Structural Flakeboards and Composites 3029 



In late 1979 the Plyboard Corp. in Brownsville, Ore. , commenced production 

 of a composite panel trademarked PLYBOARD; it is fabricated in a one-step 

 pressing operation in which Douglas-fir veneer is pressed over an electrostatical- 

 ly aligned core derived from Douglas-fir planer shavings and sawdust (Keil 

 1980). 



Economic analyses by Springate (1978), Springate et al. (1978), Koenigshof 

 (1979) — who favors the trade name COMPLY — and others, indicated the strong 

 potential for manufacture of southern pine structural composite panels. In 1980 

 Georgia-Pacific Corp. commenced manufacturing such panels — trade named 

 STABLE-X — at their Dudley, North Carolina plant. As in the Potlatch oper- 

 ation, the Dudley mill used a two-step procedure in which cores with cross- 

 aligned flakes are pressed separately and later combined with face veneers in a 

 second pressing operation. 



FURNITURE COMPOSITE PANELS 



Only a few studies of structural hardwood composite panels have been pub- 

 lished; two relate to furniture panels. 



Chow (1970, 1979) found that particleboard stiffness and creep resistance was 

 significantly enhanced by adding hardwood face veneers approximately 1/16- 

 inch thick. 



Suchsland (1971) studied linear expansion of three-ply furniture panels com- 

 prised of hardwood veneer over a particleboard core. The flat-pressed 3/4-inch- 

 thick particleboard cores he used were practically isotropic in the plane of the 

 board; their low coefficients of hygroscopic expansion effectively restrained 

 across-the-board expansion of thin layers of hardwood veneers. Thin veneer 

 crossbands over these thick flat-pressed particleboard cores had little effect in 

 restraining hygroscopic linear expansion of composite panels with hardwood 

 veneer faces; he concluded that expansion of three-ply panels using flat-pressed 

 particleboard cores can be reduced only by reducing the expansion coefficient of 

 the core. 



For 1/2-inch-thick composite sheathing panels comprised of single 1/24- to 

 1/10-inch-thick southern pine veneers over a core of mixed hardwood veneer 

 flakes randomly placed, however, veneer thickness has a significant effect on 

 across-panel linear expansion. (See following subsection.) 



