Abstract
Some physical properties of tablets, each made from dried milk, pure cocoa, sugar and their mixed powder were studied.
The powder were pressed at various stress and cylindrical tablets of 3.0cm in diameter, 0.7-0.5cm in hight, weighting 5-8g were prepared. Generally, the density of the tablets were proportional to logarithmic upper compressional stress or lower stress acting at the lower punch.
The relationship between upper and lower punching stress has very complex behavior by the various effects of lubrication and anomalous propagation of compressional stress in powder. Those relations were attributed to the component and shape of powder.
With regards to almost all tablets, the destructive intensity were increased with compressional stress, except the tablet made from whole milk powder which led to oiling off by compression. Only a tablet made from whole milk powder exhibited 80% oiling off by compressional stress of about 500kg/cm2 or over.
The rate constant K of the water vapor absorption for the tablets were experimentally determined by the use of Pain's relation at a lower relative humidity. The value of K at 32% relative humidity was 26.0×10-4hr-1 for the tablet made from whole milk powder and 32.0×10-4hr-1 made from dried skim milk, respectively.
