You have, no doubt, seen the bins inside many stores where used shopping bags can be deposited for recycling. Have you ever wondered what becomes of them? Unlike some may think, these bags are generally not made into new bags. In fact most of them are made into composite lumber.
There are two kinds of “plastic” lumber.
- Composite lumber is made by heating powdered or pelletized virgin and recycled plastics including HDPE, PVC, PP, ABS, PS and PLA into a thermoplastic resin and mixing this with wood flour (very fine saw-dust) to a dough-like consistency. This can then be extruded or injection molded to the desired shape. Additives such as colorants, coupling agents, stabilizers, blowing agents, reinforcing agents, foaming agents, and lubricants can help tailor the end product to the application.
- Plastic lumber (such as Polywood®) is made in a similar fashion, except it is composed entirely of plastics.
The product can be molded into a variety of shapes, even extruded as a hollow post. The molding process often includes stamping a wood-grain pattern onto one or more faces, depending on the product’s intended use.
Using Plastic Lumber
Plastic lumber behaves much like wood: workers can shape it using conventional woodworking tools. However, care must be taken not to remove or damage the wood-grained faces (if any).
Both composite lumber and plastic lumber are more flammable than natural wood because of the volatile chemicals in their make-up. But both are also completely recyclable. They just grind it up and make it into new lumber.
Neither plastic lumber or composite lumber are completely maintenance free, but both offer greatly reduced maintenance over wood in applications like decks, fencing, and outdoor furniture. Most composite lumber can be stained or painted, most plastic lumber cannot. Both types are waterproof and resist all types of rot and mold, although they are not as rigid as wood and may deform in extremely hot weather.
Making a Bazillion New Bags
You might wonder, since most of these bags are NOT used to make new shopping bags, are we using up natural resources, especially expensive imported oil, to make the bazillion new shopping bags a year we use up? Yes and no. About 85 percent of the plastic bags used in the United States are American-made and come from natural gas, not foreign oil. Natural gas is a non-renewable resource, but at least it is domestically produced.
Paper or Plastic?
Wouldn’t it be better to use paper bags? Though commonly debated, many are surprised to find out that compared to paper; plastic shopping bags can be a resource-efficient choice. Plastic grocery bags require 70 percent less energy to manufacture than paper bags, and produce half the amount of greenhouse gas emissions in the process.
If the bags are recycled and used to make building materials that reduce the need to cut timber, nothing is lost. Of course, if the bags end up in the landfill, not only are the resources wasted but the land is polluted with materials that take a very long time to break down.
If you’re still hesitant, there is a third choice: reusable shopping bags. Some are made of plastic cloth (which often IS made from recycled shopping bags), some of canvas. Both can be reused hundreds of times and nothing at all goes into the trash. Just keep them in your car, take them in with you and just say “No thanks, I have my own.”