Purpose An improved waterproof seam production technology (ultrasonic welding-thermo adhesive tape sealing (USW-TATS)) was developed in this study. The technology will improve the waterproof performance of seam which has problem resulted from needle holes and thread like seam leaking and excess shrinkage. Design/methodology/approach Threadless seams were produced by ultrasonic welding (USW) with coated and lamination fabric to replace the traditional sewing process in Sewing-thermo adhesive tape sealing (S-TATS). The process efficiency was evaluated by Methods-Time Measurement (MTM). Seam performance including hydrostatic pressure, shrinkage and tear force was compared among three technologies (USW, USW-TATS and S-TATS). The effect of ultrasonic welding parameters (amplitude, roller pressure and roller speed) on the USW-TATS seam performance was investigated.SEM analysis was carried out to examine the condition and morphology of the joints cross section. Findings It was found that waterproof performance and dimensional stability of USW-TATS seam were superior to that of S-TATS seam. Tear force and hydrostatic pressure increased firstly and then decreased with the increasing of USW parameters in UAW-TATS process. Binary regression relationships were found between the USW parameters and tear force or hydrostatic pressure. Shrinkage decreased with the increasing of roller pressure and speed. Practical implications Research results can be applied to predict seam performance of waterproof clothing, reduce equipment parameters setting time and enhance product quality in industry. Originality/value A threadless production technology (USW-TATS) was proposed to improve waterproof performance and dimensional stability of outdoor clothing seams.

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The incorporation of pressure levels and pressure gradients in the design of compression stockings offers excellent potential to enhance function in the sport science, clinical research and rehabilitation fields. Yet, the connection of processing parameters and structure accompanying the pressure characteristic of current graduated compression stockings (GCS) is not well quantitatively studied. To bridge this knowledge gap, this study aims to analyze the effects of processing parameters, such as elastane yarn count, loop length and elastane feeding tension, on the structure and pressure behavior of GCS in our work. In addition, to investigate the mechanism of the pressure characteristic, two numerical models, the cylinder model and the conical model, are employed to predict the pressure value and the pressure gradient of stockings. The experimental results of the statistical analysis indicate that the loop length is a key factor to control the wale density, length of stockings and final pressure values. Moreover, the elastane feeding tension could affect the course density, girth of stockings and pressure gradient. On the other hand, the numerical results reveal that the conical model is suited for predicting the pressure values because of the change in radius of the limb in the model. The entire experimental and numerical work provide the mechanism for the study basis of processing, structure and pressure characteristics of GCS.

PurposeThe purpose of this paper is to predict the effect of bra pad specifications on breast deformation during jumping using a finite element (FE) method. Breast deformation is a key concern for women during exercise and can be effectively controlled with sports bras. In most studies, the deformation of breasts when wearing a sports bra is measured using motion capture devices to judge their effectiveness. However, the operation of such devices is highly complex and time-consuming. Computer-aided technology is an efficient way to simulate these experiments.Design/methodology/approachIn this study, the breast model was obtained using three-dimensional (3D) scanning. Assembling models were obtained for FE analysis using reverse engineering and computer-aided design (CAD) software. The breast deformation results were obtained by completing pre-processing, solving and post-processing in the FE simulation software. To extend the application of these models, pads of different sizes and thicknesses within the bra were constructed to simulate the effect of pads on breast deformation.FindingsThe calculated root mean square errors were <1%, which indicated good agreement between the FE and experimental data in all the models. Nipple deformation was always the largest in most models. The smallest deformation occurred at the superior position of breasts in all models. In addition, larger pads were not effective in reducing breast deformation; however, thicker pads were.Originality/valueThe method developed in this study provides an effective way to predict breast deformation in multiple positions and is convenient for designing compression bras.

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