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The Break-down on Biodegradable PLA's

By Than Hansen | Published: April 08, 2008

Overview
Many designers and manufacturers are asking themselves what the emergence of PLA (Polylactic Acid) and other so-called bioplastics really represents in terms of creating viable alternatives to petroleum-based plastics. From packaging, graphic, product and furniture design, to interior design and architecture, industries are busy imagining the many uses and potential applications for this biodegradable plastic.

With the onset of PLA, comes both great potential as well as some very significant questions and challenges that must be considered. Investors and the media have latched on to the concept as a way to keep in line with buying habits and the current lifecycle of products. However, countries such as the United States do not yet have a strong network of recycling facilities to enable a closed loop system, which is in short, a system whereby materials used in products that we dispose of everyday, may be "upcycled" into things of equal or greater value (a philosophy coined and explained quite articulately by William McDonough and Michael Braungart in their book, "Cradle to Cradle").

PLA Defined
The material called Polylactic Acid (PLA) is derived from a number of plant-based sources, including corn, wheat, sugar cane, and potentially even potatoes. The production process involves the separation of starch from one of these sources, transforming it into a sugar, and fermenting it to form lactic acid. This is then converted into a lactide, and crystallized to form the PLA polymer, which may then be modified in various ways depending on the particular product for which it is intended.

Common Uses
- Consumer electronics casings
- Automotive interiors
- Clothing
- Cosmetics packaging
- Carpet fiber/carpet backing
- Food containers
- Utensils

Challenges
Waste is a common symptom of countries with abundant resources, as there is no immediate desire or urgency to conserve. In the history of the U.S., recycling has often been seen as an expensive process, and has conjured both political and economic fear that implementing the process on a wide scale would cause an outflow of jobs. As a result, companies today are seeking a solution that does not require such a large infrastructure, (the materials will take care of themselves at the end of their lifecycle) and will keep jobs steady (currently, Iowa state officials are pushing hard to back corn for uses other than for food because it is their main crop, and to help farmers maintain steady work and higher wages).

There are growing concerns that the rush for this alternative to petroleum-based plastics is leading to a depletion of the grain as a food stock for dependent countries, as well as dramatic inflation in commodity prices (witnessed over the past year or so). Genetically modified corn is often used early in PLA's production stream, and many people are concerned that there are a number of unanswered questions regarding the effects of genetically modified crops on individual health and the environment. Many PLA-producing companies are aware of both of these drawbacks, and are actively seeking alternatives to using virgin corn kernels, such as corn stalks, as well as offering non-GMO alternatives when possible. Corn is a very resource-intensive ingredient in PLA because it requires a great deal of water to grow, as well as nitrogen and petroleum-based fertilizers and pesticides which have long term negative effects on soil quality. Corn-based Ethanol is fast becoming an alternative to gasoline, which is also accelerating the run up in commodity prices, in spite of cellulose (from switchgrass, trees, etc) being a far less resource intensive source for the fuel, as well as potentially PLA itself. For greater surface strength and heat resistance (in consumer electronics casings), additives or strengtheners must be used along with PLA, which in turn make it potentially more difficult (or impossible) to separate the material components out before eventual composting at end of life. Due to the controlled environment required to break down the plastic, PLA products cannot be recycled alongside standard plastics (PP, PET, HDPE), as they would contaminate the waste stream, so a commercial composting facility must be used in order to achieve the desired results.

