Research On Forming Design And Mechanical Properties Of Pressure Fabric For Hypertrophic Scar

Pressure garment is made of pressure fabrics according to specific parts of the body.It is an important treatment method to prevent and inhibit scar hyperplasia after burns.The pressure exerted on the skin comes from the deformation of the pressure fabrics,which is the key to determining the curative effect.At present,pressure fabrics cannot provide lasting and stable pressure due to factors such as structure,and a new type of pressure fabric needs to be developed to meet clinical needs.Elastic covering yarn and fabric structure are important factors to ensure the compression function of pressure fabrics.Therefore,this topic from the structure design of the covered yarn to the structure design of the fabric to deeply study the molding process of the pressure fabric and its influence on the mechanical properties of the pressure fabric,aiming to provide material selection,structural design and performance optimization of the pressure fabric Certain reference.This paper mainly includes the following parts:First,the structure design and mechanical properties of the covered yarn.First,spandex and nylon are used as raw materials,and a total of three specifications of double-covered yarns are designed;then the inner twist,inner-outer twist ratio and spandex draft are used as the molding process parameters to prepare double-covered yarns with different structural characteristics.The appearance and mechanical properties of the yarn were tested;finally,the influence of various process parameters on the mechanical properties of double-covered yarn was discussed.Through orthogonal optimization,the double-covered yarn 40/70/70 for ground weave has the best mechanical properties when the internal twist is 1600 T/m,the internal and external twist ratio is60%,and the spandex draft ratio is 3.0.Through single factor analysis,as the spandex fineness increases,the internal twist of the double-covered yarn decreases,and the internal and external twist ratio and the spandex draft ratio increase.When the inner twist is 1500 T/m,the inner and outer twist ratio is 80%,and the draft ratio is 4.8,the double-covered yarn 210/70/70 for embedding has the best mechanical properties;when the inner twist is 900 T/m,the inner and outer twist When the twist ratio is 85% and the draft ratio is 5.2,the mechanical properties of the double-covered yarn560/70/70 for embedding are the best,and both are better than the double-covered yarn of the same specification on the market.Second,the structural design and preparation of pressure fabrics.First,design the fabric structure of the pressure fabric;then,based on the gradient of the elastic recovery rate of 210/70/70 and 560/70/70 double covered yarns,10 double covered yarns were selected as weft-inserted yarns,and the 40 /70/70 double-covered yarn was used as the ground yarn,and the pressure fabric samples were prepared,and their physical parameters and appearance were characterized.Research shows that,corresponding to the designed organization structure,the fabric’s front and back sides present different appearances: the loops on the front of the fabric are uniform in size,and the surface is flat,soft and tight,which can be used for the skin-friendly side of the pressure fabric;the loops on the back of the fabric are small,and the surface is uneven and grainy,which can reduce fatigue and enhance wear resistance,used for the skin-relieving surface of pressure fabrics.Third,the analysis of the mechanical properties of the pressure fabric and its comprehensive influence on the effect of scar suppression.First,use the constant elongation method to test the mechanical properties of the pressure fabric;then analyze the relationship between the elongation,spandex fineness and the resilience of the covered yarn and the tensile properties and fatigue resistance of the pressure fabric,and combining with clothing pressure,explore the comprehensive influence of the mechanical properties of pressure fabrics on its scar suppression effect.research shows:(1)The elongation rate is positively correlated with the elastic recovery rate and plastic deformation rate of the pressure fabric;the low-resilience covered yarn can make the elastic recovery performance of the pressure fabric better at a smaller or larger elongation;when the spandex fineness increases,the elastic recovery rate of the pressure fabric increases,and the plastic deformation rate decreases.(2)Pressure fabrics with large spandex fineness,fabrics covered with high-resilience yarns have relatively lower stress relaxation rate and constant elongation,and the applied pressure and attenuation are relatively small,while pressure fabrics with small spandex fineness and high resilience covered yarn fabrics have greater stress relaxation and constant elongation.Although the initial pressure is large,it is easy to attenuate and shorten the service life.(3)When the spandex fineness of the covered yarn is large,the fatigue degree of the pressure fabric is low and can maintain stable pressure transmission;the pressure fabric of the high resilience covered yarn shows excellent fatigue resistance in terms of deformation and force value.(4)The pressure fabric of the 560 D spandex covered yarn has a garment pressure of about20 mm Hg,which can inhibit the growth of scars during the treatment of pressure therapy.By adjusting the structure of the yarn,the pressure fabric optimized in this paper has the characteristics of high pressure,high resilience,low stress relaxation and low fatigue.The pressure fabric of 210 D spandex covered yarn is about 10 mm Hg,which is not enough to treat scars.Therefore,it is used in the early and late stages of pressure therapy to play a role in adaptation and transition.