American woods as regards their adap- 

 tability to standard pulp-manufactur- 

 ing processes, their yields, chemical 

 consumption, bleaching characteristics, 

 and other factors of production. Ap- 

 plying and amplifying the results, 

 present studies are centered on the 

 development of useful pulps from 

 important species and regional groups. 



In the Northeastern and Lake States 

 the stands of second-growth hard- 

 woods — maple, birch, beech, and aspen 

 — that have sprung up in the wake of 

 logging offer possibilities as a sup- 

 plementary source of pulp wood. Ex- 

 periments with these woods are being 



M-26174-F 



Pulping experiments over a wide range of 



chemical concentrations and pressures are 



made possible by use o£ a chrome-nickel 



lined digester. 



carried forward. It has been shown 

 that in the grinding of hardwoods a 

 proper dressing of the stone surface 

 will pulp the wood with minimum 

 destruction of fiber length, and also 

 that if the high pentosan content of 

 these species is retained in chemical 

 pulps, much stronger papers can be^ 

 produced from them than had been 

 thought possible. Studies of aspen 

 pulping have been especially helpful 

 in increasing paper production from a 

 prolific species that at present has few 

 uses. 



The Laboratory has devoted special 

 attention to the production of news- 

 print from southern woods. Because 

 of the large tonnage of newsprint 

 consumed by the United States and 

 the fact that much of this is imported 

 from abroad, the possibilities of devel- 

 oping a domestic source of supply, 

 particularly from the plentiful southern 

 species, has commanded increasing 

 interest. However, certain disadvan- 

 tages such as poor color and high resin 

 content in the pines, particularly the 

 older stands, in contrast with the 

 eminently suitable properties and cheap- 

 ness of northern spruce have retarded 

 any realistic development of a news- 

 print industry in the South, although 

 experimental sulphite and ground-wood 

 pulps of newsprint grade were produced 

 at the Laboratory more than 20 years 

 ago. 



Increasing costliness of spruce and 

 balsam, combined with the fact that 

 the young second-growth pine is fairly 

 free from heartwood and relatively low 

 in resin, has tended to renew research ^ 

 efforts in newsprint production andW 

 experiments at the Laboratory and 

 elsewhere. By selecting young pine 

 trees of limited heartwood and resin 

 content, newsprint-grade papers have 



30 



