Study On Thermal Protection And Comprehensive Evaluation Of Comfort Of Multi-layer Fabrics For Firefighter-Clothing

The firefighters'protective clothing is the most important equipment for firefighters to fight and rescue disasters.Its performance directly determines the firefighter's work efficiency and life safety.Therefore,it is necessary to strengthen the research on comfortable performance while paying attention to the thermal protective performance of firefighting clothing.The thesis takes thermal protective and comfortable performance as the starting point,from outer shell,moisture barrier,thermal barrier and comfort lining to the four-layer fabric combination,realizes in-depth research from single layer to multilayer.The thermal protective and comfortable performance of outer shell and fabric combination were evaluated by the index Ci based on MATLAB calculation program.At the same time,in order to improve the thermal protective effect and thermal moisture comfort of the fabric composite system,the anti-thermal radiation layer is introduced on the basis of the four-layer combination to explore the influence of the position of the anti-thermal radiation layer and the hole rate on the comprehensive performance of the combined system.This topic selects 8 outer shell,2 moisture barrier,1 thermal barrier and 1 comfort lining.The outer shell is mainly composed of aramid 1313 and aramid 1414 blended fabric,and the moisture barrier is aramid 1313/1414 blended non-woven fabric+PTFE membrane,the thermal barrier is made of aramid non-woven fabric and aramid/flame-retardant viscose blended base fabric.It is tested and studied for their thermal protective and comfortable performance.The main conclusions are as follows:(1)For single-layer fabrics,the test results of mechanical properties,flame-retardant properties and moisture permeability of each layer of fabrics meet the requirements of the industry standard,which can be used for fire-fighting clothing structures composition.The thermal performance and comfort performance of the outer fabrics were comprehensively evaluated,andtheoverallperformanceoftheouterfabricwasasfollows:A5>A7>A8>A2>A3>A1>A6>A4.At the same time,the correlation coefficient between the weight of the outer fabric and the breaking strength,thermal resistance and moisture resistance was 0.487,0.252 and 0.516,and there was a positive correlation.(2)The correlation coefficient between the surface density and the damage length of the flame retardant property and the permeability of the fabric There is a negative correlation between-0.564 and-0.509,respectively.(3)The thermal protective performance(TPP)of the eight fabric combinations is S2>S5>S3>S7>S4>S8>S1>S6.Extracting the three-dimensional eigenvalue of the heat shrinkage of the outer fabric,The correlation coefficient between the heat shrinkage rate and the shrinkage height of the outer fabric and the TPP value of the overall fabric combination is-0.610and 0.401,respectively,that is,the more severe the heat shrinkage of the outer fabric in the fabric combination,the more the TPP value of the overall combination is low.The THL is S1>S5>S7>S3>S4>S8>S6>S2 from large to small.The measured thermal resistance(y)of the fabric combination can be expressed linearly by the sum of the thermal resistance of each single layer fabric(x),and the regression equation is y=-0.00322+0.97792x.Through multiple regression analysis,the clo and WVT of the fabric combination can independently represent the total heat loss of the fabric combination.The multiple linear regression equation is Qt=162.9-147.263K+0.342W.(4)The TPP value,heat shrinkage rate and total heat loss were used as the evaluation indexes for the eight fabric combinations.The comprehensive performance of the combination was S2>S5>S3>S7>S4>S1>S8>S6,and fuzzy clustering analysis was used.It is found that when k=0.9044,the fabric combination is divided into two categories:{S1,S2,S3,S5,S7,S8},{S4,S6},and the clustering result is consistent with the actual situation.(5)the experiment shows that the optimal position of the anti-heat radiation layer is between the outer shell and the moisture barrier,and the combined system has the best thermal protection effect at this time.When the porosity of the anti-thermal radiation layer is 26/cm~2,the heat-moisture comfort of the fabric combination is the best.When the porosity of the anti-heat radiation layer was 26/cm~2,the overall performance of the fabric combination was the best,which was superior to the original fabric combination.