Application of quality control and other statistical methods to the precision wood industry

Abstract

Investigations were conducted of the statistical aspects of basic research, engineering development, and economic problems pertinent to the Lane Company, Altavista, Virginia, cedar chest manufacturer.

Estimations were made of the quality level and variability of various manufacturing operations, e.g., the veneer slicer, gang saws, hot plate press, planers, sanders, top panel inspection, and finish inspection. Statistical quality control procedures were established at points in the processes most feasible for and responsive to their application.

A thorough study was made of available data on chests returned by consumers because of open corners. The percentage of returned chests was related to differences in case size and to differences in the predicted equilibrium moisture content of wood in the plant during manufacture. These relationships were presented as a basis for determining the months of the year during which it will be economically profitable to 3-ply chests of various sizes as a protective action against returned chests.

An experiment was designed to estimate the effects of high humidity conditions on the rupture of the corners of cedar chests having different panel constructions, corner constructions, and glue treatments. A proposed design with an outline of the analysis was presented.

Some thought was directed to the measurement of the moisture content of cedar wood. It was proposed that a combination of both oven-dry and electrometric methods, rather than by an extraction-distillation method alone, might be employed to estimate more precisely the true moisture content under industrial conditions.