The only difference between these plywood samples is the direction of cracks in the wood, which obviously affected the adhesive-performance (right image) test results. Anti Rohumaa, Aalto University Snapshot: Cooperation with Finnish researchers results in new understanding of relationships between veneer processing, veneer properties, and product failure.

Summary:  Wood veneers are used widely in making plywood, engineered wood flooring, and furniture; however, little is known about how harvesting and processing it affect the quality of the veneer for wood bonding. A joint study between the the Forest Service's Forest Products Laboratory and Aalto University in Finland revealed that the season of logging and the temperature of the log when veneers are peeled off have a significant impact on the surface quality of the veneer and the strength of the glue joints that attach it to another material. The study also showed the results in some standard adhesive performance tests are highly dependent on the size and orientation of veneer checks (cracks that form during peeling). Current tests are not evaluating the adhesive as intended and decisions are being made based on unreliable information. The research results also describe how to conduct the tests in a much more reliable way.	Princpal Investigator(s):   Frihart, Charles R.  Hunt, Christopher G. Research Location:  Aalto University, Otaniemi, Finland Forest Products Laboratory, Madison, Wisconsin External Partners:  Aalto University, Otaniemi, Finland Fiscal Year: 2013 Highlight ID: 435
Related Research Emphasis Areas: Advanced Composites Woody Biomass Utilization

For further details log on website :
https://www.fpl.fs.fed.us/research/highlights/highlight.php?high_id=435