20 JACK PINE AND HEMLOCK FOR MECHANICAL PULP. 



TABLE 2. Conditions of manufacture of spruce ground-wood standards Continued. 



1 To grinder. 



JACK PINE PULP. 



Plates VIII, IX, and X show six samples of ground-wood fiber 

 obtained from jack pine. The data taken during these tests are given 

 in Table 4. There is a very striking likeness between the fiber 

 obtained from jack pine and that from spruce. Especially is this 

 true of the fiber secured by using the natural grit of the pulp stone 

 without any burring. Tests Nos. 7-1, 19, and 13-1 were run by 

 using an excessive amount of power and by sacrificing the rate of 

 production. This wood was ground, however, in the dry state, and 

 unquestionably the same quality of fiber could be obtained with 

 increased production and lower horsepower consumption per ton if 

 it was soaked or steamed. The fibers obtained in tests Nos. 20-1, 

 commercial run No. 14-1, and commercial run No. 24 compare favor- 

 ably with the No. 4 standard, and the production and power con- 

 sumption are more nearly those obtained commercially. There is 

 more short material than is found in the No. 1 or No. 2 standards, but 

 still the fiber is long and fine, and appears to have considerable 

 strength. The illustrations show some of the better fibers obtained. 

 Of course pulp has been made^in the laboratory which was fully as 

 fine as that shown as the No. 5 standard. Some has been made also 

 which is fully as coarse as the No. 3. However, this is rather the 

 exception than the rule. 



The jack pine fiber shown in Plate X (run No. 7-1) was the most 

 pleasing in appearance when in the pulp lap, and was generally con- 

 sidered to possess the best quality. The rate of production, however, 

 was so very low, and the horsepower consumption so high, that it has 

 no commercial importance. 



