Objective Evaluation of Seam Pucker

We have developed a process for optimizing sewing conditions to minimize seam pucker using the Taguchi method. The process is applied to two different T/C fabrics with the specified experimental design using an optimum orthogonal array table. The parameters selected for optimization are sewing speed, stitch length, sewing thread tension, and presser foot pressure. The Taguchi process has the following steps: calculate the SN ratios of repeated experimental observations, find the corresponding conditions that influence sewing for a given fabric, determine the optimum values of the sewing conditions, calculate the prediction interval of minimum seam pucker grade with optimum sewing conditions, certify the Taguchi processes that apply, and finally compare the expectation losses before and after improving seam pucker grades. With the Taguchi processes, we can easily determine the optimum sewing conditions for minimizing seam pucker with simple experiments.

Section: Introductionmentioning

confidence: 99%

A Process for Optimizing Sewing Conditions to Minimize Seam Pucker Using the Taguchi Method

Park

2005

“…The CCD cameras were not entirely appropriate due to difficulties with patterned fabrics, and were replaced by laser scanners [9]. In the last few years, a number of other researchers [4,5,6] also did similar work in this field using laser scanners.…”

mentioning

confidence: 99%

Objective Evaluation of Pucker in Three-Dimensional Garment Seams

Fan

Dai

MacAlpine

et al. 1999

This paper considers the objective evaluation of seam puckering on three-dimensional garments. In order to simulate garment surfaces in three dimensions, seamed samples are supported on five different surfaces: plane (both with and without tilt) and curved (both convex and concave). A set of five samples having seams with varying degrees of pucker are prepared from each of five fabrics, and profiles parallel to the seams are measured using a laser distance scanner. These profiles are then filtered using a band-pass Chebyshev filter (where the "frequencies" are measured in cycles/m) to remove the highfrequency component contributed by the individual threads or fabric texture and the low-frequency component contributed by the shape of the sample. These band-pass filtered profiles are analyzed by calculating four statistical parameters and comparing these with the subjective AATCC grades. Excellent correlation is obtained for two of the parameters with the subjective pucker grades. Seam pucker is regarded as a matter of primary concern in garment manufacture. When the sewing parameters are not appropriate to the material selected, puckering occurs along the garment seams, and the aesthetic appeal of the garment deteriorates. The standard AATCC grading method [ I ] is well established but subjective, and therefore subject to error and variability between occasions and locations, particularly for patterned materials and darker shades. It is also time-consuming and involves several people.From the 50s to the 70s, several instruments [2, 3,8] using photo or displacement sensors were developed to measure the surface contours of seams. However, these instruments were not widely accepted due to problems with accuracy and reproducibility. With the development and wide application of computer and sensor technology, a number of new attempts were made in recent years. In 1992, Stylios and his co-workers [10, 11 used a CCD camera to capture the image of a seam,,and this information was then fed to a computer that could predict the grade or severity of seam pucker using an artificial intelligence algorithm. The CCD cameras were not entirely appropriate due to difficulties with patterned fabrics, and were replaced by laser scanners [9]. In the last few years, a number of other researchers [4, 5, 6] also did similar work in this field using laser scanners.Although considerable effort has been put into the objective evaluation of seam pucker, all the work to date has been on samples laid on a plane surface, which is not directly applicable to garments where few seams are completely flat. In this paper, we describe a method for extracting the pucker signal from seam profiles measured with a laser scanner, when the seamed samples are laid on both curved and tilted surfaces to simulate seams in three-dimensional garment surfaces. Four statistical parameters are derived from the pucker profiles and compared with the grades obtained by the AATCC method. Excellent agreement is demonstrated by a linear correlation with two of the paramete...

“…Of the three, tension puckering, caused by excessive thread tension, is the main cause of the seam puckering [2]. However, pucker is rarely encountered, as fabrics are relatively extensible and elastic and are able to absorb a considerable amount of excess energy without puckering.Historically, studies of seam puckering have been focused on the evaluation of seam puckering [3][4][5][6][7]. Park and Kang [1, 2, 8] present a geometric model with five shape parameters to quantitatively evaluate the seam pucker.…”

mentioning

confidence: 99%

Modelling Multi-layer Seam Puckering

Baciu

et al. 2006

When two pieces of woven fabric are joined by a seam, and if the thread is stretched then a wrinkle will ultimately occur at or near the seam line. In addition to thread shrinkage, there are other factors responsible for seam puckering, including presser foot pressure, sewing speed, needle size, stitch density, properties of sewing thread, mechanical properties of the fabric, as well as seam and stitch type [1].In general, the reasons for seam puckering can be classified into three types: (1) structural jamming; (2) tension puckering; and (3) machine puckering. The structural jamming that results when the needle carrying the sewing thread pierces the fabric causes the displacement of yarn and seam distortion. This often happens when high-density fabrics are sewn with a thick thread and needle. Machine puckering is due to the uneven ply feeding. If one or more of the above three conditions exists, seam puckering will be the result. Of the three, tension puckering, caused by excessive thread tension, is the main cause of the seam puckering [2]. However, pucker is rarely encountered, as fabrics are relatively extensible and elastic and are able to absorb a considerable amount of excess energy without puckering.Historically, studies of seam puckering have been focused on the evaluation of seam puckering [3][4][5][6][7]. Park and Kang [1, 2, 8] present a geometric model with five shape parameters to quantitatively evaluate the seam pucker. Although this method can generate a randomly distributed wave mesh to represent the seam pucker, even if implemented by using a neural fuzzy algorithm, it would be insufficient to characterize the seam properly. Inui [9, 10] used an elastic mechanical calculation to simulate the seam puckering of two strips of fabric sewn together. The bending force exerted on the vertex was derived as the gradient of potential energy. However, previous related work is limited to a flat seam without considering the seam type factor. Our main contribution is that we provide a seam model to simulate multi-layer seam puckering. 1 The purpose of this study was to simulate the multilayer seam deformation caused by sewing thread shrinkage. Based on the mass-spring cloth model, our microlevel seam structure analysis on different seam types has allowed us to identify certain parameters that can be used to model various type of seam deformation. These parameters include seam dimension (seam width, stitch length and seam thickness), fabric mechanical properties (stretching, bending and shearing) and friction between different layers of fabric. Definitions of the parameter used in the model are given in the Appendix. Model DevelopmentA seam is considered to be layers of fabric connected with sewing threads. Thus, a seam model would consist of two Abstract This paper presents a method for modelling the seam puckering of multi-layer fabrics by considering the thread shrinkage as well as seam structure and fabric compression properties. A theoretical investigation and numerical calculation of forces acting on the...