Örme kumaş konfeksiyon işletmelerinde karşılaşılan kalite problemleri ve çözüm önerileri

Abstract

Son yıllarda, tüketici eğilimlerindeki değişmeler, nedeni ile örme kumaşlardan yapılan giysilerin kullanımı çok hızlı artış göstermiştir. İnsanların günlük hayatın getirdiği yorgunluğu ve gerilimi üzerlerinden atmak için rahat ve kullanımı kolay giysileri tercih etmeleri örme kumaşlara talebi arttırmıştır. Ülkemizde önceleri iç çamaşırı, t-shirt, gecelik ve pijama gibi ürünlerde kullanılan örme kumaşlar son yıllarda ihracatın da baskısı ile başka giysi türlerinde de kullanılmaya başlanmıştır. Örgü kumaşlar, örgü yapsını oluşturan ilmeklerin özel şekil bağlantıları nedeni ile esnek kumaşlardır. Bu esnek yapı örme kumaş konfeksiyonunda bir takım hatalara yol açmaktadır. Konfeksiyon sektörünün emek yojun bir endüstri kolu olması ve üretimin de çok sayıda birbirini izleyen işlemler sonucu gerçekleşmesi bu hataların daha da artmasına neden olmaktadır. Örme kumaş konfeksiyonunda en sık rastlanılan hataların tespit edilip, neden ve çözüm önerileri ile ortaya koymaya çalışılan bu projede önce genel olarak kalite ve kalite kontrol kavramları üzerinde durulmuştur. Çünkü konfeksiyon hatalarının minimum düzeyde tutulabilmesi ancak işletmelerde belli bir kalite bilincinin yerleşmiş olması ve üretimin her kademesinde kalite kontrolün yapılması ile mümkün olabilmektedir. Örme kumaşların ve örme kumaş konfeksiyon aşamalarından bahsedildikten sonra projenin son bölümünde örme kumaş konfeksiyon problemler ile ilgili incelemeler ve bu incelemelerin sonuç ve öneriler kısımları üzerinde durulmuştur.

