I would like to discuss about the major defects of knitted fabric. The two classes of knitted fabrics are the filling knit and the warp knit. Standard test method for stretch properties of knitted fabrics having low power1 this standard is issued under the. Checkers also check for stitching defects in seams, fabric defects in the garment and any other kind of defects those need to be repaired. Detecting defects in weftknitted fabrics using texturerecognition. Knitted fabrics and types list of knitted fabrics textile. In textile industry faults are frequently occurred and stitch length. There are different types of defects found in knitted fabric, but the defects of knitted fabric is less than woven fabric. Drop stitches are randomly appearing small or big holes of the, same or different size, which appear as defects, in the knitted fabrics.
Lesson 8 knitting and basic k information and library. Digital imaging is an adequate technique to determine the porosity of highporosity fabrics. Knitted fabric faults are very different in nature and appearance and are often superimposed. Realtime detection of knitting fabric defects using shearlet. Pdf study on different types of knitting faults, causes. The experiment demonstrates that nwct can achieve the positive segmentation regarding the common defects, such as broken warp, width barrier, and oil, and has excellent performance on these directional defects and regional defects. We start by demonstrating the difference between woven and knit fabrics and then how knits are structured. Still, some defects can have a variety of underlying causes associated with them. The following knitted fabric defects are found in knitted fabric production. Aug 14, 2012 normally fabric roll containing 40 points per 100 square yard are acceptable. This is my attempt to provide a brief detail in regard to the common fabric defects and inspection methods for checking the. Faulty woven fabrics hampers the total quality of woven garments such as shirt, pant, trouser, jacket etc. For changing the stitch length at same count at three same diametric double jersey knitting machine on same rib structure we found the effect of stitch length on common knit fabric faults. The imperfections may be the result of faulty yarn, knitting machine.
Friends and family members apart from being sources of defects also viewed my work from time to time. List of fabric defects woven, knitted, terry and velvet. This is to certify the thesis entitled identifying defect causes of weft knit. The computer techniques are used in the processing of the defects images of weft knitted fabrics in this paper. Knitting technology definition and types of knitted. In a flat piece, the yarn is raveled back and forth. If fabric tension too tight then loops length is low.
Knitted fabric faults can also be detected by inspecting yarn input tension and loop but only few types of faults are concerned by these methods. Thus, the sensor could run independently on the pc. Dec 11, 2015 for that reason knitted fabric manufacturer always try to produce their fabric defects free, but several defects may occur in the products process. Human inspection by using knitted fabric inspection machines remains today the most used way to classify faults after knitting and after finishing 5.
Pdf in this study we have done study on knit fabric faults and their causes. Kt session 29 knitted fabric defects copy righted material. Knitted fabrics description of defects vocabulary etoffes a mailles description des defauts vocabulaire 1 scope this international standard describes defects which commonly appear during the inspection of knitted fabrics. The fabric is reversible and identical on both sides of the fabric. These machineries are designed so that rolls of fabric can be mounted behind the inspection table under adequate light and rerolled as they leave the table. A defective portion in the fabric marked by distortion or cutting of warp and weft. A defect is a fault that would reduce the expected performance of the knitted fabric or, if it appeared in.
Application of knitted fabrics in technical and medical textiles karoly lazar hungarian society of textile technology and science abstract. Knitted terry is pile jersey fabric made with a special attachment in regular circular knitting machines similar to woven fabrics. Pdf study on different types of knitting faults, causes and. All stitching defects are sent to a repair tailors. Loop forming is the basic operation to produce knitted fabric. Knitting defects free download as powerpoint presentation. To name a few breakage of needle during knitting, faulty yarn, lack of machine maintenance or even improper storage conditions can lead to holes.
