Accelerated Tests for Deterioration of Adhesive Bonds in Plywood
SourceThis research is part of a long-range program to develop laboratory methods for predicting the service life of glued products. Eleven methods for speeding the deterioration of wood-to-wood bonds are compared, employing Douglas-fir plywood bonded with a range of adhesives from interior to exterior grade. The most rapid answers were provided by methods employing boiling in water and drying in hot air, while the slowest method used was continuous soaking in water at 72 F. A promising method for predicting bond service life explored in this research is to consider bond degradation as a chemical reaction-rate process. The results affirm the possibility of developing accelerated methods for predicting the service lives of glued products, but the validity of these hypotheses must be checked against wider ranges of species of wood and glues before they can be accepted without reservation.