A look at and a result of reorganized drying research at Forest Products Laboratory

Drying research at the Forest Products Laboratory began with the late Harry Tiemann, considered the father of drying research in this country. However, past accomplishment does not ensure continued research benefits, and the pressure for research dollars during the past few years has forced our Laboratory to focus research activities on studies likely to be of major benefit to the Nation. We have, therefore, asked ourselves what, if anything, in drying research has a good chance of paying off to the public. This self-examination revealed a possible nearsightedness in our development of drying research efforts over the past few years. Perhaps, we have been guilty of considering the drying process independent of the other parts of the processing system. Have we given enough consideration to the fact that the source of our raw material is a tree--not a green chain? Papermakers have greatly influenced forestry research and forest management practices over the past few years. Their efforts are aimed at growing more pounds of fiber per acre by genetic and silvicultural improvements. Have we, who are concerned about the drying of lumber, even suggested to a forest geneticist that perhaps he should be breeding trees that will dry without degrade? In fact, could we who concentrate on the drying of lumber even tell a forest geneticist the kind of tree we would want even if he were willing to breed a tree type for drying purposes? Have we been too complacent in accepting the con cept of natural variability in the drying properties of wood? Have we given enough attention to the real causes for this variability in drying behavior? At the Forest Products Laboratory we concluded that we have been overlooking some of these points; thus, this paper--to briefly describe some of our efforts to amend the situation. First, we examined the relationship of the drying process to the entire tree-processing system. We remember that the cost of drying per se is not a critical factor; the critical factor is the total-processing cost. Obviously, a reduction in drying costs is not acceptable is some other processing cost increases concomitantly that is greater than the reduction in the drying costs. Equally important, perhaps equally obvious, is that it is possible to spend more money on the drying operation if cost savings somewhere else in the processing sequence offset this increase in drying cost. You are all aware of these points, but sometimes when we plan drying research we tend to overlook the entire processing system and focus narrowly on the simple drying operation. Does this also happen in actual production situations? At the Forest Products Laboratory we reorganized our various processing research efforts into a single work unit to better correlate our research in areas such as machining, drying, and gluing. Because these operations are closely related in manufacturing sequence, it seems logical that they should be treated so in the research efforts as well. Secondly, we began to look at the tree as the source of our raw material rather than to consider simply the sawn cant or plank as the source. In reviewing the information on drying from this viewpoint, it became obvious that factors in addition to the usual grain direction,