Mechanical Properties Of Spun-Thermal-Bonded Nonwoven Materials By Finlte Element Analysis

Spun-thermal-bonded nonwoven materials, which fibers are spun-fibers, are bonded together by thermally. Its products have rapidly developed in the market because it has the advantages of low cost, good performance, use of broad, etc. These are widely used in filter mask, surgical suit, sanitary napkin, baby diapers, adult incontinence pads, etc., in addition to a large number of applied in cable motor insulation materials, battery diaphragm, packaging materials, clothing lining, luggage lining, Coating Substrates and so on.When these are applied in the field of medical and health, which is surgical suit, sanitary napkin, baby diapers and adult incontinence pads, the nonwoven materials must ensure its breathability and tear strength. When these are used in cable motor insulation materials, battery diaphragm。 packaging materials, clothing lining, luggage lining and Coating Substrates, the non-woven materials must to have good isotropic strength, so the mechanical properties of nonwoven material has a great influence on their products performance.In this paper, using spun-thermal-bonded nonwoven material is a sample. Under the same scene, many layers multi-focus image (75layers) are shot by the optical microscope of the computer-aided microscope system, using image fusion algorithm, multi-focus image fusion of spun-thermal-bonded nonwoven materials are obtained. On the multi-focus image fusion of the sample, using post-processing of the denoising processing, edge detection, image segmentation and refinement, we can obtain clear multi-focus image fusion of the sample. The fiber fineness and bonded points size and spacing bonded points area, the material orientation, fiber and bonded points positional information were measured on clear multi-focus image fusion of the sample.In order to study the nonwoven materials anisotropy and relationship between fracture stress and fiber orientation distribution, the sample were clipped from the nonwoven materials to15degrees as a unit value, and12copies of each nonwoven materials, each copy taken three samples, Mechanical tensile test on YG065H Electronic Fabric Strength Tester and homemade simple stretching equipment.Through python language using positional information of fibers and bond points, compiling the subroutine, which can be read by ABAQUS, the finite element model of the geometric structure of nonwoven materials were rebuild in ABAQUS.In the finite element model, contrasting simulated stress-strain curves under different parameters of the viscoelastic material of bond points, the results showed that in the initial period of the mechanical tensile, plastic parameter of the thermal bonding points has8.1percent effect on the mechanical properties of the whole material, the bond points can be regarded as an elastic body.In the finite element model, contrasting simulated stress-strain curves under different parameters of the viscoelastic material of fibers, the results showed that When strain is39.8percent, the mechanical properties of fibers has30.9percent effect impact on mechanical properties of the whole materials, regardless to consider other factors affecting conditions.Contrasting the stress-strain curve obtained by the finite element model and the stress-strain curve obtained by mechanical tensile test, the results showed that the bond points arranged in different way has relatively large impact on the tensile behavior of the early stages, especially the initial modulus of the material, the main reason is stresses are concentrated on bond points in the initial stage of the tensile, and the main mechanical action at thme time is the bonded points system, which it is the diamond system or stripe system.Contrasting fracture stress distribution and the fibers orientation distribution. they are very same. At advanced stage of the process of mechanical tension, diamond system or stripe system of bond points has been destroy, the main mechanical action at this time is fibers of nonwoven material. The mechanical properties of the fiber and the extent of the damage of the bond points boundary fiber of the nonwoven materials directly determine the fracture stress of the whole material.