CleanFiber turns mountains of used cardboard into low-energy home insulation

Walk through any neighborhood, and you're likely to see dumpsters and recycling bins jam-packed with cardboard boxes — the corrugated remains of our passion for online shopping.* While recycling rates for cardboard are much higher than for plastic, there's still a massive amount of material that needs to be processed.

A Buffalo-based scale-up found a solution: shredding boxes to create insulation for buildings. CleanFiber produces fluffy cellulose insulation that can be blown into the hollow spaces between walls and under roofs and floors. Traditionally, cellulose insulation is made by grinding recycled newspapers. With newspaper circulation down, CleanFiber's founders turned to a readily available alternative: corrugated cardboard. The company's patented technique makes for loosefill insulation that creates less dust than the newspaper version. It also takes less energy to produce than foam or fiberglass insulation, making for lower carbon emissions.

CleanFiber launched its product commercially in 2020 and just closed a USD 10 million investment round.

* Intriguingly, the e-commerce boom hasn't increased cardboard production, at least not in the US.