Moisture diffusion within shredded tobacco leaves.

Abstract

The mechanismof moisture transfer into shredded tobacco was investigated in connection with moistening process control in cigarette manufacturing. For shredded tobaccos of less than about 1.0mmshred width, the moisture was sorbed mainly through the cut faces rather than through the leaf epidermis, indicating that the moisture diffusion within the leaf was the rate limiting step of moisture transfer. The moisture diffusion coefficient values within the cured tobacco leaf ranged from 8.80x 10~7 to 64.2x 10~7cm2-s~1 depending on the type of tobacco, the shred width of tobacco and the temperature at sorption. But these values were not affected by the relative humidity at sorption. The entire moisture transfer into the shredded tobacco leaves was predictable with the diffusion theory.

Influence of Physicochemical Characteristics on the Effective Moisture Diffusivity in Tobacco

“…The results are consisted with Walton et al, who observed that D eff varied from 0.7×10 − 15 m 2 s − 1 to 5.2×10 − 14 m 2 s − 1 during the desorption and adsorption in the tobacco[14] Samejima and Yano (1985) [20]. reported that D eff in cured tobacco leaves ranged from 8.80×10 − 11 m 2 s − 1 to 64.2×10 − 11 m 2 s − 1 depending on the type of tobacco and on sorption temperature.…”

“…Samejima et al [20] reported that the difference in the moisture diffusion coefficient between air-cured and flue-cured tobacco reflects the difference in porosity. The simple correlation analysis results show that the effective diffusion coefficient was significantly influenced by specific pore volume.…”