Block Solutions CEO Sanna Silfverberg explained in an email interview that her firm collects its plastic feedstock from "normal household waste or other sources with safe and traceable origins." The firm's recycling partners "provide us with proof of origin for the material," she said. "This is really to make sure that the blocks are safe to build with."
The resulting biocomposites contain 50 to 70 percent plastic, and the firm currently does not incorporate any additives into the compounds. She said the company can use waste PP, polyethylene (PE) and PET, and continues to investigate other resins.
Outside of Finland, Block Solutions says it expects to use alternate fibers for its product, such as bamboo, sugarcane, acacia and rice husk. "The carbon footprint of our product is close to zero," the company claims.
The Eco-Blocks are joined together using a rubber hammer, and can be modified with normal woodworking machines, for example, to cut out holes for electrical sockets. "A 30-square-meter building can be built in 2.5 hours by two persons without any professional experience in construction," the company says on its website.
"PP is the most suitable resin for processing and gives good quality finishing and strength," Silfverberg noted. "PE is also very close in performance to PP, but a little softer. PET has a slight disadvantage with the weight and processing, but it is working nicely in the production."