Test And Evaluation On Structure And Mechanical Properties Of Basalt-based Aramid Needle-punched Nonwovens

Recently, environmental pollution draws more and more attention which stimulated demandsof heat resistant fabrics in diverse fields, such as energy, traffic, aerospace, etc. Aramid fibers,Polytetrafluoroethene fibers are currently widely used, however, more research is paid on basaltfibers because of extraordinary mechanical property, chemical resistance, heat resistance.Surface morphology, mechanical properties, heat resistance and thermal stability of basaltfiber and its products were tested in high temperature, and compared with the production ofaramid fibers, PTFE fiber, and glass fiber. Results provided references to filtering materialprocessing and usage. The main research contents and conclusions were as follows:1. Structure and mechanical properties of basalt yarnsTM3000type of scanning electron microscope was used to observe the structure of yarnsbefore treatment, Hualong WDW-20type microcomputer control universal material testingmachine was used to test breaking strength, breaking elongation, elastic modulus and so on.As oberserved from yarns’ morphology, it can be conclude that surface of basalt yarn issmooth, suitable for filtering material, surface of the other two were smooth but not so good asbasalt fibers’. It can be concluded from the mechanical test, three yarns were sronger thanordinary material yarn. Highest rigidity and strength enables product of basalt less tendency ofdeformation.Collusion test indicated that the ratio strength of basalt yarn is lowest.2. Heat resistance of basalt yarnsThe DHG-9240type a thermostatic drum wind drying oven was used to heat the specimen,temperature is set to140℃,170℃,200℃,230℃,260℃, respectively, and treated time isset as3h,6h. After each treatment, morphology and tensile strength were tested. TG209F1wasused to test the starting decomposition temperature which determines thermal stability.As oberserved from yarns’ morphology, it can be conclude that surface of basalt yarn startedto damage from the230℃, time had little effect. Surface of PTFE amd aramid yarn started todamage after140℃, time works.It can be concluded from the mechanical test that the strength ofthe basalt yarn maintained the highest rate, elongation at break is the most stable, elastic modulusretention is low, collusion intensity residual rate is high. TG analysis reflects that initialdecomposition of basalt yarn is highest, higher than900℃.Structure and performance of basalt-based aramid needle-punched nonwoven materialTM3000type of scanning electron microscope was used to observe the structure of the yarn.Hualong WDW-20type microcomputer control universal material testing machine was used to test mechanical performance index of samples.Surface morphology of the nonwoven fabric showed a3-D mesh structure which is advantag-eous to filter material, fibers showed a smooth surface.Singeing damaged surface with holes.Strength and elongation of basalt aramid fiber needle-punched nonwoven cloth and glass fiberfabric basically met the national standard "fabric bag filter with bag technology conditions".Basalt aramid fiber needle-punched nonwoven material after folding has a better comprehensiveperformance among four fabrics.4. Heat resistance of basalt-based aramid needle-punched nonwoven materialDHG-9240type thermostatic drum wind drying oven was used to heat the samples under260℃, morphological and mechanical properties changes were tested. TG209F1was used toevaluate thermal stability.Treated under260℃for3h after processing, the surface of the structure found that, thesurface of the fabric structure damaged, and singeing surface damaged more seriously than theother,side. Tensile performance analysis found that the basalt strength retention and elongationretention of aramid fiber needle-punched nonwoven material reached100%, the modulus retentionreached88%.TG curve analysis found that the initial decomposition temperature of four fabrics ishigher than350℃, nonwoven fabric is better than that of glass fiber coated fabric. Basalt–basedaramid needle-punched nonwoven materials showed the least gravity loss at600℃.