Most foam is not degraded in naturally environment, resulting in extreme pollution. Meanwhile the disposal of scrap foam is becoming an increasingly important subject for both manufacturers and converters of any foam. Foam is inherently a volumetric but light-weight material, so what methods are there to dispose of scrap foam? How to solve the pollution from the original?
Where does scrap foam come from?
From the day that the first ever block of any foam was made and converted into cut parts, the question of what to do with the remaining scrap hasbeen on theminds 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 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 and melamine foam.
During the last 60 years, it’s estimated that this now totals millions of tons of scrap flexible foam. But where has that foam gone? Perhaps even more sobering is that the same question can be applied to polyethylene, melamine foam, and other closed-cell materials, the production of which also leads to tons 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 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 foam is reconstituted foam, otherwise known as chipfoam.
This is basically the process of granulating foam into small pieces of a few millimeters 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 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.