Numerical modeling assessment of mechanical effect in bovine leather drying process

ABSTRACT

Leather manufacturing involves a crucial energy-intensive drying stage in the finishing process to remove its residual moisture and generates important heat gradients. The numerical model presented in this study has been developed to describe the drying process of porous medium: bovine leather that undergoes deformation due to shrinkage. The mathematical formulation of fundamental heat, mass and momentum transfers’ phenomena during drying summarizes a two-dimensional model considering elastic behavior of bovine leather. The evolution of moisture content, temperature, and mechanical stresses during drying was discussed. The model was validated with experimental results. Numerical simulations show good agreement with experimental results. The study shows that the elastic model keeps the stress sign at the final stage of drying. The deformations induce tensional stresses near the surface equilibrated by compressive stresses within the product. They reached their maximum for normal stresses equal to 5.97 and 3.52 MPa at around 2145 and 868 s, respectively, for normal stresses along x and y directions and then decrease.

KEYWORDS:

• Bovine leather
• drying process
• heat and mass transfers
• strain
• stress

Additional information

Funding

This research was supported by “Tannerie Megisserie du Maghreb” industry as research partner. The authors would gratefully acknowledge the financial support received from them and thank all the team of the TMM industry and especially M. Hechmi Khedira, the management environment responsible in TMM industry.