PaperStone: Panels Made with Cashew-Nut-Hull Resin

Cashew nuts grow as appendages on the ends of cashew fruits, which are the size of apples. The nuts are encased in a leathery skin that is saturated with toxic oils, specifically cardol and anacardic acid. (An acquaintance bit into a raw cashew nut right off a tree and was unable to taste food for the next three days!) Cashew-nut shell liquid (CSNL) has a long history of industrial uses, including in typewriter rolls and brake linings. Since the 1950s, researchers have been experimenting with ways to use it as a binder in composite wood products. The biggest barriers to more widespread use of CSNL have been the low cost of petroleum and the natural variation in the chemistry of the oils.