Study On Raw Materials And Simulation Of Spinneret Holes For Nonwovens With Vein Imitation

In recent years,the technology of melt blowout nonwovens based on petroleum has developed rapidly at home and abroad,and the application field of melt blowout nonwovens is more and more extensive.However,with the rapid development of industry and the contradiction of strengthening environmental protection,nonwovens based on petroleum as raw materials are widely used.Waste,due to its non-degradation,will cause environmental problems.Biodegradable and environment-friendly melt-blown materials have become current research hotspots.In this paper,a sort of corn straw husk cellulose/NMMO·H₂O solution was studied as raw material for nonwovens.On this basis,the application of the bionic engineering principle in nonwoven technology is explored,and the superhydrophobic bionic prototype is extensively studied to obtain the theoretical basis for the development of hydrophobic surfaces.However,the complexity of the traditional superabsorbent bionic technology and the poor water absorption effect hinder the further application and development of superabsorbent bionic materials.In this paper,an assortment of spinneret with special structures（the structure mainly mimics the leaf vein structure of plants）micropores is designed and a cellulose-based nonwoven fabric with superabsorbent is prepared.The point of view and the main contents are as follow:（1）In this paper,the cellulose pulp of corn straw husk with excellent properties was prepared,and its dissolution in NMMO was studied.The optimal dissolution conditions ofthe pulp were initially revealed,and the change of cellulose structure during the dissolution process was deeply studied,which is of great significance for the preparation of cellulose-soluble spray nonwovens with better properties.The prepared corn straw hulls cellulose/NMMO·H₂O solution is a common tangential force thinning fluid.The experimental results showed that the cellulose content and the degree of pulp polymerization had a great influence on the obvious viscosity of the solution.More high the cellulose content and the degree of pulp polymerization,more high the distinct viscosity of the solution.（2）The role,position,and shape distribution of veins in leaves are summarized in detail,to better serve for the subsequent design of imitation veins spinneret.At the same time,a comprehensive introduction to the components of spinneret,analysis of the structure of each place,reasonable design and control of its structure,can achieve different fiber shapes,distribution,and tensile degrees,and then obtain different properties of nonwovens.A spinneret was designed with pilot holes and microholes,and the micro holes contained a main hole to mark the petiole,as well as four auxiliary holes designed concentrically with the main hole,and the auxiliary holes to mark the vein structure.The arrangement of the pilot holes and microholes was similar to the arrangement of the leaf veins of plants.The technical route of preparing the imitation vein nonwovens and the final model of the imitation vein nonwovens were proposed.（3）The bionic vein structure of spinneret hole was designed using the three-dimensional software Creo,and the flow behavior of cellulose/NMMO·H₂O solution was simulated under different convergence angles of spinneret plate and various channel length-diameter ratios of spinneret hole using POLYFLOW software.By fixing the length-diameter ratio of the spinneret flow channel and changing the convergence Angle of the spinneret plate,analyzing the solution flow of distribution of velocity field,shear field,and pressure field.The convergence Angle of the spinneret was fixed,the length-diameter ratio of the spinneret channel was changed,and the distribution of velocity field,shear field,and pressure field of solution flow were analyzed.After optimization,the spinneret with micro-pores of biomimetic vein structure was fabricated by electric discharge machining,and the spinneret was applied in the process of melt spray nonwovens.The spinning assembly of spinneret with micro-pores of biomimetic vein structure has preliminarily reached the condition of processing corn straw peel cellulose/NMMO·H₂O solution with a certain viscosity,and can prepare soluble spray nonwovens suitable for application in related fields.