Characterization Of Fabric Bending And Stiffness Test Based On CHES-FY System

Fabric stiffness is a basic property of fabric, which directly affects hand feeling and thecomfort of wearing; Fabric formability directly affects people’s visual feeling, therefore it is adecisive factor for apparel application, and it is also closely related to bending, friction, tensilemechanical properties. Fabric stiffness can be achieved by the basic performance test andmethods of mathematical statistics,but the latter one is significantly influenced by social and thesubjective factors.The CHES-FY system studied in this paper is based on quasi three-point bending theory,fabric properties such as weight, bending, friction, tension and compression can be obtainedfrom one single measurement, so it is better in describing fabric style synthetically.This paperused CHES-FY system which is based on the principle of one measure using the same system.(1) By the way of getting the fabric pulling force—displacement curve through one pullingout, the characteristics of fabric bending, friction was extracted, tensile stage indicators throughone pulling out: left slope, left area, peak (X, Y), right slope, right area, average force value,slope, area, combined with fabric weight of one square meter, used10factors in total to describethe fabric stiffness. Orthogonal experimental method was employed to analyze the distancebetween spring chuck(50mm、55mm、60mm、65mm)，the distance from spring chuck to fixedpins (45mm、50mm、55mm、60mm)，diameter of fixed pins (2mm、4mm、6mm、8mm)，distance between fixed pins（3mm、3.5mm、4mm、5mm） four factors,4levels for every factorto design16groups orthogonal experiment, SPSS Factor Analysis Method was used to reduce10factors to2or3factors. Factor1can reflect fabric stiffness, which is defined as stiffnessfactor.According to the component coefficient of the10factors in factor1, the value of thestiffness factor of each fabric sample in each group, except group4without abstracting anyindicator, analysing15groups rank of stiffness factor and subjectivity were analyzed, thecorrelation coefficient was between0.64and0.73. According to Pearson correlation coefficient,the largest coefficient obtained is the16th group, the parameter combination of which is as following: distance between two spring chucks is65mm, distance from spring chuck to fixedpins is60mm, diameter of fixed pins is2mm, distance between fixed pin is4mm.(2) The bendability is the main factor for eveluating the fabric stiffness. Based on thepredecessor’s research for the fabric bendability, this topic is further studied. In this paper, thetypes of samples are broader, including nonwovens, composite materials, knitting fabrics andwoven fabrics. Also, the CHES-FY System is adopted to produce the curves characterizing thefabric bendability. These curves mainly includes the left slopes, the area and the peak value Y.By comparing these curves and the bending length obtained by slant method, heart-shapedmethod and using the Multiple Linear Regression of SPSS statistic software, these two methods’regression equations among fabric bending length and the left slopes, the area and the peak valueY are obtained. When slant method is adopted, the bending length=1.891+0.796*weftslopes-0.099*peak value Y+0.011weft area; When heart-shaped method is used, the bendinglength=4.878+0.455*weft slopes-0.109*peak value Y+0.016*weft area. After verification, it canbe seen that regression equation can meet the hypothesis of linear and homoscedasticity andshow better imitative effect. After the CV value of bending length obtained by equation, the slantmethod and heart-shaped method are compared. It can be found that the CV value produced byCHES-FY system is smallest. In addition, the range among the tested parameters and thebending length of slant method and heart-shaped method (maximum absolute error-minimumabsolute error) are calculated, which shows that the CHES-FY system has a more extensivetesting scope.(3) The subjective testing methods for fabric are developed, including two touching methods.By comparing the subjective, objective images and testing results produced by CHES-FYSystem, the conclusion is that the first touching method can distinguish the fabric stiffness verywell. Therefore, the first touching method can be selected as a subjective testing method.