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The purpose of this paper is to model tension seam pucker by finite‐element method.

A linear three dimensional finite‐element analysis in ABAQUS 6.8 is used to model pucker formation under sewing thread tension. Fabric is modeled as a continuous shell under a constant stitch length and sewing thread tensions is the applied force. Simulation's results are compared with the experimental pucker profiles, which are derived by a triangulate laser, in the term of a surface roughness index.

A consistent correlation between simulation and experimental results is observed which reveals the ability of the model to predict the seam pucker formation of fabrics.

This study modeled tension seam pucker based on fabric's mechanical properties and exerted forces by finite‐element method. According to this study, it is possible to predict fabric deformation after tension pucker occurrence.

The paper aims to establish and introduce seam pucker assessment indicators and their dependence upon the fabric characteristics and parameters of a sewing machine.

Seams pucker defect is specific to garment from lightweight fabrics, therefore the investigation was performed with this kind of fabrics. The structure and friction properties of fabrics were determined. The influence of rotational frequency of the main shaft (varied from 200 till 2,300 min⁻¹) and pressing force (from 25 till 85 N) on seam pucker was analysed. The seam pucker was evaluated by characteristic of sharpness calculated as ratio of pucker height and length.

Analysis of the obtained results allows stating that pucker sharpness increases with growing rotational frequency of the main shaft and decreases, increasing pressing force. On the basis of correlation analysis, the relationship between proposed new indicator of seam pucker evaluation and parameters of sewing machine was sought. The obtained result demonstrates that in most cases the relative pucker coefficient is dependent upon rotational frequency of the main shaft: increasing rotational frequency also leads to higher pucker coefficient. The linear relationship between the pucker coefficient and pressing force was not observed.

This investigation has practical implications in the clothing and other nearly related industries. In the paper, results involved with evaluation of seam pucker are presented.

The research showed that in order to define seam pucker more comprehensive, it is necessary to evaluate not only ratio of pucker height and length, but also the quantity of puckers as well as their propagation. Considering to this, the new criterion for seam pucker evaluation was proposed.

The aim of the present study is to consider the influence of the tensile behavior of fabric and sewing thread on the seam appearance.

In this study, the formation of seam puckering on two elastic and normal woven fabrics was explored. In order to prepare samples, various sewing threads were applied. Test specimens were sewn under five different thread tension levels. Then the appearance of samples was evaluated subjectively to determine their seam puckering grade before and after the laundering process.

The obtained outcomes of this study present that although sewing thread tension increment decreases the seam pucker ranking in the similar sewing condition, elastic fabrics have a greater seam pucker grade compared to the normal fabric due to the fabric extension and contraction during sewing and after sewing process, respectively. In addition, the elastic strain of the sewing thread is the key factor that determined sewing thread's tendency to make seam puckering. Moreover, the laundry process due to the relaxation of the sewing thread decreases the seam pucker grade.

The consistency of the tensile property of fabric and sewing thread is a crucial parameter in improving the seam appearance and obtaining a smooth seam.

Seam pucker is one of the most important aspects of garment quality in the sewing process. Recently, automatic sewing systems have been developed and seam pucker or other defects would have to be automatically inspected in these systems. Two systems of automatic, contactless measurement of seam pucker have been developed. One of the measurement systems, with which surface shape of seam pucker was measured, is based on laser technology. Intensity of reflected ultrasonic wave is measured using another measurement system. The laser measurement system has been applied to moderate or severe seam pucker and the ultrasonic wave system has been applied to the accurate evaluation of very small seam pucker. The result of the evaluation by machine has to match the result of subjective evaluation by humans. To verify this, samples of seam pucker were evaluated using five judges. With the measurement data of surface shape of these samples, the power spectra of the wave form of seam pucker are calculated. Analyses and correlates the relationship between objective measurement and subjective evaluation by discriminant analysis, with the result of subjective evaluation and the power spectra of the samples. Having obtained these relationships, the degree of seam pucker can be measured objectively by both systems.

The paper aims to evaluate the influence of mechanical properties of sewing threads on the seam pucker.

The mechanical properties of sewing thread were obtained performing tensile testing research. The seam pucker of lightweight fabric was evaluated after sewing, then after 24 h, after 48 h as well as after washing and drying. To determine dimension changes of fabric, the relaxation shrinkage was calculated. The results of thread properties and seam pucker were compared.

