Research On Thermal Insulation Property Of Cold Protective Clothing Made Of Coffee Carbon Fiber

When engaged in outdoor operations at low temperature without heating,people need to wear cold protective clothing to avoid environmental damage to the body.With the improvement of living standards,people’requirements for cold protective clothing are gradually increasing.The traditional cold protective clothing mostly use wadding such as down,down cotton,which have limitations in thermal insulation property and comfort.With the development of technology,some new thermal fibers with excellent performance have gradually emerged,which have great market development potential.Therefore,exploring new types of wadding has become one of the research direction for the development of cold protective clothing.In addition,the market has no uniform standards for the optimal filling density of new types of wadding and the ease allowance of cold protective clothing.Wearing the cold protective clothing with unsuitable filling density and ease allowance will not only affect the thermal insulation property,but also easily cause frostbite.Starting from the three main factors affecting the thermal insulation property of cold protective clothing--wadding,filling density and air gap,this paper explores the influence of different wadding,filling density and air gap on the thermal insulation property of cold protective clothing.Firstly,comparing the performance difference between the new and traditional types of wadding,the coffee carbon fiber with excellent comfortable performance was selected by using the fuzzy mathematics comprehensive evaluation method.Then the relationship between the filling density of the test bag and the thermal insulation property of the wadding was preliminarily explored.Based on the conclusion of test bags,this paper made different filling density of cold protective clothing,through the real dressing experiment,testing the static and motion state of various parts of cold protective clothing surface temperature,the average skin temperature of human body,heart rate,and combining the subjective evaluation,the relationship between the filling density and thermal insulation property of cold protective clothing was explored.Finally,cold protective clothing with different ease allowance were made,and the relationship between the air gap and the thermal insulation property was explored by using infrared thermal imaging technology,three-dimensional scanning technology and combining with the subjective evaluation.The main research contents and conclusions of this paper are as follows:(1)Through market research and literature review,five kinds of new types of wadding and four kinds of traditional types of wadding as experimental object were tested,including thermal insulation property,fluffiness,compression recovery property,softness,the temperature rise of far-infrared radiation property,and air permeability property.To establish fuzzy comprehensive evaluation model,the combination weighting method was used to calculate weight,and the order of wearing comfort properties of nine kinds of wadding was obtained.The results showed that the coffee carbon fiber wadding has the best comfort,which is superior to 90%down and others,and can be used as the first choice of wadding for cold protective clothing.(2)In order to explore the relationship between filling density and thermal insulation property of coffee carbon fiber wadding preliminarily,the seven test bag with filling density range 60g/m~2from 240g/m~2and the gradient of 30g/m~2was made to analyze the relationship between filling density and the thermal insulation property.The results show that:When the filling density are 60g/m~2～210g/m~2,the thermal insulation property of the test bag increases with the increase of filling density,and when the filling density are 210g/m~2～240g/m~2,the thermal insulation property of the test bag starts to drop.The regression equation between filling density and the thermal insulation property of the test bag is established.(3)When cold protective clothing filled with 120,150,180,210,240g/m~2coffee carbon fiber wadding,there are significant differences in the thermal insulation property and comfort of cold protective clothing with different filling densities(P<0.05).In the static and motion state,the thermal insulation property and comfort of the cold protective clothing both increase first and then decrease with the increase of the filling density.The thermal insulation property and comfort of cold protective clothing with the filling density of 180g/m~2is relatively good,and 120g/m~2is relatively poor.Comparing the better filling density of the test bag and the cold protective clothing,the better filling density of the test bag is 210g/m~2,and the cold protective clothing is180g/m~2.The difference between them is analyzed by the human body-clothing heat transfer model and the heat dissipation mechanism of the test bag.It shows that there is a certain error in using test bag to measure the optimal filling density of the wadding to predict the cold protective clothing.(4)Through three-dimensional scanning technology and Geomagic Wrap software,the average thickness and total volume of the air gap under the five different ease allowance of cold protective clothing are obtained,which are 25.22mm～42.25mm and17.51dm~3～31.50dm~3.As the amount of ease allowance increases,the air gap shows an increasing trend,but the growth rate gradually decreases.The changes of the average thickness and total volume of the air gap are similar.The regression equation between bust looseness and air gap is established.(5)Different ease allowance have significant differences in the thermal insulation property and comfort of cold protective clothing(P<0.05).In the static and motion state,with the increase of the ease allowance,both the thermal insulation property and comfort of the cold protective clothing increase first and then decrease,indicating that there is a critical ease allowance of the air gap on the thermal insulation property and comfort of the cold protective clothing.When the average air gap thickness is25.22mm～34.13mm and the total air gap volume is 17.51dm~3～24.74dm~3,the thermal insulation property and comfort of the clothing show an upward trend.When the average air gap thickness is 34.13mm～42.25mm and the total air gap volume is24.74dm~3～31.50dm~3,the thermal insulation property and comfort of the clothing show a decreasing trend.The regression equation for bust looseness,air gap and the thermal insulation property of the cold protective clothing.(6)Within the scope of the experimental design in this paper,for short H-type men’s cold protective clothing of 170/88A size,under the premise of satisfying the basic daily exercise ease allowance,the bust looseness is 26cm,the average air gap thickness is 34.13mm,and the total air gap volume is 24.74dm~3,the thermal insulation property of the cold protective clothing can reach a good state.It can also better play the role of coffee carbon fiber wadding.The research in this paper can provide a theoretical basis for the thermal design,optimal configuration and scientific dressing of cold protective clothing,and provide a reference for the development of related cold protective clothing products for enterprises.