基于相變熱耗散和熱絕緣的多功能層合防火織物制備和表征.pdf

1、Heat barriers or insulators were defined as those materials or combinations of materials,which retarded the heat transfer with reasonable effectiveness under ordinary conditions.Insulating materials were used in many dif

2、ferent applications and at a variety of temeratures.Thepurpose of thermal protective clothing is to reduce the rate of heat build up in human skin, in orderto provide time for the wearers to react, and avoid or minimize

3、skin burn injuries.This isaccomplished by using a garment which is both flame resistant and thermally insulating.Many ofthe heat barrier materials being employed use some form of textile fibers or fabrics.Firefighting

4、>　　protective clothing is a highly advanced system designed to protect people against being burnedin high temperature environments.This research focuses on the development and evaluation offirefighting fabrics use in fla

5、sh-over temperature approximately 1000℃.
　　The overall design of the isolated flexible composite fabric was compounded of innercomfort layer, phase changes endothermic composite layer and outside heat reflecting layer

6、,sequentially, in order to achieve a flexible, efficient, long-term effect of thermal protection.To give a brief introduction to the preparation and process of the flexible composite fabric, the high temperature environm

7、ent, severe heat, the fire incident due to radiation intensity, and relativelyhigh temperature thermal properties of the fibers were considered.
　　Metal foil has a high thermal the reflectivity and low cost-effective;

8、 therefore aluminum foil was used as a heat-reflective material, bonded to a high-temperature glass fabric.The nonwoven basalt fiber and nonwoven glass fiber fabric were selected due to their high performance under high

9、temperature environment.Two stages of phase change materials were selected to design the flexible composite fabric.The Galactitol was chosen as the first stage phase change material and NaCl-MgCl2 as the second stage pha

10、se change material in the composite fabric.The design principle considers some parameter such as phase change material phase change before and
　　after the relatively fixed, the choice of the high temperature resistant

11、 fibers needled felt and phase change as the endothermic composite layer matrix.The firefighting composite fabric substrate on
　　the outer layer heat-reflective layer, selection of high performance fiber, based on two

12、 phase change materials which are safe to use and easy to get.In order to ensure human comfort, the retardant cotton fabric was selected as the inner layer.To ensure the composite fabric flexibility,as well as the phase

13、change material is relatively fixed, the sewing processing of each of thefunctional structural layers of composite was formed.
　　To characterize the fabric insulation performance under the flash-over conditions and it

14、sprolonged failure behavior, fabric samples were placed in this environment, and the temperaturesensors were used to measure the specimens' positive and negative temperature changes with thetime.The temperature-time curv

15、es were obtained through computer control software for real-timerecording, to measure and compare the pros and cons of the firefighting fabric's insulationperformance.In addition, repeated exposure to open flame fire env

16、ironment fabric thermalprotective performance and retention of the basic mechanical properties test analysis.
　　The obtained composite fabric having excellent fire insulation properties, the compositefabric composed o

17、f functional decomposition due to their respective monolayer sharing role.Thisfabric design has a better fire insulation effect by the test of fire insulation performance of theflexible composite fabric.
　　From the an

18、alysis of the heat transfer model and the measured results of the fire insulationperformance, it is shown that the treated firefighting fabrics under the environment of hightemperature and severe heat, is difficult to ac

19、hieve long time protection.The high temperaturephase change materials during the fire exposure experiment and it is efficiency play significantrole in the fire protective performance of the composite fabric.The adiabatic

20、 test system heattransfer model in fabric thermal performance parameters vary with temperature of the heat transfermechanism needs to be further explored.So long, high-temperature differential drop firefightingfabric dev