The Investigation Of Preparation Process And Properties Of Rigid Carbon Fiber Integrated Felt

Rigid carbon fiber integrated felt is a new type of high-temperature thermal insulation materials, which is widely used in national defense, steel industry, chemical industry and other industries. Especially with the rapid development of crystalline silicon industry, as the high-temperature furnace heat field insulation materials, the demand of high-quality rigid carbon fiber integrated felt reached an unprecedented heights, the research of rigid carbon fiber integrated felt is getting more and more significant. As we all know, the performance of the rigid carbon fiber integrated felt is not only related to its service life, but also related to the quality of the high-temperature furnace products. Therefore, how to get rigid carbon fiber integrated felt with high-quality performance has become a major common challenge of domestic and international carbon fiber felt manufacturers.At present, there are mainly three types of the preparation method of rigid carbon fiber integrated felt:the method of layer bonding layer under pressure; the method of vacuum molding; the method of needle-punching molding. The vast majority of traditional rigid carbon fiber integrated felt were prepared by the method of layer bonding layer under pressure, but the felt was low-quality with uniform density, bad integrity and unstable thermal field; Rigid carbon fiber integrated felt prepared by the method of vacuum molding had badly chalking phenomenon, which had limited its application scope; Needle-punching molding is a new preparation method of rigid carbon fiber integrated felt, the performance of its products is excellent with good integrity, which is possible to improve the shortcomings of traditional rigid carbon fiber integrated felt effectively, it has a broad development prospects.In this paper, the process of rigid carbon fiber integrated felt prepared by the method of needle-punching molding was described in detail. Effect of every process including needle punching parameters, impregnating solution concentration, carbonization and graphitization process on the density and hardness of rigid carbon fiber integrated felt were deeply studied and by the use of scanning electronic microscope, felt body morphology was observed to explore the distribution of the phenolic resin inside the rigid carbon fiber integrated felt. Through experimental measurements, the performance of rigid carbon fiber integrated felt prepared by different molding process was evaluated and the reasons for these differences were analyzed in detail. It is shown that:the needling density and the needling depth can affect the density of the preform, thus affect the final density of the rigid carbon fiber integrated felt; The concentration of impregnating solution determines the quality of the thermosetting phenol resin inhaled in the soft carbon fiber integrated felt, which improves the quality of the carbon fiber felt leading to affect its final density; Carbonation and graphitization temperature affect the degree of the removal of impurities in the rigid carbon fiber integrated felt which is an important factor to affect the final density, hardness, carbon content and ash content of the rigid carbon fiber integrated felt.Analyzed by comparative evaluation, the differences of performance of the rigid carbon fiber integrated felt prepared by three different molding methods were mainly due to the molding, auxiliary materials accession and post-treatment process.