Influence Of Reinforcement Methods On The Directional Water-transfer Properties Of Carded Nonwoven Materials

Nonwoven materials possess many advantages which including short process flow,high speed and low cost of production and now were used in various fields widely.The phenomenon of directional water-transfer is widespread in nature.Nonwoven materials with directional water-transfer properties can realize one-way liquid conduction rapidly without back infiltration which benefits the material with some additional functions and its application fields also be broadening.At present,the research on the factors that influence the directional water-transfer properties of nonwoven materials were mostly focused on raw materials（fiber）,finishing processes,etc.Few scholars explored the influence of reinforcement methods.After the single fiber were carded into a web,the reinforcement process took place to endow the certain physical and mechanical properties in production process of nonwoven materials.The reinforcement method plays a decisive role in developing various properties of nonwoven materials.Hydrophilic ES fibers（PE/PET）and hydrophobic ES fibers（PE/PP）were raw materials used in this study,the two kinds of fibers were carded into a web respectively by the carding machine and then combined in parallel direction to form a composite web.Needle punching and thermal bonding technologies are used to reinforce the composite web which could endow the two layer of fiber web with good interface compatibility,and nonwoven materials in different reinforcement process got prepared.Testing the directional watertransfer properties of different materials and analyze the directional water-transfer principle.Changing the reinforcement methods to explore the influence of different reinforcement methods on nonwoven materials’ directional water-transfer properties.Testing some other properties of nonwoven materials with directional water-transfer properties and analyze the application.Compared with the traditional methods of producing directional water-transfer nonwoven materials by chemical finishing,the process used in this topic did not have any finishing reagent and process involved which possess the advantages of safe and pollutionfree,the materials were expected to be used in the medical and hygiene fields.By studying the preparation and properties of the cared ES fiber directional watertransfer nonwoven materials in different reinforcement methods,this topic draws the following conclusions:（1）Produced the needle-punching nonwoven materials.The materials constructed wetting gradient between three structures of the hydrophobic layer,the hydrophilichydrophobic cross layer and the hydrophilic layer to achieve directional water-transfer properties under the combined action of hydrostatic pressure,hydrophobic force and wetting force.The result of directional water-transfer properties test（camera observation method,dynamic contact angle,liquid moisture management ability test）confirmed that best process parameters of materials’ directional water-transfer properties are: density 100 g/m2,hydrophilic-hydrophobic fiber web ratio 1:1,and needle-punching frequency 400 r/min.（2）Produced the hot-rolling bonding nonwoven materials.The materials constructed wetting gradient between two structures of the hydrophobic layer and the hydrophilic layer and achieve the directional water-transfer properties under the combined action of hydrostatic pressure,hydrophobic force and wetting force.The result of directional water-transfer properties test（camera observation method,dynamic contact angle,liquid moisture management ability test）confirmed that the best process parameters of materials’ directional water-transfer properties are: hot-rolling temperature 130℃,hydrophilichydrophobic fiber mesh ratio 1:2,density 100 g/m2.The hot-air nonwoven materials were too thick and rough in hydrophobic surface to meet such properties.（3）The reinforcement process made a certain effect on the thickness,tensile properties,pore size,air and moisture permeability,capillary action,softness and directed water-conducting properties of the materials.Under the same density,the needle-punching materials were thicker than the hot-rolling materials,and the tensile breaking strength,pore size,air permeability,flexibility and liquid penetration time also better than the hot-rolling materials,but the anti-reversion ability is slightly worse than that of the hot-rolling material.The nonwoven materials properaed in this study are expected to be used in the field of medical and hygiene product.