Recycling is becoming more popular as a way of both reducing the amount of waste we send to landfill and of conserving valuable or scarce resources. The second of these advantages could turn out to be the most important – many natural resources are limited, and when we’ve used them they’re gone forever. Recycling can make a huge difference to availability by making new products out of old ones instead of freshly extracted raw materials. Even renewable resources come at a price – land used for growing pulp trees might be more valuable for grazing livestock, if paper can be produced from recycled pulp instead.
It’s important to remember that recycling isn’t a magic bullet though. It can make a big impact, but one problem is that recycled materials often aren’t the same quality as the original waste was. This means that what’s recovered might not be suitable for making the same kinds of products, or might only be capable of recycling a limited number of times before it’s no longer usable. Improved technology is reducing this issue in some areas but it’s still very real. It even has a name – “downcycling”.
A classic example of downcycling is what happens to many plastics. Most drinks bottles are made from PET and these are commonly recycled – in fact they’re a main target of recycling campaigns in many countries, including Germany where the deposit is much higher than for glass bottles. So far it’s not possible to reprocess them into new drinks bottles though. Instead they’re used to make lower grade containers or fiber for polyester fabrics. There are multiple reasons for this, the main one being impurities from labels, adhesives and even bottle caps. PET also has a limited number of reprocessing cycles, as after multiple uses the polymers begin to break down into shorter ones that lack strength.
PVC is another commonly recycled plastic that is usually downcycled into lower quality material because of impurities, but it’s also an example of how improving technology can improve recovery rates. The new Vinyloop process reverses the procedure and instead of trying to remove all impurities from the PVC, a specialized solvent is used to dissolve the PVC and leave the impurities behind. The PVC is then removed from solution by a steam process and can be remanufactured into high quality products. The energy needed is also 46 percent lower than for freshly manufactured PVC. Vinyloop was used on a large scale after the London Olympics.
Paper is also commonly downcycled; packaging material, paperback books, toilet paper and cheap writing pads are often made from recycled material while higher quality paper is made from fresh pulp. There’s a limit of about seven cycles for paper as the fibers that give it its strength slowly break down. It can be used as packing material for several more cycles and improved processing techniques may extend the life of the fibers.
Even the current imperfect recycling methods are extremely valuable; downcycled material still reduces the demand for resources. It’s not a full solution to dwindling reserves of raw materials though, and it’s important to keep improving the technology as well as trying to sue things more carefully.