Technical Research On Three-dimensional Tubular Carbon Fabrics In Circular Orbit Weaving

With the demand for lightweight high-strength composite materials growing,three-dimensional textile composite materials have been rapidly developed.Carbon composite materials have low density,high strength,high temperature,and,the price gradually reduced with improving weaving technology.Use of the three-dimensional tubular fabric as a composite of reinforcing material presents lots of advantages,including light weight,high specific stiffness and specific strength,fatigue resistance and other characteristics.Thus,the 3D tubular fabric based reinforcing composites have been got more and more acceptation.Circular weaving method is a new type of three-dimensional tubular fabric weaving technology.Using circumferential opening,radial shedding,axial beating-up,the method can achieve continuous weaving process.At present,the research about circular orbit weaving method is at an initial stage,and the 3D fabrics with polyester have been successfully woven,which verified the feasibility and variety of circular orbit weaving.However,the existing three-dimensional tubular loom and weaving methods have some shortcomings,especially it is urgent to explore the ability to adapt to weaving of carbon fiber.The technical research of 3D carbon tubular fabrics in circular orbit weaving was studied through design of different weave structures,weaving process of 3D carbon tubular fabrics,and analysis of off-loom fabric,fabric finishing and performance testing in this paper.Firstly,this thesis briefly introduced the circular orbit weaving method,carbon fiber composite and commonly used weaving structure of 3D tubular woven fabrics,and mainly presented design of different weft insertion methods,and then identified the basic structural parameters suitable for carbon fabric weaving For the same kind of structure,the design of different weft insertion methods resulted in different weaving processes.The number of operators,the number of weft conveyors carried by each operator and the number of different openings in each operator are important factors,influencing the efficiency and error rate of carbon manual weaving.Then,a new circular orbit loom prototype was designed and formed with increased the number of turns from 10 to 20.Also,on the new loom,a dark track was used to replace the out track,and internal slider was used to replace the external slider.Take the joint organization as an example,the study selected many operators responsible for 20 laps orbit each with the same number of different openings in each operator,accompanying with water and other assistant operations for the machine weaving,and successfully completed polyester/carbon fabrics weaving and fully carbon fabrics weaving with joint junction structures.The number of round tracks ensured the thickness of the fabric requirements;The replacement of tracks and slider improved,as much as possible to reduce the friction and collision in the weaving process of carbon fiber and avoid its fuzz and fracture;Thechoice of the joint structures and weft insertion methods could further reduce the damage of carbon fiber in weaving,and ensure high efficiency and low error rate of manual operation of carbon 3D tubular fabric weaving.After the fabric was weaved,the appearance and surface condition of the fabric were measured and analyzed.The samples were well formed and the appearances were smooth without defects.The thickness of the fabrics meets the design requirement.twill pattern on fabric surface looks consistent with the surface layer of the joint structure.The correctness and practicability of the mode selection are good.At last,fabric finishing and performance testing were made to collect and analysis the surface morphology of composited fabrics on digital equipment.the weaving process of three-dimensional tubular carbon fabrics studied in the research is reasonable,and provides technical supports to further development of automated circular orbital weaving of carbon fabrics.