GJROUND-WOOD PULP. 



29 



POWER CONSUMPTION PER UNIT OF STRENGTH. 



It has always been known that the consumption of a great amount 

 of power will produce pulp of a greater strength. The relative 

 effect, however, in using different amounts of power is probably best 

 shown in figure 21. The strength as represented by Mullen or 

 Schopper tests increases with increasing power consumption per ton. 



Figure 22, curve A, shows the relation between horsepower con- 

 sumption per ton of pulp per meter of breaking length of paper made 



125- 



136- 



150- 



60 



■d 5o 



CO 



50 



167 Z 45 



o 



UJ 



188- 



2 40 



214- 



250- 



35 



30. 



y— • 



.37 



T27 .28 .29 .30 .31 .32 .33 .34 .35 .36 

 STRENGTH FACTOR-MULLEN TEST IN POINTS PER POUND 



Fig. 19. — Relation of strength of paper to pressure and speed. (Spruce runs 32 to 38, inclusive.) 



from it, and the power consumption in grinding a ton of the pulp. 

 At low values of power consumption greater strength is produced 

 per horsepower than at high values. The horsepower per ton per 

 point per pound is also shown in the same figure, curve B. 



STEAMED WOOD PULP AND ITS USES. 



The pulp made by grinding steamed wood can be used for different 

 purposes, depending largely upon the nature of the grinding process. 

 If a sharp and coarse stone is used a large number of shives will be 

 present and the pulp will serve for the manufacture of box board or 



