Stretching, Bending, Compression, And The Top Stretch Leather Creep Properties Of The Deformed State,

In this paper, the creep and creep recovery behavior of cattlehide upper leather were studied under various mechanical deformation states. The applicability of generalized Kelvin models in the study of leather creep deformation was investigated. The modified generalized Kelvin model was found to well fit the creep behavior of cattlehide upper leather. By analyzing the rheological constants from the model, the comfort and shape-stability of leather and related products were discussed. With analysis of leather creep of Lastometer deformation at different forces and a suitable curve fitting method to complement data points, a three-dimensional creep diagram of leather was built up. This strain-force-time coordinate diagram can be used to express the creep behavior of leathers successfully and may be used to predict and estimate the creep parameters of leather in some extent.The mechanical model of leather creep recovery at Lastometer deformation state was also studied. Some mathematical models in the Origin software were used to study the leather creep behaviors. The mechanical models were established by the research of leather creep behavior at different deformation states.The mechanical properties of leathers processed in urea solutions were also studied. Such factors as urea concentration and processing time that may affect the mechanical properties of blue leathers and fatliquored leathers were investigated. The structure changes and mechanism of urea processing on wet blues and fatliquored leathers were analyzed, and the differences were discussed. It was concluded that urea processing greatly affects the mechanical properties of leathers.