Astm d 5430 as per astm d 3990, standard terminology relating to fabric defects defects are named and identified for woven fabrics. Almost all the defects appearing in the vertical direction in the knitted fabrics are as a cause of bad knitting elements. Imperfections are the occurrence of knots, slubs, thick or thin yarns, and neps in the fabric 4. Inspection machineries are either power driver or the inspector pulls the fabric over the inspection table. The warp yarns of 44 dtex12 nylon 66 are wound at tensions of 4, 6, 8, 12, 16 and 20 cn. A catalogue of visual textile defects fibre science. If the yarn count is not correct on regarding structure, gauge, course and.
I will be covering the following three aspects in this article. In readymade garments sector, knit or knitted fabrics is used for manufacturing the knitted garments such as polo shirt, tshirt, sweat shirt, sportswear, swim wear, sweater, under garments, childrens wear etc. Standard test method for stretch properties of knitted. The fabric has alternate courses of knit stitch and purl stitch. Normally fabric roll containing 40 points per 100 square yard are acceptable. There are various types of defects which occur in the knitted fabrics of all. During loop formation the yarn breaks in the rejoin of the needle hook. The fabric is made of two sets of yarns, in which one set of yarn makes the pile, while the other set of yarn makes the base fabric. Warpknitted fabric defect segmentation based on non. Online fabric defect inspection using smart visual sensors. Hemashield knitted double velour fabric and the hemashield platinum finesse ultrathin, knitted cardiovascular patch indicates the direction of greatest tensile strength. A defect of the knitted fabric is an abnormality which spoils the aesthetics i. So, at this stage checkers segregate the defective garments and defective garments are sent to the repair section.
Standard specification for tolerances for knitted fabrics. There are various types of defects which occur in the knitted fabrics out of which majorly found defects like hole, knit. Fabric inspection four point system textile study center. Oct 25, 2016 if fabric tension too tight then loops length is low. The processing of the defects images of knitted fabrics. A number of different methods have been proposed to determine the porosity of knitted fabrics, which include digital imaging, geometrical modeling, and air permeability. In textile industry faults are frequently occurred and stitch length has a direct effect on these faults. Apr 02, 2018 common defects of fabrics during manufacturing process includes back fabric seam impression, birds eye, bowing, broken colour pattern, colour out, colour smears, crease mark, drop stitching, dye streak in printing, hole, jerk in, knots, mixed yarn, mottled, needle line, open reed, pin holes, press off etc. Study on different types of knitting faults, causes and. As a textile engineer you should know about the major woven fabric faults which produced during woven fabric manufacturing. It is acknowledged that nwct will provide a new way to detect warpknitted fabric defects automatically. This is my attempt to provide a brief detail in regard to the common fabric defects and inspection methods for checking the fabrics.
List of fabrics used in knit garments manufacturing. Identifying defect causes of weft greige knitted fabric. Therefore tension of fabric always should be checked to obtain high quality of knitted garment. Fabric defects and fabric defects inspection methods. In a previous work 6, neural network methods were applied to images of simple circular knitted fabrics for classifying faults. Many readers, asking me to provide information in regard to the fabric defects and the common visual inspection methods for the fabrics. If fabric tension too loose then loop length is high. In detecting and classifying defects, image analysis has been used extensively, especially for woven fabric defects 717. This lesson is the first in our 7part series on working with knit fabrics. The result showed the successfulness of the methods, but this approach is not useful in industry because the process. To record or to collects defects during inspection a simple check sheet must b used.
First, the fabric defects images are collected, and are pretreated in order to be seen more clearly. A fabric roll 120 yards long and 46 inch wide contains following defects. Minimization of defects in knitted fabric svkms nmims. Fabric defect, causes and remedies toh problem kya hai. Barre is typically found parallel to the filling of woven fabric or to the courses of circular knit fabric. Barre is noticed in a fabric when the visual perception of colour of a particular portion of a fabric is different from that of an adjacent portion. If the yarn count is not correct on regarding structure, gauge, course and density. You will learn the meaning of terms like knit and purl, wale and course and how a weft knit differs from a warp knit. They can be raveled readily, and they easily develop runs, or ladders, when a yarn is broken. It is very natural that in the course of knitting fabrics, imperfections occur. Fabric is inspected to identify the severity and type number size location of defect. By doing this study fabric defects like hole, lycra break and knit fly reduced by 26%, 36% and 41% respectively.
