1382 A NATIONAL PLAN FOR AMERICAN FORESTRY 



of pulps in which color is a secondary consideration. Even under 

 these limitations, however, the processes are finding their way into 

 important commercial use. 



PULPING NEW SPECIES 



The need for extending the range of species for pulping has long 

 been recognized, and a systematic survey has been conducted by the 

 Forest Service covering about 100 American woods as regards their 

 adaptability to standard pulp-manufacturing processes. Compara- 

 tive data have been compiled as to yields, chemical consumption, 

 bleachability, and other factors of pulp production from the various 

 species, but the information is necessarily limited and somewhat in 

 the nature of a " base line " for further intensive studies. The specific 

 characteristics and economic importance of a given species determine 

 the special studies to be undertaken. 



The principal weakness disclosed in previous efforts to improve 

 the pulping and papermaking status of particular species has been a 

 lack of what may be termed fundamental information lack^ of 

 accurate knowledge of the chemical composition and minute physical 

 structure of the wood, of laws underlying the behavior of pulps in 

 processing, and of the basic factors in paper manufacture. A great 

 mass of empirical data has been built up at the Forest Products 

 Laboratory and at the mills that is applicable to a given species or 

 a given process, but basic information of general application is largely 

 lacking. Work to supply this need is going forward, but it should be 

 greatly increased. 



From the standpoint of regional distribution, various types of 

 species have to be considered. In the Northeastern and Lake States, 

 the prevailing softwood types spruce, fir, and hemlock have been 

 the mainstay of the American wood-pulp industries, and the direction 

 of progress in the utilization of these species lies in the improvement of 

 the present standard pulping methods or the discovery of new processes 

 that may increase yields and cheapen production. The pines and 

 other species high in resins and extractives that are found in this 

 region offer the same problem as they do elsewhere, namely, how to 

 convert them cheaply into light-colored papers of general utility. 

 The stands of second-growth hardwoods (made up largely of maple, 

 birch, beech, and aspen) that have sprung up following the logging 

 of earlier stands of pulpwood and saw timber throughout a vast 

 acreage in these regions are a potential source of pulpwood. They 

 are of small diameter and of very inferior commercial value at present 

 except for limited uses in soda and mechanical pulping. A much 

 more important use for them is visualized in the form of sulphite or 

 other pulps of wider usefulness and value. Experiments on these 

 lines have been carried forward with considerable success, but the 

 short fiber of the hardwoods still militates against their use in strong 

 papers. It has been shown recently, however, that in the grinding of 

 hardwoods, a proper dressing of the stone surface will accomplish 

 disintegration of the wood with minimum destruction in the fiber 

 length, thus resulting in improved pulps. It is likewise indicated 

 that the high pentosan content of these species may be utilized, if 

 retained in chemical pulps produced from them, to produce much 

 stronger papers than has hitherto been thought possible. 



