Seamless Garment Technology

KNITTING TECHNOLOGY DOCUMENTATION ON SEAMLESS GARMENT KNITTING

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CONTENTS SNO TOPIC PAGE NO 1 Knitting of seamless garments 3 2 Three dimensional garment knitting on v-bed machine 3 Diagram of knitting process 8 4 Advantages of seamless garments 9 5 Technical issues 11 6 Seamless knitting machines 12 7 The cad system 13

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KNITTING OF SEAMLESS GARMENTS Seamless knitting technology creates one entire complete garment with minimal or no cutting and sewing process. This technology eliminates post labor work which saves time and production cost. In addition this technology offers comfort and better fit by eliminating seams. Seamless garment knitting creates a complete garment by several different carriers (feeders) with minimal or no cutting and sewing processes. Thus, seamless knitting has the capability for production time and cost-saving by removing post-knit processes such as the linking or sewing and cutting operation.

It also minimizes yarn consumption by reducing the cutting waste and can achieve higher productivity. Machine productivity in knitting is expressed in pattern rows per minute. Complete garment knitting can be achieved either on a circular knitting machine or a flat (V-bed) knitting machine. However, seamless circular knitting machines are different from seamless flat knitting machines in that circular machines such as the Santoni create only a single tubular type of garment. Seamless flat knitting machines such as the Shima can create more than one knitted tube at the same time, and the tubes are joined together on the machine.

Seamless garment can be developed through knitting technology by widening or narrowing the fabric by doing the loop transfer mechanism. Loop transfer is nothing but transfer of stitches from one needle to other needle this mechanism is described with the above figure that is how the loop transfer taking place. For the fully fashioned garment body portion, sleeve portion are prepared separately but the joining of these portion require a sewing process or linking process.

THREE DIMENSIONAL GARMENTS KNITTING ON V-BED MACHINE The complete garments knitted on circular machines may also need minimal cutting as seen in Figure. In addition, the complete garments created by circular knitting machines still require minimal seam joining on one body tube and two sleeve tubes as well as the finished edges. Santoni has recently introduced the SM4 TL2 machine which shapes the knitted tube and will eliminate the cutting process.

On the flat machine, the three tubes are knitted on a pair of front and back needle beds. The flat machine knits and transfers loops between the front needle bed and the back needle bed with different yarn carriers for one body tube (Feeder 2) and two sleeve tubes (Feeders 1 and 3). The three tube knitting continues to the underarm point. At the underarm point, the two carriers knitting sleeve parts (Feeders 1 and 3) are taken out of the knitting zone. The remaining carrier (Feeder 2) that knitted the main body part knits together the three tubes into one tube. The tubes are joined at the underarm points, shoulders and neck points. In this manner, seamless garment knitting is accomplished. However, in order to make loop transference for performing shaping or design structures, loops should be formed by selecting alternate needles.

Alternate stitch notation on complete garment knitting By loop transference using the alternate needles, single jersey tubes as well as rib type tubes can be knitted on the complete garment machine. However, due to the alternate needle selection on seamless machines, the garment tends to be more open and less elastic than a traditional fully fashioned garment. This requires the use of more elastic yarns on the seamless knitting machine compared to the other regular V-bed machines such as fully-fashioned machines.

The figure shows: The three dimensional complete garment knitting until underarm point. The three dimensional complete garment knitting after underarm point. In addition, the number of tubes knitted on the machine depends on the desired type of knitted product. The complete garment machine does not have to create three tubes all the time. For instance, to create a sweater, it requires three tubular typed forms. On the other hand, a seat cover may require only one type of tube for the complete cover, but could also provide an integrated attachment tube.

Loop transference on complete garment knitting Seamless garment knitting can be seen as a more advanced technique in that it can connect the three tubes together to create a sweater and has the capability to increase and decrease the dimensions of the tubes. Moreover, various structures such as plain, rib, purl etc can be created within the seamless garment at the same time.

DIAGRAM OF KNITTING OF THE PROCESS OF KNITTING A SEAMLESS GARMENT

ADVANTAGES OF SEAMLESS GARMENTS New technology has their unique advantages both commercial as well as economical, this seamless technology also not exception .The following advantages we can find from seamless technology. Freedom of body movement: Generally the seam portion of any garment is not having the same elasticity as compared to the body fabric, so the difference in elasticity will affect the free body movement. Since the seamless garment doesn’t have any seam in it structure this problem has been eliminated. Wider range of fit for different range of body shapes: In a single garment measurement can suitable for wider range of fit for different range of body shapes

