BULLETIN No. 343 § 
Contribution from the Forest Service 
HENRY S. GRAVES, Forester 
PROFESSIONAL PAPER April 26, 1916 
GROUND-WOOD PULP. 
4 ’ By J. H. Tuickens, Chemical Engineer in Forest Products, and G. C. McNaucuton, 
; Engineer in Forest Products. 
CONTENTS. 
' Page. Page. 
me©bject of the bulletin....-..-........2..5..-: 1 | Part I—Contd. 
i Present status of the ground-wood industry. 2 The effect of variable grinding conditions. 17 
_ Present methods of manufacture.........--- 6 | Part II— é 
Part I— Experimental and commercial tests on 34 
} Equipment used in the experiments. - .- 7 Warlous;woodSs...-.c22et es --ee ee see tee 67 
Methodsemployed in experimental tests. OU Ap pen dixs (AG sea ae ESRI REN ae ters ea 
Effect of preliminary treatment of spruce. Lie AD pendix Biasesescer es eetiae ae Racer este 151 
OBJECT OF THE BULLETIN. 
_ This bulletin presents the results of tests on (a) the grinding of 
! steamed or cooked spruce for mechanical pulp and (6) the results 
_ of tests on a number of American woods to determine their suit- 
_ pulp.t_ If the price of news-print paper is to be kept at a reasonable 
figure, more efficient methods of converting spruce into pulp must 
be developed or else a cheaper wood substituted for the former. 
i The results of experiments meant to develop greater efficiency in 
' the grinding of uncooked spruce have already been presented in 
_ Forest Service Bulletin 127, ‘‘The Grinding of Spruce for Mechanical 
" Pulp.”” That bulletin also discusses the influence of the many 
_ 1Acknowledgment is made to Mr. C. P. Winslow, Mr. Henry E. Surface, and Mr. S. D. Wells, engineers 
forest products, and to Mr. S. E. Lunak, assistant chemist in forest products, Forest Service, for aid in 
‘the preparation of this report. Acknowledgment is also due Messrs. G. F. Steele, W. G. McNaughton, 
‘and L. M. Alexander, of the Nekoosa-Edwards Paper Co.,and Mr. D.C. Everest, of the Marathon Paper 
Mills Co., for assistance rendered during the tests; also to Mr. C. W. Knapp, of the St. Louis Republic, 
A and to Messrs. P. W. Schaeffer and E. D. De Witt, of the New York Herald, for providing the presses 
_ upon which the experimental papers were tried out. The maps in this bulletin showing the range of 
__ the various tree species were prepared in the Forest Service by Mr. William H. Lamb, assisted by Miss 
_ Georgia Wharton. 
Notre.—This bulletin contains valuable information as to the use of various species of wood in the manu- 
facture of paper and is of interest to manufacturers and users of paper. 
14852°—Bull. 348—16——1 
