Preparation And Simulation Of Thermodynamic Properties Of Heated Fabric Based On Silver-plated Yarn

Intelligent heating garment can provide positive warm for people who live and work in low temperature environment,and local positive warm clothing can effectively relieve pain of patients with rheumatic diseases.Flexible heating component is an important part of intelligent heating garment.However,it has not been reported in some literature to study the safety,comfort and heating performance of flexible heating fabric.Based on these,some heating performances including the equilibrium temperature,heating rate,power density and surface temperature uniformity of silver plated yarn,heating fabric and garment integrated with silver plated yarn were studied systematically.In this paper,firstly,the thermal stability,washing resistance and the curve between the thermal field distribution and the load voltage of the silver plated yarn are studied.Three kinds of silver plated yarn were chosen(Sample one and Sample two:silver plated sewing thread of 28.2 tex and 19.7 tex,Sample three:the silver plated yarn of 9.7tex).The experimental results show that the fracture strength and electrical conductivity of the silver plated yarn both decrease with the increase of aging time and aging temperature.When the aging temperature is 80℃ and the aging time is 360 h,the resistance of the sample one,sample two and sample three increased from 30Ω,37.78Ω,and 82.36Ωup to 128.65Ω,2187.24Ωand 561.52Ω,respectively.The increased amplitude were 328.83%,5689.99%and 581.82%.After 360 h aging at ambient temperature of 80 ℃,100 ℃ and 120 ℃,the fracture strength of the three kinds of samples decreased 26.24%,26.46%and 27.19%。After 10 times of washing,the resistance of the three kinds of samples increased 34.37%、130%and 294.20/%。Under the 5V load voltage,the equilibrium temperatures of the three samples were 65.47℃,48.82℃和27.63℃,respectively.For assessing the safety of silver plated yarn,it is necessary to understand the regularity of silver plated yarn under different load and the internal surface temperature field.Therefore,we constructed a thermodynamic mathematical model and finite element model of silver plated yarn.The heat transfer coefficient of the model was deduced by fitting the value of the heat dissipation coefficient(h)according to the actual testing experience.Comparing with the traditional calculation method of the average value,the results showed that standard deviation variance reduced 1.59%and the calculation results error was less than 7.7%.The experimental results show the effectiveness of the proposed model.And the model can provide experimental and theoretical basis for the design and development of heating and heating apparel.In order to explore the optimal integrated method and preparation process heating fabric including silver plated yarn,the flexible heating fabric were prepared by knitting fabric,weaving fabric and embroidery way.Meanwhile,the equilibrium temperature of the three kinds of heating fabric is closely related to the power density of the heated fabric.Under the 5 V load voltage,the equilibrium temperature of the samples prepared by the three methods can reach more than 60 ℃.The smaller the spacing of silver plated yarn is,the more uniform the surface temperature was.The embroidery method can be used to carry the silver plated yarn in any way to the different fabric substrates.The process of knitting and weaving heating fabric is more complex,and the control method for the integration of silver plated yarn is not as good as the embroidery method.And the preparation of woven fabric wastes more silver plated yarn Then,the performances between the heating fabric and the polypyrrole coated fabric with silver plated yarn were compared.The experimental results showed that the resistance to washing of polypyrrole coated fabrics was worse than that of silver plated yarns.