In respect of seam pucker the best results were established sewing with polyester threads, the reversible strain of which were the least. After washing and drying, the highest pucker was typical of the specimens sewn with cotton sewing threads. It was noticed that increasing the amount of layers in sewing the influence of threads on seam pucker decreases. Washing and drying made considerably greater influence on the occurrence of pucker then time.

This study has practical implications in the clothing and other nearly related industries. In the paper recommendations involved with application of sewing thread and evaluation of seam pucker are presented.

In most cases the changes of sewn thread mechanical properties after sewing is analysed. This study is aimed to determine the influence of thread properties on seam pucker. Recommendations in the area of sewing thread and garment quality are based on the research.

States that computer simulations of seam pucker were executed. The simulations were based on the computer program which predicts the shape of virtual fabric with an assumption that the relationship between stress and strain of the virtual fabric is linear. The simulations predicted the shape of fabric with the conditions such as material puckering and mechanical properties of fabric. The rating of simulated seam pucker changes according to material puckering. It was shown that bending stiffness and tensile modulus affect the rating of seam pucker. Seam pucker samples were made from fabric for comparison. Computerised seam pucker samples were executed utilising the same properties and shape of seam line as the sample fabric. A fairly similar shape was obtained by the simulation.

In our previous study, seam pucker simulation baased on mechancial calculation was proposed. Here, the simulation system is extended to consider collision between fabrics and seam pucker simulation of two strips of fabric is carried out. We adopt non‐linear bending rigidity observed in actual fabric tests and obtained results much closer to the real results. With the consideration of collision and the improved treatment of bending rigidity, the following results were obtained. The wave length of wrinkles is more broadly distributed when material puckering is 0.96 or 0.94 compared to the case of 0.98. The wave length increases as the value of bending rigidity does and decreases as Young’s modulus increases. In the case of two strips seam pucker, the distribution of the wave length is wider than the case of the single strip.

The purpose of this study is to introduce a novel approach for seam pucker analysis based on wave shape parameters.

In this method the uneven wavy curve along the puckered seam line was put into a deconvolution process and broken into several simple Gaussian curves using residual mathematical analysis method. First puckered samples with five different grades were produced and scanned by laser triangulated technology. After implementation of deconvolution method, the key geometrical parameters of the decomposed waves such as number of waves and their shape parameters like wave's area, amplitude and wave length were extracted. In addition, an objective method was developed and five indexes were introduced.

Analysis showed that there is a high linear relation with high correlation between all pucker indexes and subjective pucker evaluation.

The goal of this research was to analyse the five grades of seam puckered samples and extract the basic structural parameters to solidify the characteristic of each puckered grade, in order to exclude the influence of human perception.

The present work has shown that the cause of seam pucker in structurally jammed fabrics is mainly due to the sewing tensions of the sewing threads and that the fabric instead of trying to take up a more jammed configuration, as believed so far, tries to resist jamming and in doing so, buckles out of the fabric plane. The proposed mechanism of seam pucker is based on quantitative and qualitative studies of fabric and thread properties in relation to sewing. The stitch can be regarded as an Euler column consisting of three springs representing a lockstitch seam; a compressed spring in the middle representing the fabric, and two stretched springs either side of it representing the needle and bobbin threads. If the bending and compressional loads are high compared to the bending and compressive stiffness of the fabric, buckling will occur. If the column is stiff by comparison with these loads, then the critical load for the column will not be exceeded and buckling will not occur.

Seam pucker can only be assessed subjectively, by using photographic standards, since instrumental techniques have so far failed to produce accurate results. A low cost means of predicting the degree of pucker has been provided, by correlating measured values of fabric and thread mechanical properties and geometrical relationships with the degree of pucker obtained in the seams. These properties were experimentally measured, for a set of commercial lightweight woven fabrics, and when their values were suitably plotted, three distinct clusters were obtained which, when compared with fabric grading, were found to correspond to severe, critical and acceptable seam pucker. The most important properties were found to be fabric and thread bending, fabric shear, fabric thickness and weight, and certain fabric geometrical parameters using Peirce geometry. The various methods of plotting these properties provide, within the test set of fabrics, a means of predicting the tendency of a fabric to exhibit structural jamming seam pucker.