Abstract: One-sided-stitching techniques can enhance the mechanical properties of composites in the vertical direction, improve the interlaminar damage tolerance, and have the advantages of flexible operating space and applicability to a wide range of structural components. The one-sided stitching device is prone to several phenomena such as missing hook, slackness of the stitching, tightness of the stitching and inaccurate stitching distance during the stitching process, which results in poor stitch quality and low success rate of the stitching. 
On the basis of analyzing the working principle of the one-sided sewing device, the mathematical model of the thread take-up mechanism is improved based on the concept of balancing the supply and demand of the seam quantity, and the parameter analysis is carried out by using the Matlab software to meet the synergy between the supply quantity of the stitching of the thread take-up mechanism and the seam quantity required for sewing. Combined with the designed layout of the thread path, the stable molding conditions of one-sided sewing stitches are improved. The experiment is divided into three groups, namely, no thread take-up mechanism group, additional thread take-up mechanism group and improved experiment group. The position of the nut of the tension adjuster is controlled to change the spring preload force, so as to maintain the same stitch tension in each group before the start of the experiment, and to investigate the influence of the thread path layout on the stitch. The experimental materials are woolen felt, carbon fiber fabric, composite sponge, PVC leather and glass fiber fabric, and the thickness of the materials is about 1.5 mm. Specifically, the carbon fiber fabric and glass fiber fabric are stacked, the thickness is about 1.2‒1.5 mm. In these three parts of the experiment, 10 stitches, 20 stitches, 30 stitches, 40 stitches and 50 stitches are sewn in order, with a total of five groups of stitches, and each stitch is sewn three times and the average value is taken as the experimental results.
The experimental results show that the improved experimental group shows significant improvement in the quality of the thread stitches compared with the no thread take-up mechanism group and the additional thread take-up mechanism group. There are significant differences in stitching success rates under different experimental materials, with PVC leather having the best stitching effect. The improved device significantly improves the seam quality and verifies the rationality of the structural design of the unilateral sewing device.

Key words: one-sided-stitching techniques, thread take-up mechanism, seam quality, thread path layout, balance of supply and demand, one-sided sewing device

摘要： 为解决单面缝合装置在缝合过程中链式线迹质量差、缝合成功率低的问题，在分析单面缝合装置工作原理的基础上，基于线量供需平衡理念，改进了挑线机构的数学模型，并利用Matlab软件进行了参数分析，以满足挑线机构的供线量与缝合需线量协同。结合设计的线道布局，完善了单面缝合线迹稳定成型条件。研究表明：改进实验组在线迹质量上相较于无挑线机构组和增设挑线机构组有明显改善；不同实验材料下的缝合成功率存在显著差异，其中PVC皮革的缝合效果最好。改进后的装置显著提升了线迹质量，验证了单边缝合装置结构设计的合理性。

关键词: 单面缝合技术, 挑线机构, 线迹质量, 线道布局, 供需平衡, 单面缝合装置