Study On The Fabrication Of SiO₂ Aerogel/fiber Composite Insulation Packing Material And Insulation Mechanism

With the rapid development of national economy and national defence industry,the industries of electron,chemical engineering,medicine and food.etc.have more requirements for packing material.A kind of thermal insulation materials with low density,low thermal conductivity and certain structural strength attracted attention.This paper based on the structural design of thermal insulation material with low density,the design of material systems and the design of molding technology,and used aluminum silicate fibers and basalt fibers as skeleton material,SiO2 aerogel as main thermal insulation material,silica sol and sodium silicate aqueous solution as adhesive,finally a new thermal insulation packing material with innovation,low density and thermal insulation had been prepared by the centrifuge process at high speed and mould pressing and its thermal insulation mechanism has been studied systematically.The composition and microstructure of SiO2 aerogel/fibers composite material with nano pores was investigated by the means of SEM and Coefficient of thermal conductivity measuring instrument.Author focused on the study of the effect of SiO2 aerogel content,types of inorganic fieres and the density of composite material on the thermal insulation property.A simulation experiment on the material thermal conduction had been done to investigate the thermal insulation mechanism and prepared a light thermal insulation box with the size of 110mm×110mm×120mm,whose thermal insulation property and strength had been tested and evaluated.Study results shown the thermal insulation performance of SiO2 aerogel/basalt fibers composite material was superior to that of SiO2 aerogel/aluminium silicate fibers composite material.The thermal insulation property of SiO2 aerogel/basalt fibers composite material was excellent when thermal conductivity range and density was 0.010-0.030 W/(m-K)and 0.10-0.40g/cm3,respectively.The thermal conduction prediction model has been built and ensued the main thermal conduction pattern was radiation.Author also analyzed the effect of material thickness and the porosity on the thermal conduction and revealed its thermal insulation mechanism.A thermal insulation structure with the size of 110mm×110mm×120mm was prepared by using the SiO2 aerogel/fibers composite material and multi-wall corrugated board as surface layer and structural reinforced layer,respectively.The mechanical property and thermal property has been tested and the results shown the packing box of SiO2 aerogel/basalt fibers composite material reached the quality requirements.This study extended the application of SiO2 aerogel and basalt fibers,enriched the packing material system and builded the technology and theory based on the SiO2 aerogel/fibers material system,the study results had a certain theoretical significance and value of engineering application.