2924 



275 



Co 225 



175 



Uj 



^ 125 



INITIAL TEST 



Chapter 24 



ACCELERATED AGING 



75 



50 



40 - 



30 



20 



10 



I.I 



1.2 



1.3 1.4 I.I 1.2 



COMPACTION RATIO 



1.3 



1.4 



Figure 24-6. — Internal bond strength related to compaction ratio in 1/2-inch-thick 

 southern red oak and mockernut hickory panels made from 2-1/4-inch-long, 0.020- 

 inch-thick flakes cut on four types of flakers. Panels fabricated at the target density of 

 52.6 Ib/cu ft are accentuated. (Left) Initial strength at 50 percent relative humidity. 

 (Right) Strength after accelerated aging cycle. (Drawing after Price and Lehmann 

 1978.) 



NITIAL 



ACCELERATED AGING 



ALL 

 FLAKERS 



RING 



DISK 



LATHE 



DRUM 



225 275 20 40 



INTERNAL BOND (PSD 



Figure 24-7. — Effect of 5- and 8-percent phenol-formaldehyde resin content (RC) on the 

 average internal bond strength of 1/2-inch-thick southern red oak and mockernut 

 hickory panels made from 2-1/4-inch-long, 0.020-inch-thick flakes cut on four types 

 of flakers. Panels were fabricated at a target density of 52.6 Ib/cu ft. (Left) Initial 

 strength at 50 percent relative humidity. (Right) Strength after accelerated aging 

 cycle. (Drawing after Price and Lehmann 1978.) 



