C—3A

36

Table 8.—Grinding of Tawa at Great Western Paper Co. Mill, Ladysmith, Wisconsin: Log of Grinder-runs— continued.

Table 9. —Grinding of Tawa: Summary of White-water and Fibre Losses in Grinder-run No. 3.

Table 10.—Colour Measurements of Tawa Mechanical Pulp produced from Discoloured Heartwood before and after Washing.

Wood. Production. Date. Shift. Hour. 0 " Pulp Laps. Pulp (dry). surface. T grinding. Backs Wood filled.! ! ground. Wet Moisture Dry p c d Per Weight. Content. Weight 24 Hours. GErar.ER-RUN No. 3. 1028. | Hours. Cords. lb. PerCent. lb. lb. Tons. Feb. 12 .. 1 9.30 a.m. B, C 1.00 p.m. C 3.00 2 4.30 C 5-5 2 .. 3,285 69-9 985 7.30 0 9.30 .. 6-5 4 .. 7,180 69-9 2,160 12-0 6 1-5 10,465 .. 3,145 2,095 2-10 Loss of fibre at white-water saveallj) .. .. .. .. 45 Total yield of pulp (grinder-run No. 3) .. .. .. 3,190 2,125 2-13 * Types of burrs used were as follows : A, smooth roll used for removing old surface ; .It, four-point (four teeth per inch) straight-cut ourr; C, 14-point diamond-cut burr; 1), 12-point diamond-out burr. All burrs were new. They were used in the order indicated, t Average pressure in cylinder, SO lb. For other conditions see Table 7. j One rack equals 1 cord. These were the number of racks filled on each shift, and not the number of racks ground. § See Table 9.

Time. Average Samplo Fibre Total Overflow Fibre lost in No. per 1,000 Gallons. during Period. WhiteWater. From. To. lb. Gal. lb. 1 10.05 a.m. .. 3.23 p.m. .. 5-3 4,340 23-0 2 3.23 p.m. .. 6.46 p.m. .. 4-5 564 2-5 3 6.46 p.m. .. 10.45 p.m. .. 4-5 4,546 20-5 Total for the .. .. j .. 9,450 45-0 run

Primary Colour. Secondary Colour. —— White. i —> — ■ ■ i' • ■ 1 Hue. Luminosity. Hue. Luminosity. Per Cent. Per Cent. ' Per Cent. Before washing .. 1 34 Orange .. 9 Red .. 0-19 After washing .. I 46 Orange .. 9 None ..