The Influence of Stitch Density and of the Type of Sewing Thread on Seam Strength
Having in mind the complex problems of technological process of sewing, as well as general demands for seams produced in garment production, this research should contribute the development of sewed seams breaking forces. Thus, many measurements of seam breaking forces have been conducted. These measurements enable us to define optimal strength of seam strength that improves the compliance of sewed seams parameters. This paper deals with the influence of the thread type and stitch density on the seam strength. The breaking forces and elongations at break were determined by the standardized method (SRPS 2062) and fabric (tape method) according to SRPS EN ISO 13934-1. Fabric samples used for seam testing were sewed by seam (1.01.01) and stitch type 301 with stitch densities 3, 4 and 5 cm. Optimal seam strength (130.9 Ncm) on the fabric T71, and at the same time the highest strength, has been noticed at the samples with seam line in weft direction with stitch density 5 cm, sewed with polyester thread 20x2 tex count, while on fabric T71 that value is 115.9 Ncm. According to obtained results, it can be concluded that stitch density (3 cm ÷ 5 cm) and the type of sewing thread (cotton and polyester, K1 ÷ K5) have great influence on defining seam sttrength, their inconsistency may lead to great differences in seam behavior.
The effect of using Seams on the quality of sewing techniques of children’s clothing, executed with satin fabrics
This research aims to Detection of the effect of the difference of the Seams types (Plain Seam ‘SSa’, the French seam ‘SSae’ and The Lapped Seam ‘LSr’) on the quality of the implementation of the techniques of sewing children’s clothing for occasions in middle childhood executed with satin fabrics, and Determining the considerations to be taken in to considerate when using this Seams in implementation of the sewing techniques of children’s clothing, research methodology descriptive and experimental were used, (12) models (dress) were implemented. Each of the four sewing techniques (Gathers, Invert, Pleats and Circular) was implemented using the three Seams, A “Product Evaluation Card” was designed to assess the impact of the Seams type on the quality of the sewing techniques of implementing children's clothing from the point of view of specialists, The results showed that there are no statistically significant differences between the effects of the three Seams in the first category related to the effect of the Seam factors on the quality of the sewing techniques, This is due to the stabilization of the Seam factors and variables when the three Seams are executed, The results also indicated that (LSr) achieved a higher rate of impact of Seams on the functional and aesthetic aspects of the quality of the sewing techniques, both in terms of the functional and aesthetic purpose of the sewing techniques or the garment product, This is due to the nature and characteristics of the (LSr), which is suitable for the implementation of all types of design lines, and the high strength, which helps to increase the life span and bear them for frequent use, The nature of the (LSr) makes it possible to use it as an ornament, as well as not to cause wrinkles, the occurrence of eagles or loss of stitches or creams. The garment products, which are carried out using (LSr), are suitable for double-face wear and ensure the comfort, freedom of movement, and ease of care. The differences between the effect of the (SSae) and (SSa), however, did not indicate statistical significance with respect to the functional and aesthetic aspects, where the two seams were similar in characteristics, possibilities and the nature of implementation.
Traceability strategy for gear-pitch-measuring instruments: development and calibration of a multiball artifact
There is a strong demand to ensure the traceability of gear-measuring instruments (GMIs). We propose a multiball artifact (MBA) for the evaluation of pitch-measuring accuracy. The aim of the MBA is to transfer the minimum uncertainty from a calibrated value at the National Metrology Institute of Japan (NMIJ) to a measured value of GMIs at a shop floor. The MBA is composed of equally spaced high-accuracy balls around an axis. The pitch-measuring accuracy of GMIs is evaluated by measuring the angular pitch deviation of the balls instead of the angular pitch deviation of a gear. We calibrated the angular pitch deviation using a coordinate measuring instrument (CMM) at the NMIJ and adapting a multiple-orientation technique. We proposed a calibration strategy of the angular pitch deviation. The calibration value of the pitch deviation for the MBA at the NMIJ was obtained with a measurement uncertainty (U95) of 0.2 µm. We evaluated the pitch-measuring accuracy of a GMI using the calibrated MBA. Each value of U95 for the cumulative and single pitch deviations for the left and right flanks was less than or equal to 0.5 µm. The small uncertainty was transferred from the NMIJ to the GMI.