ROSIN When Poorly Strained Is Much Reduced in Quality

It is conservatively estimated that poorly strained rosin annually costs the producers half a million dollars and the users of rosin at least a million dollars for additional processing and loss of material, and in the decreased value of the rosin. The demand for brilliant, clean rosin, entirely free from dirt and specks of all kinds, is greater than ever before. The development and application of better methods of straining therefore is a real need of the naval stores industry.

Dirt in rosin is costly for several reasons. The presence of dirt makes rosin unfit for some purposes for which it would otherwise be suitable, and thus curtails the uses for rosin. The dirt must be removed to keep it out of the products made from rosin, and this cleansing process is expensive. But most important, dirt degrades the rosin, making it a grade lower than it would be had it been properly strained. It is not primarily the large, readily settled, and separated particles that cause the greatest loss, but rather the fine pieces of bark, sand, and clay that are hardly visible in the most critical examination that are most harmful and give the most trouble.

These facts have been fully established by the laboratory work in the naval stores section of the Bureau of Chemistry and Soils. Straining practices must be efficient before the naval stores industry can be on a sound basis. A study of the straining of the gum both before and after distilling is the first major problem to be worked out to a practical solution at the naval stores experiment station which it is planned to locate in the naval stores belt. The laboratory work has shown that the practical solution of this problem of long standing can be worked out only with the complete facilities afforded by a naval stores experiment station, where the problem can be attacked from all angles.