Preparation And Thermal Protection Performance Research Of Anti-Molten Metal Spattering Composite Coated Fabrics

The presence of high-temperature molten metal throughout the entire production process in the metallurgical industry makes injuries caused by molten metal spattering the most typical occupational injury in the industry.Equipping staff with high-performance molten metal spatter protective clothing can effectively reduce the probability of injury during operation,but the clothing needs to have good heat insulation,flame retardancy,and effective protection against high-temperature liquid metal spatter represented by aluminum water and iron water.Traditional molten metal spattering protective fabrics are mainly thickened cotton fabric with flame retardant finishing,heavy canvas fabric,and aluminum coated fabric,etc.In actual use,when these protective fabrics are in the face of temperatures close to thousands of degrees Celsius and accompanied by a large number of infrared radiation of molten metal,there are molten metal easy to adheres to the surface of the fabric continuously exothermic,protective fabrics are not high-temperature resistant,the heat reflective layer of the fabric surface is easy to be melted and taking comfort poor,bulky,inconvenient movement after wearing and other problems,so the traditional protective clothing to play a more limited protective role.For the shortcomings of traditional metallurgical protective clothing,this paper developed an anti-molten metal spattering heat insulation coated fabric,which was coated with one or more kinds of heat insulation particles applied to the surface of the fabric to give the fabric good thermal insulation,flame retardant,and anti-molten metal spattering performance.Silica aerogel particle is a kind of nanoporous material with excellent performance,and the thermal conductivity at room temperature is only 0.013 W/（m·k）,which has a promising application in the field of heat insulation.However,near-infrared radiation at wavelengths of 3-8μm has strong penetration for silica aerogels in high-temperature environments,so the addition of an opacifier can be used to weaken the radiative heat transfer to improve the heat insulation performance of silica aerogels in medium and high temperature conditions.Potassium hexatitanate whisker（K₂O·6TiO₂,PTW）is an alternative high-performance opacifier material with very low thermal conductivity and high infrared reflectivity,and can withstand a high temperature of 1200℃;Its thermal conductivity at room temperature is only 0.089 W/（m·k）and has negative thermal conductivity,and there is also a good composite effect between potassium hexatitanate whisker and polymer.Therefore,this paper on the basis of the heat insulation performance of a single silica aerogel coated fabric,the potassium hexatitanate whisker was selected as an opacifier to be doped into the aerogel particles,and the silica aerogel/potassium hexatitanate whisker composite coated fabric was further prepared so that silica aerogel particles and potassium hexatitanate whisker were coated on the fabric surface as a mixed filler,which further enhanced the heat insulation performance of the coated fabric and improved the problem of high infrared transmittance of silica aerogel.The main findings of this paper were as follows:（1）The heat insulation performance of silica aerogel coated fabric was positively correlated with the content of the functional particles.When the content of aerogel particles was 7.5%,the coated fabric had the best heat insulation performance.The thermal conductivity was reduced by 15.9%compared with the original fabric,the light reflectivity of the coated fabric surface was up to 94%,and the temperature difference of the inner side of the fabric and the surface temperature of the fabric under the heat source irradiation was reduced by 16.8℃and 16.9℃,respectively,compared with the original fabric.（2）The doping of potassium hexatitanate whiskers and the reasonable interparticle ratio could further improve the heat insulation properties of the coated fabrics.With the increase of the ratio of silica aerogel in the composite coated fabric,the thermal conductivity of the coated fabric tended to decrease first and then increase,while the light reflection performance,and thermal radiation protection performance under heat source irradiation increased first and then decreased.When the ratio of silica aerogel to potassium hexatitanate whisker was 3:7,the thermal insulation performance of the composite coated fabric was the best,and the thermal conductivity was reduced by 19%compared with the original fabric;after irradiation by a heat source,the inner temperature difference and surface temperature of the composite coated fabric were reduced by 16.0℃and 19.4℃respectively compared with the original fabric,and the high infrared reflectivity of potassium hexatitanate whisker made the reflectivity of the composite coated fabric reach up to 99%.（3）250 g high-temperature aluminum solution was used to test the anti-molten metal splash performance of the coated fabric.It was found that the surface of the silica aerogel coated fabric with a particle ratio of 7.5%and the silica aerogel/potassium hexatitanate whisker composite coated fabric with a particle ratio of 3:7 was free of holes and no adhesion by residual metal.The appearance of the fabric was maintained well,and no burning occurred.The PVC film was not damaged.（4）The heat insulation coating finishing enhanced the friction resistance,breaking strength,and bending stiffness of the fabric,and the above properties tended to be gradually strengthened with the increase of the proportion of polyacrylate coating agent and functional particles.However,after coating finishing,the breathability and moisture permeability of the coated fabric decreased,and the decrease was greater with the increase of the proportion of polyacrylate and functional particles.