经编贾卡间隔鞋面材料提花层结构对其拉伸性能的影响

Influence of jacquard layer structure of warp knitted jacquard spacer shoe-upper materials on tensile properties

为使经编贾卡间隔鞋面材料兼具透气舒适性与良好力学性能,选取4种不同提花层结构的贾卡间隔鞋面材料进行拉伸断裂实验和不同定载荷下的循环拉伸实验,探究在产品设计时由于厚组织与网眼组织的比例不同及排布方式变化导致的织物不同方向上拉伸变形特性的差异。结果表明:提花层结构中厚组织与网眼组织的比例是影响织物拉伸性能的主要因素,增加厚组织的比例能够提高鞋面材料的断裂强力和循环拉伸性能,全厚组织织物的拉伸性能最好;改变厚组织与网眼组织的排布方式也会影响鞋面材料的拉伸性能,增加延展线的数量和长度,纵向减少连续排列的网眼组织线圈横列数以减小网眼尺寸,可改善鞋面材料的断裂强力和循环拉伸性能;织物纵向拉伸性能明显优于横向,在循环拉伸实验中,织物纵向产生的残余变形远小于横向,且循环拉伸后纵向断裂强力高于循环拉伸前的横向断裂强力,故在实际应用中应避免将织物横向排列在受力方向上。

Objective Warp knitted jacquard spacer fabrics are widely used in sports shoes.In order to ensure the comfort of sports shoes,mesh is usually formed in the shoe-upper materials to improve the air permeability,but the mesh inevitably affects the tensile properties of fabrics,and in actual wearing.The shoe-upper materials endure long-term cyclic tensioning and eventually produce irreversible deformation,but this phenomenon is rarely explored up to date.Therefore,it is necessary to study the factors affecting the cyclic tensile properties of shoe-upper materials and optimize the design of the jacquard structure,aiming to achieve a better balance between the permeability and mechanical properties of the material and improve its service life.Method The study selected warp knitted jacquard spacer fabrics with different jacquard layer structures commonly used in shoe-upper materials as samples,and tensile break experiments were conducted on MTS Exceed Model E43 to determine the tensile limit range.Three sets of constant load schemes were designed based on application scenarios,and 200 cyclic tensile tests were carried out on MARK-10 tensile tester to compare and analyze the influence of jacquard layer structure on the tensile properties of fabrics.Tensile break test was carried out after cyclic stretching to compare the mechanical properties of the samples before they were gone through the cyclic tensile test.Results The tensile break results showed that the breaking strength of the same fabric in the wale direction was greater than that in the course direction,while the breaking elongation at break in the wale direction was smaller than that in the course direction,which was due to the chain stitch limiting the fabric elongation.When other conditions are kept the same,the sample with jacquard layer structure only consisting of solid structures has the highest breaking strength and the lowest elongation at break in both directions.Based on this,for every 25%increase in mesh structure,the breaking strength in the wale direction decreases by 8.60%-11.60%,and the breaking strength in the course direction decreases by 28.54%-31.24%.When two samples have the same composition percentage of solid structure and mesh structure in the jacquard layer,a greater number of continuous courses in the wale direction represents a larger mesh size,which reduces the breaking strength of the fabric.This is because the solid structure has more yarns under tensile and can bear lager external force.Most of the fabric deformation occurred at the initial stage of cyclic tension,and the residual deformation generated in the first cycle is the largest,accounting for 58.38%-66.52%of the total residual deformation.With the increase of the number of cycles,the residual deformation gradually accumulates,and the increment gradually decreases.The cyclic tensile properties of fabrics differed greatly in wale and course directions.Under the same loading conditions,the residual deformation produced by cyclic tensile was much larger in the wale direction than in the course direction,which is because the tensile strength of the fabric in the course direction is much less than that in the wale direction,and the elongation at break in the course direction is larger,so that the deformation produced by stretching in the course direction is much larger too.Under the same loading conditions and basic structure,the sample with a greater percentage of solid structure in the jacquard layer has a less residual deformation,indicating that it has a lower degree of deformation and excellent cyclic tensile resistance.When two samples have the same ratio of solid structure to mesh structure composition of the jacquard layer,the cyclic tensile resistance of the fabric could be improved by changing the arrangement of the mesh structure to increase the number and length of underlaps and reduce the number of continuous courses in the wale direction to reduce the mesh size.After cyclic stretching,the breaking strength of the fabric in both directions is significantly decreased,and the sample with the least percentage of solid structure in the jacquard layer shows most significantly.Conclusion The composition percentage of solid structure and mesh structure in the jacquard layer is the main factor affecting the tensile properties and cyclic tensile resistance of shoe-upper materials.Increasing the percentage of solid structure and changing the arrangement of mesh can affect its tensile property.The fabric with jacquard layer only consisting of solid structure has the best tensile property.The tensile property of the fabric in the wale direction is obviously better than that in the course direction,so in practical application,it should be avoided to make the fabric transverse and the force direction the same.