A report on the potential for reducing LVL pressing times using faster curing phenolic formulations. A possible strategy to reduce LVL pressing times is to use faster curing adhesives. Because phenolic adhesives are accepted for exterior structural applications in the CSA standards, different phenolic formulations were evaluated in this study. The advantage of adhesive technology compared to RF or steam-injection technology to reduce pressing times of LVL is the much easier implementation since no large capital items are required. The results show good potential for reducing LVL pressing times using faster curing phenolic formulations. Some of the phenolic formulations showed LVL pressing times could be reduced by more than half.
Experiments were conducted to evaluate steam-injection pressing of plywood using saturated and superheated steam conditions and three steam-injection times of 1, 2 and 3 minutes. The results showed faster pressing times were achieved with the lower steam-injection times of 1 and 2 minutes. All the panels prepared under a variety of steam conditions exhibited excellent bond quality and the average % wood failure was greater than 80% in all cases. Using steam-injection times of 1 and 2 minutes for both superheated and saturated steam conditions, the pressing time was reduced by over 30% compared to conventional platen heating. An economic analysis of return on investment for thick plywood products shows the pay-back period for retrofitting an existing plywood press for steam injection is less than 2 months.