It is acknowledged that nwct will provide a new way to detect warp knitted fabric defects automatically. A number in parentheses indicates the year of last. Knitted fabrics are produced by two general methods warp knitting, and weft knitting, and each method produces a variety of types of knitted fabrics. Knit fabric defects free download as powerpoint presentation. There are various types of defects which occur in the knitted fabrics of all types caused by a variety of reasons. Pdf minimization of defects in knitted fabric researchgate. Defects in garments, sewing defects, colour effects, sizing. Defects in knitted fabrics, skew, bias, bowing, twisting, knots, thick yarn, thin yarn, uneven yarn structure, course yarn, slub, needle line, needle run, fabric run.
We will teach you about how knits are made and about the different types of yarns, so that when. A grade is a numerical value given to fabric based on number, size and severity of defect seen during visual examination. Purl knit is made by knitting yarn as alternate knit and purl stitch in one wale of the fabric. Detection and classification of defects in knitted fabric structures. Vokabular knitted fabrics description of defects vocabulary. There are various types of defects which occur in the knitted fabrics out of. Experiment 03 fabric bands knitted using different tensions in order to investigate the loop length variations caused by the tension of warp yarns, a warp knitted fabric with six lengthwise bands of different warp yarn tension was prepared. Holes are the results of yarn breakage or yarn cracks.
A check sheet includes general details, details of fabric lot, fabric defects according their sizes, summary of fabric defects, quantity inspected and total penalty points and result of the fabric lot after inspection. However, these fabrics are not as stretchable as the weft knitted fabrics. Knitted fabric defects and remedies fashion2apparel. Major defects of knitted fabric textile merchandising. Jul, 2017 checkers also check for stitching defects in seams, fabric defects in the garment and any other kind of defects those need to be repaired.
Common defects of fabrics during manufacturing process includes back fabric seam impression, birds eye, bowing, broken colour pattern, colour out, colour smears, crease mark, drop stitching, dye streak in printing, hole, jerk in, knots, mixed yarn, mottled, needle line, open reed, pin. A wide variety of file fabric options are available to you, such as bag, home textile, and garment. In a warp knitted structure, each loop in the horizontal direction is made from different thread and the number of thread used to produce such a fabric is at least equal to the numbers of loops in horizontal row. In the modern textile industry, visual surface inspection of fabrics plays an important role in quality control of textile and fashion products because defects on the fabric can have a great impact on costs and grading of final products. Common fabric defects and its causes textile school. The proposed fabric defect inspection system based on smart visual sensor was then installed on the warp knitting machines and operated successfully. Some of the common fabrics used in garment industry as below 4 4. A defect is a fault that would reduce the expected performance of the knitted fabric or, if it appeared in a prominent position in an article made from the fabric, would readily be seen and rejected by a prospective purchaser. This paper has investigated the porosity of knitted fabrics using digital imaging techniques. Microscopy can also reveal a shift in loop formation in knitted fabrics when twist direction s and z differences are present. Horizontal stripes or streaks of uniform or uneven width, visible in the fabric 3.
The production of terry fabrics is a complex process and is only possible on specially equipped weaving machines. Determination of knitted fabric porosity using digital. Our proposed system achieves the highest accuracy of 94. Tension of fabric directly affect for appearance of garment.
Faultsdefects in the knitted fabrics textile learner. Weavers tapping the fabric with the shuttle tip or pirn on the front rest when inserting a new pirn. In textile industry, woven fabric is produced by interlacing warp and weft yarn. To record or to collects defects during inspection simple check sheet is used. Introduction to knit fabrics university of fashion. View kt session 29 knitted fabric defects from cs 102 at national institute of fashion technology, bangalore. For that reason knitted fabric manufacturer always try to produce their fabric defects free, but several defects may occur in the products process.
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