Hi, hope you are all doing well…. Today’s blog is all about the adhesives and the way in which the improved formulas can help reduce the effects of toxic fumes on fire fighters….

The adhesives used in manufactured lumber have evolved and become more sophisticated since plywood was first introduced over a century ago. At that time, there were no consensus standards on the raw materials used, the performance of the adhesives used in assembly of the plywood, or the performance of the plywood when exposed to moisture or fire.

In 1947, a heat performance test was added to the then CS45 standard to evaluate adhesive bond resistance to fire and has been part of all standards revisions since. This requirement applies to all adhesive types used in manufactured lumber products and ensures that the adhesives do not lose their bond strength during fires. Interior- grade adhesives did not reliably meet the performance test and were phased out of production.

The adhesives used in exterior and structural plywood manufactured according to the standard since 1947 are thermosets. This means that once they are cured with heat, they have a permanent shape. They will not melt when exposed to heat or flame, although they can char and burn. The adhesive manufacturers state that when cured, the adhesives have ignition temperatures and burning characteristics similar to the wood that they bond.

As a result of the concern for the health effects of the formaldehyde and other toxic or irritating vapors that can be released from the adhesives used in manufactured wood products chemists are now revisiting the soy bean and have developed an interior grade of soy-based adhesive that uses no formaldehyde and whose performance surpasses that of the soy-based adhesives from the past. Chemists are hoping that future soy-based adhesives will replace the formaldehyde-based adhesives presently in use for interior and exterior grades of manufactured lumber.

……….. ‘Til the next time Greg