Testing And Evaluating The Thermal Resistance Of Down Jacket

Down jacket because of its light,warm and other characteristics in the cold clothing market occupies an advantage.During my internship in a down-jacket factory,I found the warmth evaluations of the existing down jackets were conducted under standard conditions.However,the actual temperature and humidity changes will affect the thermal resistance of down jackets.The traditional idea is that the greater the amount of filling,the better the heat preservation.However,the“critical amount of filling”exists in the certain volume down liner measured by the experiment.There is a lack of quantitative research on the relationship between temperature,unit filling density and warmth retention of down jackets.Therefore,this paper takes the warmth retention of down jackets as the research object,and evaluates the warmth retention of down jackets through the market survey in East China,the thermal resistance test of down jackets,the design and manufacture of different warmth retention jackets,and the thermal resistance test of down jackets.The main contents and conclusions are as follows:(1)Market research on down jacketsThree popular down jacket brands in East China were selected and the sales market survey found that the filling volume of the popular down jacket was distributed in 40 g/m~2~160 g/m~2.The sales period of down jackets is mainly from November to January.Considering the climatic conditions in East China during this period,the test temperature of this subject is set to-6?~15?,the test humidity is set to 40%,and the wind speed is below 1m/s.The following survey on the wearing condition and habits of consumers of the three brands found that the main wearers are women aged 26 to 46,whose metabolic standard was 2MET(116.4w/m~2).Consumers generally mistakenly believe that down jackets with the same size have better warmth retention with a larger amount of filling.This paper verifies that for down jackets with a certain amount of filling,there exists a"critical amount of filling"for each temperature.In this case,as the amount of filling increases the heat resistance will no longer rise steadily.(2)Thermal resistance test of down liner sampleThe thermal resistance values of 13 samples were tested at 8 temperatures with HFB-1 fabric plane-board.By studying the influence of temperature and unit filling amount on the thermal resistance of down jacket liner,the change mechanism of the thermal insulation of down jacket liner was analyzed.The results showed that the thermal resistance of down liner samples with the same unit of filling volume decreased with the increase of temperature at-6~0?,and remained almost unchanged with the increase of temperature at 0~15?.At the same temperature,the thermal resistance of down liner samples increased with the increase of filling density.However,when the filling density increased to 120~130 g/m~2,the increase of thermal resistance was not significant,and when the filling density increased to 140 g/m~2,the thermal resistance of liner samples decreased slightly.The function equation of unit filling-temperature-thermal resistance in the temperature range of-6~15?is established.The change mechanism of the heat preservation of the down jacket liner is analyzed as follows:with the increase of unit filling amount,the distribution of down and heat dissipation mode of the liner change,and the main heat dissipation mode of the liner changes from heat convection to heat conduction between fibers.(3)Design and manufacture of down jacket sampleBased on preference survey in east China women down jacket and fit,selected 50,80,110,140 g/m~2 for down jacket sample unit filling,design down jacket for flat shoulder sleeve,length65cm,slightly H version of waist.6,8,10,12cm were used to quilting,spacing of the quilting before filling pile technology made 4 down jacket sample.(4)Evaluation of the warmness of down jacket sampleThe thermal resistance of 4 down jackets at-3,3 and 9 temperatures were tested by LD-1thermal manikin in the climate chamber.The results showed that the thermal resistance of both the surface air layer and the non-surface air layer decreased with the increase of temperature under the condition of the same filling amount at-3?~3?,and the two thermal resistance slightly increased with the increase of temperature at3-15?.Under the same temperature condition,the unit filling amount of down jacket sample ranged from 50g/m~2 to 140g/m~2,and the two thermal resistance showed a significant increase trend.The thermal resistance of down liner under the same condition was higher than that of down jacket.Taking underwear with thermal resistance of 0.8clo as the benchmark,the suitable temperature ranges for down jackets with the filling volume of 50,80,110 and 140g/m~2 are 9~12?,3~9?,0~6?and-6~-3?.