Study On The Dispersion Characteristics Of Aramid Fiber And Aramid Fiber Paper

Due to the properties of aramid fiber,such as high strength and high modulus,it has been applied in various fields,such as wear resistant components of high-speed rail.Due to the high strength and flame retardancy of aramid fibers,it has been used to prepare special functional paper in papermaking industry.The aramid fiber is long,easy to flocculate,not easy to disperse,forming uneven and so on.This leads to the aramid fiber into paper uniformity,tensile strength and other properties are not ideal.In this paper,the influence of pretreatment on the dispersion effect of aramid fiber system and the production of aramid fiber paper were studied.In this paper,aramid staple fiber and aramid pulp fiber were pretreated respectively to study the effect of their dispersion.The pretreatment of aramid staple fiber was treated by dip washing,ultrasonic and beating.The pretreatment of aramid pulp fiber was treated by ultrasonic and beating.For the pretreatment of aramid staple fiber,the best method for immersion washing was to dip the aramid staple fiber with sodium dodecyl benzene sulfonate(SDBS)hot solution,and the dispersion of aramid staple fiber increased by 45.2%after washing.The optimal condition for ultrasonic processing is 9 minutes of ultrasonic time and 125 watts of ultrasonic power.In the process of beating,it is difficult for the aramid staple fiber to be beaten normally in PFI mill.In the process of beating,the dispersion of the aramid staple fiber will also be affected due to the filamentation and cutting of the fiber in the process of beating by the Valley beater.The best dispersion effect is beating for 30 minutes,and the dispersion of aramid staple fiber is increased by 10.3%.For the pretreatment of aramid pulp fibers,The optimal condition for ultrasonic processing is 9 minutes of ultrasonic time and 125 watts of ultrasonic power.During the pulping process,the friction tear of the fiber is the main factor in PFI mill,which results in little change in the average length of the pulping fiber in PFI mill,and it is difficult for the beating degree to increase in the later stage of pulping.The beating of Valley beater is mainly to cut off the fiber,resulting in a large change in the average length of the fiber and a gradual increase in the beating degree of the fiber.In this paper,the research on aramid fiber paper production includes:research on hot pressing process of aramid fiber paper,and the study on the conversion of dfibizer and the ratio of slurry of aramid fiber paper making,and the study on the influence of PEO dosage and dispersion revolution on aramid fiber paper,and the study on aramid fiber paper production by beating aramid fiber staple fiber.The hot pressing process is an important part of the aramid fiber paper production.The hot pressing process can improve the smoothness and compactness of the paper surface,which is conducive to the combination of aramid fiber.In this paper,the optimal hot pressing process conditions are that the hot pressing temperature is 260? and the pressure is 18 MPa,and the number of times is 2 and the time of each hot pressing is 15 seconds.The optimal ratio of raw materials and the dredges revolution of raw materials can make the raw materials better combined.The optimal dredges revolution of aramid staple fiber is 15000r,and the optimal dredges revolution of aramid pulp fiber is 5000r,and the optimal sizing ratio is the ratio of aramid staple fiber to aramid pulp fiber is 3:7.The addition of PEO can greatly improve the dispersing effect of aramide fiber system,thus affecting the performance of the paper.When the amount of PEO is 0.5%and the number of dispersing revolutions of PEO is 3000r,the dispersing effect of aramide fiber system and the physical performance of the paper are the best.The compactness of aramide fiber paper is 0.72g/cm3,and the tensile index is 7.36N·m/g,and the elongation is 0.46%.After the beating treatment,the aramid staple fiber becomes shorter and the surface is divided into wire brushwork,which affects the performance of the paper.When the beating time was 30 minutes,the elongation of aramid fiber paper increased by 36.7%and the tensile index increased by 9.8%.