OPTIMIZATION OF PROCESS VARIABLES FOR QUALITY IMPROVEMENT IN PLYWOOD AND ALLIED PRODUCTS.

The process variables involved in the manufacture of plywood have been effectively screened by using Plackett-Burman design for determining the significance of these variables on the end quality of plywood as given by the glue shear strength. The moisture content of the veneers, hot press platen temperature, content of NH//4OH in the catalyst for urea-formaldehyde adhesive and panel pressure were found to be significant in the decreasing order of their influence on the end quality of plywood. The above variables along with the ratio of resin to water (an index of the viscosity of the adhesive) were optimized for maximum strength using the response surface methodology. A first order design was found adequate.