22 JACK PINE AND HEMLOCK FOR MECHANICAL PULP. 



lap appeared to be a very good quality; in fact, it will be seen that the 

 fiber of which they are composed is of good length and that there is 

 not nearly as much short material present as there is in the samples 

 of hemlock pulp. 



Commercially it would be possible to obtain better mixed pulps by 

 grinding the different woods in separate grinders and preparing the 

 stones so as to obtain the best quality of pulp from each wood. 



It has been found, by comparing the samples submitted by Amer- 

 ican manufacturers with the standards chosen, that 5 per cent can 

 be classed as No. 1 pulp, 12 per cent as No. 2 pulp, 12 per cent as No. 

 3 pulp, 61 per cent as No. 4, and 10 per cent as No. 5. Comparison 

 of the experimental pulps with the commercial standards shows that 

 mixed pulps particularly compare well with the No. 4 standard, for 

 which there is evidently the greatest demand. 



SAMPLES OF PAPER PRODUCED. 



In order to determine the adaptability of the pulps obtained in the 

 experiments to the manufacture of paper, a number of test paper runs 

 were made with the pulps which gave greatest promise. Samples of 

 the paper obtained accompany this report. All of the sheets of news 

 paper were made on a machine in the Port Edwards mill of the 

 Nekoosa-Ed wards Paper Co. This machine is 116 inches wide, and 

 the sheet produced, trimmed, was 109 inches. The machine was 

 operated at a speed of 465 feet per minute, and no changes were made 

 in weight of sheet or speed after the beginning of the test; in fact, 

 throughout the runs the conditions were maintained as nearly con- 

 stant as possible. The finish on the paper was obtained by passing 

 the sheet nine times through a 12-roll calender stack. In each case 

 three 1,500-pound beaters of stock were run into sheet in order to 

 have the test continuous over sufficient time to give an idea of its 

 operation on the paper machine. It was intended to by-pass the 

 Jordan engine, but this being impossible, the stock was passed 

 through the engine and the roll set up only slightly. 



Running changes were made in each test, and no difference was 

 found with any of the sheets excepting jack pine. This material 

 was somewhat pitchy, and after an hour's run it was necessary to 

 remove the dandy, since it began to pick up stock. All of the papers 

 were free on the wire and caused no trouble whatever. 



The samples of paper containing spruce were made up for the pur- 

 pose of comparison. It will be seen that, with the exception of color, 

 the sheets differ little, and it is reasonable to suppose that the color 

 could be improved. Allowance should be made for the appearance 

 of the sheets as regards brown shives, these being due to the hem- 

 lock sulphite used, and not to the ground wood. Data on the beater 

 "furnish" for the various papers are given in Table 10. Table 3 

 gives a comparison of strength of the various sheets. 



