Various Kraft lignin binder formulations with phenolic resins were developed and tested in terms of application, curing requirements and product performance. The two most promising glues were selected and this report presents their evaluation as binder for laminated lumber. For the first time, a rapid method of curing lignin adhesives in laminated lumber was developed using the residual heat from pre-heated wood. The study has confirmed that rapid lamination of lumber using low cost lignin binder is possible. Further study for rapid methods of pre-heating the laminae and application of the binder is required. The development of a faster curing low cost binder would be the best improvement to the process.
The relationship of press closing time, strength properties and density profile of thick waferboard panels to mat moisture content was demonstrated in this study. Lower mat moisture contents were found to increase press clothing time but permit faster binder curing. When the distribution of mat moisture was higher in the face layers, shorter press times were achievable and a significant densification of the panel was observed.