast is another manufacturer of plastic resins that contain PLA. Still, we can’t determine how much PLA ends up in the waste stream. It looks like polyethylene terephthalate (PET) and, of course, that’s part of the problem, because it doesn’t recycle like PET. Other bioplastics, polyhydroxy alkanoate (PhA) or polyhydroxy butyrak (PHB) are not clear and are much more easily separated with manual screening. Manual screening can remove some PLA during processing. But then it gets more difficult.  PLA and PET thermoforms look similar. PLA sinks in a float-sink separator just like PET, whereas high density polyethylene (HDPE) and polypropylene (PP) do not.  If the recycler is unable to remove PLA from his PET stream, he has a problem. PLA melts at the operating temperature of the PET dryers and this damages the dryers and they become difficult to use. Not only will PLA damage dryers but it distorts the final PET reclaimed resin. It puts a haze into the film and the brand owner will not accept a contaminated clam shell. While the contaminated thermoform is mechanically and physically within specification, it is defective cosmetically. (This represents a whole different can of worms: why must the brand owner sacrifice responsible end-of-life solutions for printing materials in favor of pure clear/clean presentation? Which is more important, marketing or environmental responsibility?)

The PLA recycling issues essentially escalate into economic issues. If a recycler finds PLA in a PET bale that he has paid for, he incurs extra costs to attempt to remove the PLA so that the PET retains its value. But the quantity of removed PLA is generally so small that the recycler can’t justify the cost for further sorting. He landfills the bale because he can’t risk losing a customer because of streaks of haze. So, a conundrum.

Of course, everything comes down to size of scale. Just like the use of Recycle Compatible Adhesives (RCA): if the industry would use more RCA technology, the price would drop. If we used more PLA we could justify setting up separate recycling streams. That’s what NatureWorks would like. Currently there are two commercial PLA recycling centers, one in Wisconsin and one in Belgium, that convert PLA back into lactic acid. Indeed, NatureWorks believes if they can grow PLA volume they can develop a recycling infrastructure. By capturing the stream of byproduct and turning it back into PLA, NatureWorks saves time, energy and expense of fermentation from corn.

Recyclers not only have a problem separating bioplastics from petro-based plastics but are challenged by compostable materials.  Bioplastic materials such as compostable trash can liners are regularly used in communities like San Francisco that are required to divert food waste for composting. People and businesses don’t like to use containers because they have to be cleaned. A compostable trash liner can hold food waste and be sent directly to a composting facility without fuss or muss. Enter the government who has told organizations that sell compost to farmers of USDA certified organic products that they should not allow any compostable bioplastics to be part of the feedstock for organic compost. In my view this is another example of Extender Producer Responsibility.  The manufacturer of compostable bioplastic trash liners must solve the issue of compatibility so the composting operation is not jeopardizing its product. Bioplastics, even those that have been proven non-toxic and compostable, are considered synthetic and are not listed as being a safe feedstock for organically grown products.

How do we sort through all of this? It is the early days and we are in the first and second generation of green chemistries. Bioplastics aren’t going to go away. Lunt & Associates predict that the market for these unique products will grow to $100 billion by 2020. That’s billion, not million.  What needs to occur at the same time is the development of recycling and composting infrastructures that will either recycle or consume and not cause contamination for traditional recyclers. This is the most important aspect of EPR in developing bioplastic products. Trust me, it will happen.
Another Letter from the Earth.



Calvin Frost is chairman of Channeled Resources Group, headquartered in Chicago, the parent company of Maratech International and GMC Coating. His email address is
cfrost@channeledresources.com.


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