Abstract

Formaldehyde release tests of leather with porous structures were carried out according to ISO 17226-3 standard-sealed jar method. Effects of temperature on the release behaviour were investigated. The formaldehyde emission model in sealed system was established according to the law of mass transfer under several reasonable assumptions and verified by the fitting of actual release data. The results showed that formaldehyde emission could be divided into three stages: the linear free release, barrier release and chemical release stages. The linear release time inversely correlated with mass transfer coefficient of leather. The temperature had a significant promotion impact on release during linear release time. The higher the temperature was, the faster the formaldehyde release. Different types of leather showed different release characteristics because of porosity. The average release speed for sheepskin was faster than that of cowhide at the same temperature. However, with the increase of temperature, the increase in the rate of release speed of cowhide was greater. From 30°C to 60°C, the speed for sheepskin increased 19.39% for every increase of 1 degree Celsius by average, and that of cowhide increased 29.92%.