Scrap foam disposal: what you need to know
by Duncan Geddes
The disposal of scrap foam is becoming an increasingly important subject for both manufacturers and converters of polyurethane foam. Foam is inherently a volumetric but light-weight material, so what methods are there to dispose of scrap foam? And is the foam recycling industry really equipped to handle the sheer volume of scrap that’s being produced?
Where does scrap foam come from?
From the day that the first ever block of polyurethane foam was made and converted into cut parts, the question of what to do with the remaining scrap has been on the minds of foam industry experts and professionals.
Scrap foam – or foam offcuts – are a natural byproduct of the foam production process. Production efficiency dictates that the foam convertor aims to produce as many components as possible from a block of raw material, therefore minimising the amount of scrap foam. Even so, almost every single block of foam that gets converted produces at least a small amount of scrap material.
Flexible polyurethane foams were originally developed during World War II for use as aircraft coatings. However, production was small, and it wasn’t until the 1950s that chemical giants such as DuPont, BASF and Dow Chemicals started developing toluene diisocyanate and polyurethane polyols, which were required to manufacture commercial-scale volumes of polyurethane foam.
During the last 60 years, it’s estimated that this now totals millions of tonnes of scrap polyurethane foam. But where has that foam gone? Perhaps even more sobering is that the same question can be applied to polyethylene and other closed-cell materials, the production of which also leads to tonnes of wastage and scrap every year.
Methods to dispose of scrap foam
The options for scrap foam disposal are entirely dependent on the density and quality of the material that’s being produced. All too often, burning scrap foam is assumed to be the default method to get rid of waste.
Flexible polyurethane foam can be burnt fairly easily, but this process generates toxic fumes that are hazardous to both the individuals involved in the process and the environment as a whole. These concerns have led foam manufacturers and converters to search for new ways to manage the high volume of scrap foam that’s being produced each year.
Can scrap foam be recycled?
Finding a new method is far better, and fits in with the modern-day aspirations of recycling all our scrap materials; but to date, the only volumetric use for scrap polyurethane foam is reconstituted foam, otherwise known as chipfoam.
This is basically the process of granulating foam into small pieces of a few millimetres in size, re-bonding them into a large block form, which is then compressed to various densities. Applications for chipfoam include packaging, floor mats, sound absorption panels, but the main use is as a carpet underlay.
Manufacturers of carpet underlay are, therefore, driven by the need for their respective plants to obtain as much scrap foam as possible. Over the years, these plants have established efficient methods of collecting scrap materials from foam converters around the world and shipping it back to their underlay factories. This dramatically reduces the volume of scrap polyurethane left to be disposed of via other methods.
Scrap foam is still sent to landfill
Although the chipfoam production process uses a large amount of scrap foam, it does generally require ‘virgin’ material. This means that if the foam has been laminated to fabric or adhesive tape, it’s typically rendered unusable for carpet underlay.
The same issues apply to closed-cell polyethylene foam. Again, scrap foam is collected from convertors and taken back to a manufacturing plant where it’s granulated. This is then used to produce items such as floor mats and playground mats. However, scrap polyethylene foam that has been subjected to additional conversion processes can’t be reprocessed and must also be disposed of using alternative methods.
So, what happens to all the scrap foam that can’t be recycled? There’s also the polyurethane dust, block skins and other byproducts of the conversion process to consider. We know that burning it is hazardous so, in reality, landfill is still the only remaining option.
Two species of the Ecuadorian fungus Pestalotiopsis are capable of bio-degrading polyurethane in aerobic and anaerobic conditions, such as those which are found at the bottom of landfills. However, this process takes hundreds of years and studies to date have not determined how to speed up degradation methods.
What’s next for the industry?
The time it takes for scrap foam to degrade creates a huge challenge for the foam industry and also for those consumers who care about their environment. We see and encounter foam every day, and our reliance on this highly versatile material makes it unlikely that production rates will slow anytime soon.
Polyurethane foams are used in a vast range of applications, including the automotive and retail industries. Therefore, there is a growing need to develop a new product for any scrap that the foam conversion process leads to. The kind of chipfoam that gets used in carpet underlay has been a successful start, but the next step is yet to be established.
At TFS, we have a commitment to minimising the environmental impact of the foam conversion process. We seek to send as little scrap foam to landfill as possible and are strong supporters of efforts to further develop the foam recycling process.
We work closely with our clients to design new and exciting ways to get the most from every inch of foam that’s produced. As new developments to the foam disposal process emerge, we’re looking forward to finding even more innovative ways to repurpose scrap foam and reduce the amount of waste within the industry. To discuss how recycled foam products could have a positive impact on your business, get in touch with our team.
Thanks for reading. I hope you found the article interesting and useful. If you did, why not share it with your LinkedIn network?
If you are developing a product that uses foam, you can always give us a call to help you with any of the aspects addressed in this article. Find out more about Technical Foam Services here and you can follow me on LinkedIn for more articles like this.