because of its higher elasticity Inherent softness: There are no bulky and annoying stitches at the underarm points, shoulders and neck lines, which may cause irritation to the wearer, since the garment having seam free structure it provides the soft feel only. It reduces labor cost: Due to the elimination cutting and sewing process it is obvious to reduce more labor involvement. Minimum yarn consumption: Most of the fabric wastages occur at cutting stage, since this seamless garment excludes this process fabric consumption per garment is less, so the yarn consumption also very low. Additionally, yarn consumption can be minimized at knitting by means of effectively analyzing yarn feed through the computerized system on the knitting machine. Smaller work space: Involvement of sewing operation is less except few cases in the garment production system, which leads less space requirement. Reduce yarn and fabric inventory: Cutting and sewing process require more fabric as well as yarn inventory due the absence of this process no need of maintaining huge inventory. Quick samples: Sampling is a costly as well as time consuming process, because small portion of fabric as well accessories need to be prepared .since this seamless garment is exemption, here we can prepare quick samples. Fewer product failure: Most of the garment failures are due to seam failure the seamless garment doesn't have the seam, so that garment failure is also very less. Engineered features like comfort, fit, and ventilation we can obtain from this technology. Cost of production is less: This leads to saving of production costs up to 40 percent compared to the customary garment production system Design possibilities: Seamless garment Technology not only to create several types of tubular formed knitting but also to build diverse design structures on the tubular knitted garments simultaneously. Just in time production: Just-in-time production is possible with the help of seamless technology. In certain markets, seamless knitting could be considered for mass customization by rapid design changes according to customers' requirements through computerized knitting systems. In addition to the above an entire piece produced from seamless technology is claimed to provide more consistent product quality .Consequently, seamless knitwear is promoted to look better, fit better and is believed to be much more comfortable. This technology also allows knit designers to create design structures and patterns across the entire garment, and also it allows for mass customization with respect to customer requirement .In the global environment, according to Shima, seamless garment knitting puts less stress on the environment by minimizing waste disposal APPLICATIONS IN VARIOUS AREAS Apparel: A Variety of seam free products has been created like hand gloves, socks, hats, T shirts and Sweaters. Based on the machine type and gauge the product design will be varied. In addition to that complete garment making machines are available in pilot form to produce trousers and skirts. Automotives Courtaulds and General Motors Corporation had developed the new three dimensional knitting technologies for their seat cover making in the year of 1985. Researches are showing that the automotive seat covers made by seamless knitting is having great market potential and that brings down the warranty cost. Likewise Lear Corporation has patents on three dimensional knitting technologies which will help to design a new seat cover with computer modeling tool that will reduce the design time by 25%. Medical textiles Three dimensional Knitted fabrics have also been used for medical purpose .Some of the tubular knitted structures like bandages, orthopedic support and medical

compression stockings are examples .wearable electronic made from Knitted structures also used for online health monitoring purpose as well as military application. Textronics Inc has developed Textro-monitoring system which is used to monitor human bio physical parameters like respiration and heart rhythm. TECHNICAL ISSUES Although seamless garment knitting technology provides a variety of advantages for the knitting industry, it still has several technical issues. 1) 2) 3) task. 4) 5)

The main problem in complete garment knitting is fabric take up5. Maintaining the tension of each loop (i.e., stitch) is difficult. Fabric design as well as garment design on jacquard is highly difficult Problem to make the welt and cuff portions. Frequent changes in the knitting machine setting

DIFFERENCE BETWEEN CUT AND SEW PRODUCTION AND FULLY FASHIONING GARMENTS Cut and Sew Production Fully Fashioning Garments(seamless)

In cut and sew production system the panels are cut by means of cutting knife and then sewing is carried out Shape of the Garment can be widening and narrowing by means of loop transfer mechanism. Loop transfer is nothing but the move the stitches between the needles. Here additional cost will be incurred for cutting and sewing This eliminates cutting and sewing operation. SEAMLESS KNITTING MACHINES Santoni is now known as the world leader in Seamless Machine Manufacturing. They have produced the seamless warp knitting machine with the model of SDW 8. It is a double needle bar Raschel machine contains 8 guide bars with a working width of 44 inches. This machine can form 2 seamless garments side by side in a chain formation which can be separated later by cutting. Santoni has recently introduced the SM4 TL2 machine which shapes the knitted tube and will eliminate the cutting process. The new Machine produced from KARL MAYER, called "Seamless Smart" is designated as 'DJ' series. The very first machine in this series is DJ 4/2, was developed by Nippon MAYER Ltd. The working width of this Machine is 42", can operate at a rate of 1, 000 stitches/minute. The Shima Seiki company invented the Whole Garment machine and introduced the commercial complete garment knitting (SWG-V machine) in 1995 at ITMA (International Textile Machinery Association). In recent years, several companies have developed seamless or complete garment machines such as Santoni, Sangiacomo, and Orizio Santoni, part of the Lonati Group, is the biggest supplier of the circular knitting machinery. Lonati has recently acquired Sangiacomo and its expanded seamless circular knitting technology is in the forefront of the industry. Santoni, whose customers include Nike, Adidas, Sara Lee etc, offers 14 different models of circular knitting machines, from 7 to 32 gauges. The machines produce swimwear, sportswear, outerwear, underwear.

THE CAD SYSTEM CAD system is a totally-integrated knit production system that allows all phases including planning, design, evaluation and production. Specifically, the loop simulation program permits quick estimation of knit structures without any kind of actual sample making. The program provides an opportunity to see knit problems and to try out diverse knit structures on the computer system before beginning the actual knitting. In the CAD system, each different type of knitting loop is represented by different colored squares. For example, as seen in the following figure, color number 1(red) indicates a jersey (face loop) and color number 2 (green) indicates a reverse jersey (rear loop). Thus, the following red colored figure shows how a single jersey structure can be displayed on fully fashioned CAD system machine.