DEVELOPMENT OF COATING COLOUR FORMATION FOR DUPLEX BOARD BASED ON PLACKETT BURMAN STATISTICAL DESIGN

摘要

Coated paper and paper-board are layered constructions.The sheet surface is coated with a thin pigment layer which improves its printing and optical properties,especially gloss,brightness,smoothness and surface strength.Investigations have been made to use the statistical experimental design based on Plackett- Burman design methods,regression estimation,optimisation techniques and alogrithms for application on duplex board obtained from Indian Industries.The pigment,the binders and other ingredients used are China clay,TiO_2,CaCO_3,latex,carboxy methyl cellulose (CMC),starch and NaHMP (sodium hexa meta phosphate) with variable solid contents.Experiments have been conducted on a laboratory air knife coater with system and equipment variables,such as air pressure,number of nips or passes through calender nips,knife angle,calendering pressure at fixed temperature.The output variables like brightness,gloss,smoothness,and surface strength (IGT) were studied and regression equations were developed.The predicted properties for each model derived from the statistical design are compared with the data from standard tests as per TAPPI specifications.The predicted values are found to be within reasonable accuracy for engineering estimates.The methodology can be used for prediction for process selection better than the existing traditional techniques.