Perfect dry pressing could only be attained if the mix possessed the properties of water in so far as pressure transmission is concerned. There are many factors, however, which tend to interfere with the transmixxion sic of pressure in the clay block, such as, - Differences in grain size, friction between the grains, entrapped air, dragging of the clay on the sides of the mould box and many other minor causes. In an effort to solve some the problems that are of vital interest to the Dry Press industry, the Committee on Dry Press Process of the National Brick Manufacturers Association has carried on extensive research at the Missouri School of Mines and Metallurgy, Rolla, Mo. --Introduction, Page 1
