6 JACK PINE AND HEMLOCK FOE MECHANICAL PULP. 



industry is to continue, that substitutes be found for spruce pulp, 

 especially in the manufacture of news, wrapping, and other of the 

 cheaper grades of paper. To determine whether there are not other 

 domestic species which will produce a commercial grade of ground 

 wood suitable for the purpose, etc., the Forest Service, in cooperation 

 with the American Pulp and Paper Association, began an extensive 

 series of tests on several of the woods which occur in large quantities 

 in the United States, particularly in the Lake States. The woods 

 which have been tried up to the present are hemlock and jack pine, 

 together with a small amount of spruce, for the purpose of comparison. 

 The experiments were conducted at Wausau, Wis., under the 

 general supervision of the director and assistant director of the 

 Forest Products Laboratory, and an advisory committee of the 

 American Pulp and Paper Association, composed of Messrs. G. F. 

 Steele, chairman Nekoosa-Edwards Paper Co.; W. G. McNaughton, 

 secretary Nekoosa-Edwards Paper Co.; D. C. Everest, Marathon 

 Paper Mills Co.; W. L. Edmonds, Wausau Paper Mills Co.; A. M. 

 Pride, Tomahawk Paper Co.; and Wm. Eibel, Rhinelander Paper Co. 



RESULTS OF EXPERIMENTS. 



Not only have very promising sheets of pulp been obtained from 

 both the hemlock and jack pine, but paper has been made from 

 them on commercial machines, operating at high speed, and under 

 all other conditions of actual commercial practice, which has the 

 strength, finish, and appearance of standard news paper. The 

 production per grinder, the horsepower consumption per ton, and 

 the yield per cord approximate the averages which obtain in the 

 grinding of spruce. Again, pulps composed of mixtures of hemlock, 

 spruce, and jack pine in different proportions have been obtained, 

 which compare very favorably with the ordinary spruce ground wood. 



Hemlock ground wood has a decided reddish tinge, though this is 

 not very noticeable, even in an all-hemlock sheet of news paper. 

 Jack pine pulp is also slightly off in color, but is not nearly as dark 

 as hemlock pulp. Careful study by experts should make it possible 

 to bring the color of the paper produced from these pulps more 

 nearly to the usual white. As it is, the sheets of news paper which 

 have been secured are only slightly off color, though they are the 

 result in each case of but a single attempt to secure the standard 

 degree of whiteness. 



Since the experiments on hemlock have brought out a number of 

 points in favor of the grinding of that wood, two paper-mill com- 

 panies have signified their intention of using it in their cheaper grades 

 of paper. One of these mills has already begun to do so, and is well 

 satisfied with the pulp obtained. 



