Production of Pulp 



Preliminary experiments were made to determine 

 the nature of the pulp obtainable from the box- 

 face slab material. The cooking was done in the 

 autoclave described above, the apparatus being 

 standardized by the use of commercial spruce 

 chips. Caustic soda was employed as cooking 

 agent. The washed pulp was disintegrated in a small 

 experimental beater and sample sheets were made 

 up on a hand frame and in a wire stamp. The 

 sheets were dried on a steam-heated dryer-roll 

 designed for the purpose and in some cases finished 

 on a gas-heated calender roll. In this way a rough 

 idea could be obtained of the relative merits of the 

 different pulps for the production of paper. 



Without going into detail, it was found that fibre 

 of good quality was obtainable from the resinous 

 long-leaf pine. Shavings gave low yields of rather 

 short and non-uniform fibre, showing the necessity 

 of preparing the wood in chip form. The pulp 

 from the resinous chips was characterized by favor- 

 able length and strength of fibre. There was no 

 appreciable difference between the pulp obtained 

 from the resinous wood direct and that from the 

 chips which had been first extracted with NaOH 

 or Na 2 COs. The pulp from the resinous chips 

 was harder to handle, because of the large amount 

 of rosin soap mixed therewith. 



The yields of moisture-free pulp varied from 17 

 to 25 per cent of the weight of the original wood, 

 depending on whether the cooking was carried 

 to the point of soft, light-brown pulp or stopped 

 at the "raw" stage to give stiffer, darker fibre. 

 Such yields would be too low to warrant a simple 

 pulping treatment of the wood, although the figures 

 represent the normal yields of 3550 per cent on 

 the basis of moisture-free and resin-free wood. The 

 recovery of rosin and turpentine becomes essential 

 in the treatment of rich wood. 



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