Parametric study and shrinkage modelling of natural rubber sheet drying using COMSOL multiphysics

Natural rubber is one of the major exporting cash crops in Thailand. Shrinkage in natural rubber sheet during drying creates uneven stresses in the rubber, hampers the quality and the water activity predisposes it to microbial activation. Hence, the effect of drying parameters on shrinkage has been considered in this work. The finite element concept coupled with the arbitrary Lagrangian-Eulerian (ALE) method was used to solve the two-dimensional coupled physics in the rubber sheet drying chamber and account for the shrinkage effect. The spatial domain (drying chamber), material domain (rubber sheet) was analysed. An isotropic linear elastic model was assumed for the rubber sheet for analysis. Three Case studies of different velocity, temperature, relative humidity and shrinkage coefficient were considered in the numerical study using COMSOL Multiphysics. It is concluded that increase in the operating parameters increases the shrinkage of the rubber. Therefore, rubber should dry at relatively lower operating parameters to improve its quality.