Structural Flakeboards and ComfX)sites 3037 



Modulus of elasticity. — Average MOE in stress parallel to the grain of face 

 plys was 1 ,050,000 psi for panels with single 1/24-inch veneers over an oriented 

 core, and ranged to 1,980,000 psi for those with two 1/16-inch veneers cross- 

 laminated on each face over an oriented flake core (table 24-28). MOE varied 

 significantly with thickness of face veneers: 



Face construction and MOE 



veneer thickness Stressed parallel Stressed perpendicular 



(1) (2) (3) 



Inch -psi 



Single veneer 



1/10 1 ,844,000 344,000 



1/16 1 ,500,000 650,000 



1/24 1,231,000 838,000 



Two veneers, cross-laminated 



1/10 1,928,000 — 



1/16 1,960,000 — 



1/24 1,543,000 — 



From column 2 it is seen that, except for panels with 1/10-inch veneer in two-ply 

 construction, MOE parallel to the grain increased with increasing veneer thick- 

 ness. For one-ply faces, MOE across the grain decreased as veneer thickness 

 increased (col. 3). 



Face and core construction interacted to affect MOE as follows: 



Face and MOE 



core construction Stressed parallel Stressed perpendicular 



Psi 



Single veneer 



Random 1,731,000 314,000 



Oriented 1 ,393,000 735,000 



Three-layer 1 ,462,000 781 ,000 



Two veneers, cross-laminated 



Random 1 ,737,000 — 



Oriented 1 ,906,000 — 



Three-layer 1 ,788,000 — 



When stressed parallel to the grain of outermost veneers, panels with two 

 veneers on each face and with oriented cores had highest MOE ( 1 ,906,000 psi); 

 panels with two-ply faces and random or three-layer cores did not differ much in 

 MOE. Panels with single veneers on each face had greatest MOE if fabricated 

 with random cores (1,731,000 psi). 



MOE across the grain of panels with single veneers was lowest for random 

 core construction. 



