3034 Chapter 24 



With either one-ply or two-ply faces, panels with random cores had most linear 

 stability parallel to the grain of outermost face veneer. 



Expansion across the grain was least with one-ply faces if cores were oriented; 

 with two-ply faces, random cores yielded most stability, as follows: 



Face and core Across-the-grain expansion 



construction VPS 5-hour boil 



Percent 



Single veneer 



Random 1.03 1.31 



Oriented .28 .54 



Three-layer .60 1.50 



Two veneers, cross laminated 



Random .48 .48 



Oriented .82 1.16 



Three-layer .57 .63 



Veneer thickness was correlated with linear expansion across the grain of face 

 plys in panels with random cores; thick veneer caused large linear expansion, as 

 follows: 



Face construction and Across-the-grain expansion 



veneer thickness yPS 5-hour boil 



Inch -Percent 



Single veneer 



1/10 2.00 1.62 



1/16 .62 1.79 



1/24 .48 .52 



Two veneers, cross laminated 



1/10 .71 .57 



1/16 .46 .46 



1/24 .25 .42 



Thickness swelling. — Average thickness swell ranged from 22 to 57 percent 

 in the 5-hour boil and from 20 to 32 percent in VPS. The 5-hour boil consistently 

 caused more swelling than did VPS test. In both tests face construction and 

 veneer thickness interacted, as follows (data from table 24-26): 



Face construction and Thickness swell 



veneer thickness VPS 5-hour boil 



Inch Percent 



Single veneer 



1/10 30.0 56.4 



1/16 24.9 47.2 



1/24 24.8 49.2 



Two veneers, cross laminated 



1/10 20.7 25.3 



1/16 24.5 31.9 



1/24 24.3 34.5 



