Study On The Comprehensive Evaluation And Efficacy Grading Model Of Waist-back Clips

With the increasing demand of consumers for shapewears,the scale of shapewear market in China continues to expand.However,the vacancy of relevant national or industrial standards leads to the functional exaggeration and the uneven quality of shapewear products.Existing researches mostly focus on the body-shaping effectivity and pressure comfort of breasts and buttocks,the part where shaping bras and pants act.There are few studies on the waist-back clips.Existing researching results mainly focus on the pressure threshold of human body and the prediction model with comfort or pressure values as the main output,which show poor uniformity and practicality.Taking waist-back clips as research objects,this paper aims to establish the efficacy grading model of waist-back clips by exploring the pressure and efficacy.Totally 31 pressure measurement points were set on the main parts of human body(shoulder axillary,lower chest circumference,waist circumference and abdominal circumference).Objective pressure measurement experiments were conducted to measure pressure values at each point when 10 subjects wore three waist-back clips and two elastic shapewears(as control).The position of pressure measuring points and the differences of dressing states are analyzed.It is found that the pressure values of 3# is higher than 1# during the same waist-back clips,while the pressure values of measuring points on steel bones is mostly higher than that on fabrics.The efficacy of waist-back clips was defined as the body-shaping effectivity and the posture-correcting effectivity.Three-dimensional body scanning experiments were conducted,and mathematical tools such as Imageware and Matlab were used to process data.Finally,quantitative evaluation indicators were extracted,combining the influence of fabric thickness calculation.Perimeter changes of lower chest circumference,waist circumference and abdominal circumference are 0.2%-4.76%,0.48%-5.8% and 0.09%-5.17%.Width changes of lower chest circumference,waist circumference and abdominal circumference are 0.16%-9.53%,2.36-16.03% and 0.09%-5.17%.Thickness changes of lower chest circumference,waist circumference and abdominal circumference are 0-11.99%,0-15.21% and 0-8.91%.The efficacy order of dressing states is A2-3# > A1-3# > A3-3# / A2-1# > A1-1# > A3-1#.It is found that the comprehensive ranking of waist clamps’ efficacy is A2# > A1# > A3#,during the same dressing states.Aiming at the problem that the ranking of pressure values at each measurement point of the six states is not uniform,the pressure of waist-back clips on the lower chest circumference,waist circumference and abdominal circumference is comprehensively evaluated by concentrated ordering of lumping fuzzy suggestions,which is completely consistent with the ranking of efficacy(A2-3# > A1-3# > A3-3# / A2-1# > A1-1# > A3-1#).Contrasted with stretching shapewears,the comprehensive evaluation results of pressure are A2-3# > A1-3# > A3-3# / A2-1# > B1# > A1-1# > A3-1# > B2#,and the comprehensive evaluation of efficacy are A2-3# > A1-3# > A3-3# / A2-1# > B1# / A1-1# > A3-1# > B2#.The difference between above shows that supporting steel bones of waist-back clips are beneficial to enhance the efficacy,which means waist-back clips have a more positive efficacy on the changes of perimeter,width and thickness of body circumferences.Product grading methods can be summarized into three categories: simple classification,direct classification and indirect classification.Represented by comprehensive pressure values,the indirect classification method was used to grade the efficacy,and the efficacy grading model of waist-back clips is established: when the comprehensive pressure values of each circumference are 0-1.8 k Pa,1.8 k Pa-2.4 k Pa,2.4 k Pa-3.4 k Pa,the efficacy grade of waist-back clips should be level Ⅰ,Ⅱ or Ⅲ.Finally,the applicability of the grading model obtained is discussed,and the optimized model of waist-back clips based on the average pressure is established: when the average pressure values of each circumference are 0-1.4 k Pa,1.4 k Pa-2.1 k Pa,> 2.1 k Pa,the efficacy grade of waist-back clips should be level Ⅰ,Ⅱ or Ⅲ.