Analysis And Research On The Testing Method Of Leather Tactile Characteristic Parameters

With the improvement of people’s living standard, consumer requirements for the quality of leather products and the tactile properties of leather are getting higher and higher. The evaluation method of leather tactile properties (mainly including softness, fullness and elasticity) is a subjective evaluation method by leather experts over the years, namely the hand method. Later, it is developed to the tester method which analyzes the relationship between four mechanical properties (compression, top extension, bending, stretching) and leather tactile properties based on the mechanical properties of leather. Leather Tactile Properties Tester is a typical instrument designed by Shaanxi University of Science and Technology (hereinafter referred to as the Tester). In recent years, there are some instruments based on test sensors instead of mechanical testing. Its representative is the phabrometer developed by Nu Cybertek, Inc. But these two kinds of objective test methods have not been widely used in actual production. Therefore, there is an urgent problem to find an objective evaluation method of leather tactile characteristics. This paper focuses on how to use the instrument instead of artificial detection with subjective factors. After we analyzes the research status and existing problems of leather tactile characteristics, the specific jobs are as follows:(1) Analysis of phabrometer for tactile properties of leatherFirstly, a group of cattle leather samples were selected. Secondly, the results of the evaluation were carried out in leather tactile properties by traditional manual method It is showed that phabrometer only judges the leather softness and relative hand value.,This equipment is expensive. and can not meet the requirements in leather test.(2) Analysis of the test instrument for the testing of leather tactile characteristic parametersThe cow leather samples which tested by phabrometer were selected to test compression performance and lastometering property. The displacement-load- time curve were also analyzed. According to the analysis of the parameters of the leather tactile characteristics, the quality of the leather tactile characteristic parameters were determined. Then, these results were compared with the results of expert evaluation. The analysis results show that the Tester can judge the main parameters such as softness, fullness and elasticity. Furthermore, the results are in good agreement with the expert evaluation results. But the Tester is time-consuming, and the operation is not convenient.(3) Structural optimization of test instrumentIn order to improve the test efficiency, several optimization schemes were put forward for the clamping device of the Tester. Schemes included a combinatorial test on compression strength and flexural strength, a combinatorial test on compression performance and top stretch performance, a test on compression performance or top extension performance with multi-point and multi-sensor, and a combination test on compression performance and top extension performance with multi-point and multi-sensor. The pros and cons of these schemes were analyzed. And the results show that the test with multi-point multi-sensor in the compression performance and the top stretch performance are much better than the other tests.(4) The realization way and data processing method in the test by a fingertip skin sensing device were explored.Based on the analysis of the test results of the Tester and phabrometer, the method to determine the tactile characteristic parameters of leather was studied. This method using the fingertip skin leather touch sensing device is a new way to test parameters which considered not only the load displacement parameters but also the physiological factors of touch.The displacement-load-time test method in this paper can be used to detect the tactile parameters of leather which replaces the traditional manual method. Through these tests on the compression parameters and top extension performance, the leather tactile characteristics can be reflected more perfect. After we optimized the clamping device in testing instrument on the leather tactile characteristic parameter, the accurate test and evaluation can be carried out. It will improve the efficiency of the test significantly. This study is important in setting up a machine test standard which has the practical significance and the promotion value.