Wood Plastic composite lumber Recyclability
Wood Plastic lumber End-of-Life Recyclability: A Facet of Sustainable Design
In order to make a significant long-term impact on reducing resource use and disposal, it is not only important that plastic lumber include recycled content, but also that the lumber product itself be recyclable at the end of its life. Otherwise the material will still eventually end up in an incinerator or landfill. Plastics use overall is increasing, while plastics recycling fails to keep pace with that growth. Plastic lumber could help close that gap – or it could just provide greenwash incentive for more plastic manufacturing and use.
Plastic lumber is currently largely made from first-use applications that are not environmentally sound, like packaging made from virgin plastic. Unless plastic lumber is itself truly, efficiently recyclable and thus can become part of a closed-loop system of plastic products being indefinitely recycled, a growing plastic lumber market could actually increase plastics production and waste volumes.
Some manufacturers claim that their plastic lumber products (including wood-plastic composite lumber) are recyclable. These claims cannot be easily tested at this time. Although most manufacturers claim that there are few technical barriers to recycling their product, the same could be said for most plastics in use today, or bottles or cans or paper, most of which goes unrecycled in the United States for the lack of infrastructure and the public policy to support it. Even if original manufacturers are able to recycle their products once they come out of service, experience shows that in the absence of legislation or a well-developed infrastructure, this is unlikely to happen.
While plastic lumber has been in use for the last 15 years, it is a durable product and little of it has yet to come out of service. Therefore, there is not enough experience with plastic lumber to determine whether or not it will be feasible to recycle after its service life. A number of plastic lumber manufacturers take back scraps from construction or installation and recycle this material back into their product lines. Some companies producing all-HDPE plastic lumber are even selling scraps to third-party recyclers. However, this is far different than recycling the product once it has reached the end of its service life.
Municipal recycling programs generally do not accept and recycle plastic lumber. However, private sector recycling at construction demolition and building sites is a growing trend. Successful construction material recovery efforts involve segregating materials by type such as wood, metal, bricks, and gypsum board. Few if any building products are sent back to original manufacturers. Thus it is likely that if plastic lumber is to be recycled efficiently after its service life, it will have to be marketable to multiple end users. Because of this, product composition assumes greater importance. One major factor that will likely impact the recovery of plastic lumber is its composition.