4—THE USE OF C¹⁴ AS A TRACER TO DETERMINE THE MOVEMENT OF WATER AND SALT DURING THE DRYING OF A THICK BED OF TEXTILE MATERIAL

Abstract

An account is given of experiments in which a dilute solution of potassium thiocyanate labelled with C¹⁴ was put into a thick bed of textile material to trace the movement of liquid water during drying. It was originally hoped that diffusion effects would be negligible, but it was found that the method actually gave more information on the factors governing the concentration gradients in the bed and on the mechanism of diffusion than on the water movement itself. In the depths of the bed, diffusion is less, and some tentative conclusions regarding water movement can be made, but these are open to considerable doubts.

KEY WORDS (SPECIFIC TERMS):

• THEORETICAL ANALYSIS
• CRITICAL MOISTURE CONTENT
• DRYING
• DIFFUSION
• MOTION
• TRACER TECHNIQUES
• WATER
• POTASSIUM THIOCYANATE
• RADIO-ACTIVE TRACERS
• TERYLENE (TN)
• TEXTILE MATERIALS

KEY WORDS (BROADER TERMS):

• MOISTURE CONTENT
• DRY FINISHING
• TRACERS
• POLYESTER FIBRES