Examples on display of commonly available wood boards as well as the new custom sawdust/paper fiber composite board as used in the exhibition.
From left to right: plywood, particle board, oriented strand board (OSB), medium density fiberboard (MDF), custom sawdust/paper fiber composite board. Audience was invited to lift boards off wall to see and feel the difference among the variety of boards.
Plywood is an engineered wood product made from thin layers of wood veneer that are glued together with adjacent layers having their wood grain at right angles to each other to form a composite material. Plywood for indoor use generally uses urea-formaldehyde glue, which has limited water resistance, while outdoor and marine-grade plywood are designed to withstand rot, and use a water resistant phenol-formaldehyde glue to prevent delamination and to retain strength in high humidity.
Particle board is an engineered wood product manufactured from wood chips, sawmill shavings, or even sawdust, and a synthetic resin or other suitable binder. It is cheaper, denser, and more uniform than conventional wood and plywood and is substituted for them when appearance and strength are less important than cost. Phenol-formaldehyde is typically used in external applications and involves various other chemicals — including wax, dyes, wetting agents, release agents — to make the final product. Once resin has been mixed with the particles, the liquid mixture is made into a sheet then compressed under high temperatures to harden the glue.
Oriented strand board (OSB) is an engineered wood product manufactured in wide mats from cross-oriented layers of thin, rectangular wooden strips compressed and bonded together with wax and resin adhesives. Placed in a thermal press to compress the strips and bond them by heat activation, panels are then cut from the mats into finished sizes. It has properties similar to plywood, but is more uniform and cheaper and has replaced plywood in many environments, especially the North American structural panel market.
Medium density fiberboard (MDF) is an engineered wood product formed by breaking down hardwood or softwood residuals into wood fibers, often in a defibrator, combining it with wax and a resin binder, and forming panels by applying high temperature and pressure. MDF is denser than plywood and can be used as a building material similar in application to plywood. Formaldehyde resins are commonly used to bind MDF together and testing has consistently revealed that MDF products emit urea-formaldehyde and other volatile organic compounds that pose health risks at sufficient concentrations, for at least several months after manufacture.
Custom sawdust/paper fiber composite board - When Christine Lee was a Resident Artist at the University of Wisconsin–Madison Art Department’s Wood Program in 2010, she worked with a supply of excess, post-industrial wood donated from a local millwork company. Being accountable for even more waste, Lee collected the sawdust she generated and worked with U.S. Department of Agriculture Forest Products Laboratory Research Engineer John F. Hunt to create these entirely biodegradable and recyclable boards. Made with just sawdust and recycled paper pulp fibers, Lee and Hunt used various forming processes without the use of resins or adhesives to create these boards. This is the exact material (in 1/4” and 1/2” thicknesses) that was given to the artists in the exhibition to work with.
By-product Becomes Product
February 6 – March 30, 2013
Intersection for the Arts
San Francisco, CA
Photo credit: Scott Chernis