Characteristics Of New Alumina Fibers And Fabrication Technology Of Fiber Textiles

Alumina fiber has the advantages of light weight,chemical resistance,high temperature resistance,good thermal stability,low thermal conductivity,etc.At the same time,it also has the characteristics of low raw material cost,simple production process,etc.It has high cost performance and commercial value.In this paper,on the basis of testing the morphological structure and composition,physical properties and chemical resistance of a new alumina fiber(provided by Shanghai Silicate Research Institute)independently developed in China,the molding process of alumina fiber textiles was studied.The suitable textile forming process was obtained,and the optimal molding process was obtained through single factor test and orthogonal test.The main work of this paper is as follows:Firstly,the thesis tested the morphological structure and composition,physical properties and chemical resistance of alumina fibers.It was obtained that the alumina fibers were arranged neatly,the length range was 100-200 mm and the length uniformity was not satisfying.The fiber fineness was 0.90 dtex and the finer distribution was evenly distributed.The result of XRD and IR spectra showed that the main components of alumina fiber were Al2O3 and Si O2.The Al2O3 crystal was rAl2O3 and the crystallinity was 59.2%.The main structure of alumina fiber was similar to the main structure of the current alumina fiber cotton.The alumina fiber has an initial modulus of 63.98 GPa and a breaking strength of 2.85 GPa,which has high-strength and high-modulus.Alumina fibers have extremely low hook strength and poor fiber bending resistance.By using a yarn twist meter to simulate the fiber twisting process,it is shown that the number of torsion twists of the alumina fiber was 23.5 revolutions/50 mm.The torsion properties of the fiber was poor.The moisture regain of alumina fiber was 0.29%,the specific resistance was 3.5×1010Ω·g/cm2,and the static/dynamic friction coefficient of fiber and metal was 0.1251/0.1189.Alumina fibers were treated with H2SO4 solution with a concentration of 3.0mol/L.The rate of fiber weight loss was 19.9% and the rate of strength loss was 26.34%.Alumina fibers treated with a concentration of 6.0mol/L Na OH solution had a rate of fiber weight loss of 18.2% and the rate of strength loss was 20.28%.The SEM test of the surface of the fiber treated with H2SO4 and Na OH showed that no obvious damage on the surface of the fiber,it is indicated that the alumina fiber has better acid and alkaline resistance than other inorganic fibers.Secondly,the forming process of alumina fiber textiles were explored.Alumina fibers were spun on cotton spinning equipment.After testing,when the ratio of alumina fiber/cotton fiber was 40/60,it reaches the best mixing ratio.Carding in best mixing ratio,after the drawing process and the slivers.After the spinning of the hollow spindle spinning machine,it was concluded that the alumina fiber could not be formed with the method of the traditional short fiber spinning process.The non-woven process of alumina fibers was investigated,and the carded and formed webs were reinforced by needling and chemical bonding.After testing,it was concluded that acupuncture can not play a role in reinforcing the web.Therefore,my current research adopted high-temperature binder to reinforce the web and obtains alumina fiber textile under a certain preparation process.Finally,the single factor test and orthogonal test were used to analyze the optimum process for preparing alumina fiber textiles.The binder concentration,soaking time,drying temperature and drying time are the experimental factors,and the thermal conductivity and bending strengths of alumina fiber textiles coefficient were test indicators.The range of each experimental factor was obtained by a single factor test: the binder concentration was 33.3-50wt%,the soaking time was 5-15 min,the drying temperature was 180-220°C,and the drying time was 1.5-2.5h.On this basis,by using the four-factor three-level orthogonal test method,obtaineing the primary and secondary order of the experimental factors.,which from high to low,are binder concentration: binder concentration > soaking time > drying time > drying temperature.The optimal preparation process was 33.3wt% binder concentration,10 min soaking time,185°C drying temperature,2.5h drying time.At this time the thermal conductivity of alumina fiber textiles was 148W/m·°C ?10-3 and 771 Pa bending strength.