| With the improvement of living standards,modern people put forward higher requirements for the thermal and wet comfort of textiles.Because of its unidirectional moisture conduction effect,unidirectional moisture conduction fabrics can significantly improve the thermal and wet comfort of fabrics.A large number of researches on unidirectional moisture conduction woven fabrics and knitted fabrics have emerged,but the researches on unidirectional moisture conduction nonwovens are still lessThis paper focuses on the unidirectional moisture conducting needle punched composite.Four kinds of single-layer fiber networks were prepared with viscose fiber,fine denier polyester fiber,cross-section polyester fiber and super absorbent polyester fiber as raw materials.Then,needle punched composite of cross-section polyester/super absorbent polyester with different weight was prepared with needle punched processing method respectively,which is different from the polyester/viscose composite with different overlapping methods.There are two groups of needle punched composite with unidirectional moisture conductivity.By comparing the moisture absorption performance of single-layer fiber networks with that of needle punched composite,the moisture content change,the soaking time of fiber net,the diffusion rate of liquid water and the water absorption rate,the basic moisture transfer in composite fiber net was studied.By analyzing the diffusion of water in the horizontal direction of polyester needle punched composite measured by M290 liquid water tester,and observing the diffusion of water in the composite fiber net by hand dripping,the transmission mechanism of water in the needle punched composite was analyzed.Finally,through the application in the field of taking,the two transmission paths of water in the needle punched composite are explained in detail,which proves the feasibility of the application of the needle punched composite in the field of taking.The main conclusions are as follows:(1)Two kinds of fibers with wetting gradient are arranged on both sides of the double-layer needled composite fiber net due to needle punched process.When the needle punched composite absorbs water,the water content of the fiber layer with good hygroscopicity is always greater than that of the fiber layer with poor hygroscopicity,that is to say,the water content in the needle punched composite tends to the high hygroscopicity fiber layer.The direction of water transfer is obvious(2)The weight of the single-layer fiber networks has little effect on the one-way moisture conduction of the composite fiber net,which only affects the maximum moisture content on both sides of the sample and does not change the direction of moisture transfer.When the weight of cross-section pet single-layer fiber network increased from 70g/m2 to 100g/m2,the maximum water content of both sides decreased,which was related to the direction of water dripping during the test.(3)The diffusion of water in the polyester/viscose needle punched composite has obvious selectivity.Water only diffuses in the viscose fiber layer or the moisture conducting channel composed of viscose fiber.Because of the obvious difference of moisture absorption between the two fibers,the water absorption boundary between the viscose fiber layer and the polyester fiber layer is obvious.(4)When two kinds of single-layer fiber networks with different water absorption properties are compounded by needling process,the direction of needle punched process will cause the interlaminar transfer of the fibers,and ultimately have a great impact on the one-way moisture conductivity of the composite fiber nets.The composite fiber network,which is made by feeding the fibers with poor Hygroscopicity on the fibers with good hygroscopicity into the main thorn mechanism,has better one-way moisture conductivity.The average moisture transfer index of the two-layer needle punched polyester/viscose composite fiber mesh is 236.42 and 311.25 respectively,without changing other process parameters and only changing the direction of lamination,which shows great difference in unidirectional moisture conductivity.(5)The choice of fiber material has a great influence on the final one-way moisture conduction effect of needle punched composite.When the fiber mesh with good hygroscopicity is on the top and the fiber mesh with poor hygroscopicity is on the bottom,the moisture content,liquid water diffusion rate and water absorption rate of polyester layer of polyester/viscose needled composite fiber net are all 0,which means the polyester/viscose needle punched composite has ideal one-way moisture conduction performance.However,the difference between the two side fibers of the polyester composite fiber mesh with cross-section polyester fiber and high hygroscopicity polyester fiber is not enough to achieve ideal one-way moisture conduction through the structural design method Effect.The horizontal diffusion rate of moisture on one side of cross-section polyester layer with poor hygroscopicity is 0.40-1.88,and the water absorption rate is 6.66-13.72,that is to say,the cross-section polyester layer still has moisture diffusion,and the one-way moisture conduction effect is not ideal.(6)When the unidirectional moisture conducting needle punched composite is applied to the close fitting wear fabrics,the nonwovens composed of two kinds of fiber nets with different moisture absorption properties can discharge the sweat of the human body outwards and the external water to a certain extent by taking the viscose fiber layer with high moisture absorption as the side close to the external environment and the polyester fiber net with low moisture absorption as the side close to the human body.The utility model has the function of isolating from the human body and has the better one-way moisture conducting ability.When the needling direction is from the inner polyester fiber layer to the outer viscose fiber layer,the one-way moisture conduction ability of the composite fiber network can be further improved. |
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