Chrome free leather more envirenment friendly

Chrome free leather character and importance
Due to ecological legislation in many countries which can be expected to increase in future; it will become more difficult to dispose of chrome-containing waste at economical prices. Therefore procedures have been developed in the last few years in order to reduce or eliminate the large quantities of chrome, shavings and thus to avoid their disposal on dumps for hazardous waste. This has been achieved by chrome -free preliminary tanning and by a shrinking temperature which is adequate for perfect shaving in the wet condition. The leathers produced by such a procedure are “wet white” leathers.
Chrome-free leather has gradually gained commercial importance, particularly for automobile upholstery applications. In many respects, however, chrome-free leather is inferior to chrome-tanned leather. UV and heat are known to be more detrimental to chrome-free leather than to chrome-tanned leather, especially in regard to the colorfastness of dyestuff and mechanical properties. Temperature, UV radiation, and humidity are key environmental factors that affect leather properties. The role of humidity and its interaction with UV radiation and temperature on leather properties, however, are not clear to the leather industry, and this information is needed for formulation of antioxidants that will protect chrome-free leather from UV and heat damage. Therefore, a systematic study was performed to formulate the relationship between these three environmental variables and resultant colorfastness and mechanical properties. A second order regression equation was derived to plot response surfaces that clearly illustrate the relationship between the environmental variables and colorfastness, as well as the resultant physical properties. Observations showed an intriguing interaction between humidity and radiation dosage. Measurements revealed that an increase in humidity resulted in a decrease in colorfastness and mechanical strength. However, after the UV radiation dosage reaches a certain level, an increase in humidity may actually help maintain both properties. Observation showed the stiffness decreased steadily with humidity, whereas the toughness index slightly increased with humidity. This study also used differential scanning calorimetry (DSC) to determine the denaturation temperature as a function of various environmental conditions. We observed a correlation between colorfastness and the denaturation temperature.