Alternatives
- Arboform - Lignin/tree pulp-based moldable thermo-plastic
- Bagasse - Fibrous by-product from sugar cane (used by Staples for paper and folders)
- Palm Fiber - By-product from palm oil production
- AgroResin - Agricultural biomass
- Reed Fiber - River reed-based material
- PlasTerra - Combination of bioresins
- Cereplast Compostables and Hybrid Resins - Agro-base bio resin
- Recycled plastic (Recycline's Preserve line, Patagonia clothing)

Conclusions
In the United States and China, the social challenge of over consumption and an attachment to "disposable" goods is something that must be faced. As designers, one immediate way to conceive and create in a more sustainable way is to consider "electronic convergence", for example. Most iPhone users use about half as much paper as they did before, because they are now able to access the Internet, email, contacts, notes, street maps (the list goes on), with the aid of one easy-to-use device. There is no need to buy a separate GPS system, bring along the laptop, or even start up your desktop PC to get a stream of sophisticated information. With the iPhone, Apple has created a product that is valuable, and not simply a coveted luxury item like the $800 Prada phone by LG, or a $4000 (and up) Vertu. After using and experiencing the phone for some length of time, one can easily realize that it continues to exceed initial expectations, and is well worth the initial cost, thus moving it away from any sense that it is "disposable".

PLA plastics are not perfect and one of the best ways to think of material use, reuse, and disposal is simply to think about "better design". To conceive for longevity, repurposing, and reclamation, rather than thinking in terms of how brief a product's life will be. A large challenge that the United States faces is its history and comfort with planned obsolescence within today's consumer culture and current infrastructure. A hard sell for many eco savvy designers, there are few products on the market that leverage their biodegradability through design and experience. To make an effective case for PLA, we must develop it from non-food based sources for its production, but also, reevaluate our notion of how long products should last and their long term impact at end of life.

Addressing the health issue of using a recycled PVC plastic is a much more manageable problem to solve, when compared to shifting to a completely new infrastructure that is already being stressed for food production. In addition, the great thing about "reusable trash" is that it is all around us! There are dumps and landfills throughout the United States, yet no one has begun to tap into this resource with machines that can sort and recycle without using any new petroleum. For years, in Germany, Volkswagen has been required to "buy-back" their cars, forcing them to ensure that they are easy to disassemble, and that the materials can be reused. With the astonishing trend in investing in alternative energy and "green" companies in the U.S., we hope to see more growth in the "recycling" industry as a whole. In fact, it is difficult to imagine that even today, there are a number of U.S. states that still do not have a mandate in place for recycling. However, some companies such as Nokia, Herman Miller and HP are even taking matters into their own hands and opening up their own recycling plants in the U.S. They are finding it not only more sustainable but also quite profitable.

Instead of shifting over to another material, and having to create a new infrastructure, why not use what we already have? Countries like Sweden recycle 110% of what they produce. They actually make a profit on importing other countries' "trash" for their own recycling. With all of the waste simply sitting in landfills in the United States, businesses are finally beginning to use resources in our "own backyards." There are plenty of materials made using 100% recycled content already on the market, and as long as they stay in the production loop, they are great alternatives to virgin material.

In short, we think biodegradable plastics such as PLA are great if they can actually be composted at the end of their lifecycle. The products or building they are being used to create, MUST have a NEED for biodegradability. It takes a large amount of energy, borrowed resources and a new infrastructure to produce, distribute and compost these types of bio-plastics, and they will remain in landfills equally as long as petroleum plastics if not properly disposed of (note, we say "dispose" as they are excluding themselves from any chance of being involved in a closed-loop system). They are a tough sell as a miracle alternative, and there is already a growing infrastructure based on recycling being formed today. Upcycling existing materials is by far the way to go. All the signs we have seen say stay away from the food supply that people and societies as a whole rely on. Countries need their corn crops for food which in turn supports their economy and sustains their people. They should not be used for plastics that are over-consumed through disposable products and cars that are driving on an infrastructure built 50 years ago and fueled by expending resources to create jobs.

Do you have comments about this article? Let us know at design@ecolect.net.

Resources
NatureWorks
Ingeo Fibers
Cereplast
Metabolix
Mirel
Hytrel
Plantic
PlasTerra
Arboform
Treeplast
Bioplastics Magazine
EcoWare Products
Agroresin
Traypak
Omnexus Plastics Editorial
Co-op America Plastics Article