Date on Master's Thesis/Doctoral Dissertation


Document Type

Master's Thesis

Degree Name

M. Eng.


Chemical Engineering

Committee Chair

Barnes, W. R.

Committee Co-Chair (if applicable)

Ernst, R. C.

Committee Member

Ernst, R. C.

Committee Member

Williams, Gordon C.


Rubber, Artificial--Drying


A study of the drying of Buna-S in crumb form (designated as GR-S) is presented in which investigations of vacuum and air drying are made. The drying characteristics are presented and the effect of drying on the quality is evaluated. Vacuum drying is investigated using a shelf and a rotary type unit. The individual effects of temperature, vacuum, thickness of crumb layer, and size of crumb particles are studied. Data are correlated by means of drying rate curves. Comparisons of the effects of the variables are made using these curves. Air drying is studied by the use of a shelf unit with air blowing across the crumb. Air drying also is investigated with air directed through the bed of crumb. The variables studied are: temperature, humidity, air velocity, thickness of crumb layer, size of crumb, and shrinkage of the crumb during drying. The results are presented as drying rate curves and comparisons are made showing the effect of variables. A study of the temperature of the rubber during drying is presented showing the trend as the moisture content changes. The quality of the dried rubber is determined by means of an evaluation of the "gel" content. The gel content is defined as the per cent of the rubber insoluble in benzene. The results of several studies of the effect of temperature on the formation of gel are presented.