A Dia KNxiAi. UiAOKi) 



and individuals outside of tlic lahoratorv. as well as for routine identi- 

 fication within tlie organization. 



/// the Use of Jfood for Pulp and Paper 



One of the most eoniprehensive investigations eonipleted i)y the 

 lahoratorv is the one on the grinding of wood for niechanieal pulj). 

 whieh was eondueted in a full size experimental ground-wood mill 

 esj)ecially constructed for the })urpose at W^uisau, AVisconsin. 



This study hrought out the fundamental principles underlying 

 the grinding process and the effect of certain variahles such as press- 

 ure, speed and (juality of grinding surface uj)()n the (luality and 

 amount of pulp. The effect of preliminary steaming of the wood upon 

 the pulp was determined for a numher of species, and the suitahility 

 for mechanical pulp of a large numher of American woods was deter- 

 mined. In fact, experiments were carried out on all species which 

 seemed to have any possihilities whatever; it l)eing the intention to 

 make the study so nearly complete that no further work would have 

 to he done upon grinding for many years to come. 



Studies of similar hreadth and scope have heen under way for 

 many years in the production of chemical pulps from American woods. 

 Two princi])al ohjects have heen aimed at. viz.. to determine the funda- 

 mental cooking or jndping conditions underlying each of the three 

 principal chemical processes (sulphite, sulphate and soda), and to 

 determine the suitahility of the individual species for the ])rodiiction 

 of pulp hy the process or processes to which it is a(la})ted. These 

 studies were not (piite completed when war actixities made it necessary 

 to ahandon them for the time heing. They have since, however, heen 

 finished and the results made availahle. 



]Most paper is hought and sold ui)on specification, and the speci- 

 fication usually has some proxision concerning the physical properties. 

 Methods of determinijig these properties have heen very unsatisfac- 

 tory, however, and knowledge concerning the sul)ject lacking. A 

 special testing room in which the atmospheric conditions can he ke])t 

 constant, has heen constructed and series of tests made to develop the 

 inter-relationshi]) among the various ])hysical pro])eii:ies and to im- 

 prove methods of test. The effect of atmos])heric moisture upon the 

 strength of paper has heen determined, and several new methods of 

 test perfected. 