Quality, which indicates the performance of a production activity in reaching the aim, has always been a very important subject in industry. Quality Control has been taken only as the correction of defective products and hasn't been taken into consideration tül the last 10 years. However in today's industry, it is accepted as the base of ali kinds of production. At the same time, the limits of "Quality Control" term have enlarged in recent years. This term includes not only raw material ör products, but also working conditions and many other factors. To avoid quality, problems, same majör points should be especially paid attention to. First of ali, quality problems shouldn't be ignored, but should be examined. Quality inspection system should be planned as a method of preventing the formation of mistakes rather than finding and correcting them. Developing the quality shouldn't be thought as a short-term problem, but as a strategic problem for a long-term. The products should be inspected in a very detailed way while controlling the quality as the customer of those products does. Ali the companies should also determine their own quality strategy besides the international quality standarts and specifications. Quality should be described for ali the products and ali production steps. Quality cost should be checked and changes in quality should be under control. it is not possible to reach the quality targets unless ali the people including the general manager and the administrators give the same importance as demanded from workers. Because quality control system needs the team game. Furthermore both hands and brains of these team players should be used to be successful in this game. Like ali the other industrial sectors, quality control plays a very important role in textile industry. This role has been enhanced as a result of the competition in textile sector. Textile manufacturers have to give much more importance to quality to be able to survive amongst the other manufacturing companies which produce similar goods. There are many factors which effect the quality of the products in ready-wear clothing industry. Since this industry has been based on the working effort of employees and the assembly line system in which öne production step has to be followed by the other öne, ready-wear sector is very prone to problems. These xi problems may only be overcome by applying quality control systems properly during the production.Of course it is not very easy to realise this application. A company should believe that the increase in quality is as important as the increase in quantity. In recent years, the usage of garments made of knitted fabrics has been highly increased. There has been a great demand on the usage of knitted garments as a result of the change in consumers'trends. People prefer to wear comfortable and easy- careapparels for reflecting the daily life's stress and exhaustions. As known, the knitted garment relatively to the woven garments fit better and give more practicability to move freely. In the same way, the lightness of the structure increases the comfort. Knitted fabrics fairly differ from the other types of fabrics because of its yarn properties, the machinery used in the production. The fabric specifications are different as well. Knitted fabrics are more flexible elastic due to its changeable form stability, softer and bulky when compared to woven fabrics. Today in the world and also in our country, it has been possible to produce a great variety of knitted fabrics in different designs, fineness, softness and weight. Knitted garments can be used in all seasons. They aren't peculiar to only one particular season. This is an advantage. The changes in fashion industry force the manufacturers to produce interesting, different, appealing clothes. The design variety and the ease of the knitted fabric production enable them to cope with fashion and customers' demands. That's why the knitted fabric usage has been very popular gradually. Despite many advantages of knitted fabrics in the manufacturing mentioned above briefly, they cause many problems as well. Reducing the thickness of the material brings up important problems to the garment manufacturer. To maintain form stability of knitted fabrics and defect of loops at the surface are the major problems. Manufacturerers have the difficulties not only in sewing stage, but also in other stages like fabric control, modelling, pattern preparation and cutting. Quality control starts with raw knitted fabric control until the goods become ready for the shipment in textile companies. Any problem in the fabric (raw or dyed) directly effects the quality in all next production steps. The most important parameters to be checked on knitted fabrics are fabric quantity, width, weight per m2 and fabric faults, all the fabrics delivered from commission firms (knitting firms or dye-houses) should be controlled one by one in special fabric inspection devices. All kinds of defects, fabric faults, etc., should be informed the commission manufacturers as soon as the problem has been obtained to avoid any conflict in the future. Planning Department should find the ideal width which will prevent the fabric from the extreme shrinkage weight and shrinkage tolerations should never be exceeded to get the preferred results. Sewing is a complex binding process achieved by the cooperation of special needles. The most important point in sewing is to choose the proper seam type by taking the fabric structure into account. Seam quality depends on many factors like fabric, loop specifications, sewing machine type and equipments. XH Choosing the suitable ewingyarn is even very important to get a high sewing quality. As a result of the progress in technology, the speed of the sewing machines reached at the extreme limits as 8000 rotation per minute. That is why, sewing yarn qualifications have been increased by the new technologies. It is essential to be able to use the sewing yam which issuitable for the fabric and sewing type. Otherwise it can't be possible to overcome the problem in sewing process. Because of the flexible and unstable form of knitted fabrics (especially circular knitted fabrics), and curling up o the knitted fabric from edges, manufacturers confront with som eproblems during the sewing process. In modelling and cutting phases, while determining the measurement tolerations which have to be given in sewing, these kind of problems must strictly be taken into consideration. Otherwise it may be difficult to obtain the demanded garment measurements and quality. The more the workers using sewing machines are more experienced, the easier these problems can be overcome gradually. The other important point is to be careful with the needle chosen for sewing. The needle end had better be sharp and thin, but the usage of cutting ended needles especially in thin fabrics like single jersey must be avoided in order to prevent needle damages on fabrics. Defect of the loops at the surface of fabrics is another problem to be solved in sewing process. The importance of this problem is reinforced by the fact that it can be noticed during ironing or first washing rather than the moment which this problem takes place. There are main reasons which cause this defect problem. a) Heat reasons b) Mechanical reasons The needle heats at over 200 C as a result of the friction with the fabric surface which it passes through and the sewing yarn which it is in contact with. The heat which occurs on the needle, causes the defect of loops an fabric surface. Mechanical reasons of loop defection are mainly caused by the speed of sewing machines, the needle number (thickness), used in the process, the form of the needle. Under normal circumstances, the needle slides through the loops after penetrating the fabric without cutting or destroying the loops and goes back in the some way. But if the needle is thicker and the speed is higher, the needle' si sliding movement can't be succeeded so easily and since the needle damages the loops, defection takes place. It isn't of course fair to take the subject only on one side. Loops may also be worn out as a result of loop denstiy, humidity on the fabric and the operation applied to the fabric during finishing processes. To minimise the sewing problems of the knitted fabrics, it is necessary to take soma precautions. First of all, all the surfaces that the fabric will contact with, should be even, smooth and clean. xm problems may only be overcome by applying quality control systems properly during the production.Of course it is not very easy to realise this application. A company should believe that the increase in quality is as important as the increase in quantity. In recent years, the usage of garments made of knitted fabrics has been highly increased. There has been a great demand on the usage of knitted garments as a result of the change in consumers'trends. People prefer to wear comfortable and easy- careapparels for reflecting the daily life's stress and exhaustions. As known, the knitted garment relatively to the woven garments fit better and give more practicability to move freely.In the same way, the lightness of the structure increases the comfort. Knitted fabrics fairly differ from the other types of fabrics because of its yarn properties, the machinery used in the production. The fabric specifications are different as well. Knitted fabrics are more flexible elastic due to its changeable form stability, softer and bulky when compared to woven fabrics. Today in the world and also in our country, it has been possible to produce a great variety of knitted fabrics in different designs, fineness, softness and weight. Knitted garments can be used in all seasons. They aren't peculiar to only one particular season. This is an advantage. The changes in fashion industry force the manufacturers to produce interesting, different, appealing clothes. The design variety and the ease of the knitted fabric production enable them to cope with fashion and customers' demands. That's why the knitted fabric usage has been very popular gradually. Despite many advantages of knitted fabrics in the manufacturing mentioned above briefly, they cause many problems as well. Reducing the thickness of the material brings up important problems to the garment manufacturer. To maintain form stability of knitted fabrics and defect of loops at the surface are the major problems. Manufacturerers have the difficulties not only in sewing stage, but also in other stages like fabric control, modelling, pattern preparation and cutting. Quality control starts with raw knitted fabric control until the goods become ready for the shipment in textile companies. Any problem in the fabric (raw or dyed) directly effects the quality in all next production steps. The most important parameters to be checked on knitted fabrics are fabric quantity, width, weight per m2 and fabric faults, all the fabrics delivered from commission firms (knitting firms or dye-houses) should be controlled one by one in special fabric inspection devices. All kinds of defects, fabric faults, etc., should be informed the commission manufacturers as soon as the problem has been obtained to avoid any conflict in the future. Planning Department should find the ideal width which will prevent the fabric from the extreme shrinkage weight and shrinkage tolerations should never be exceeded to get the preferred results. Sewing is a complex binding process achieved by the cooperation of special needles. The most important point in sewing is to choose the proper seam type by taking the fabric structure into account. Seam quality depends on many factors like fabric, loop specifications, sewing machine type and equipments. xn The confectionary of the styles with a lot of stitches, should be avoided as far as possible. Chain-seam type should be quite preferred. Singer seam type (flat seam) should be used only in parts where the flexibility is not essential. The number of the stitches per centimetre should be adjusted to five or six for a better seam performance. The stress on the sewing yam should be lowered to the minimum level. If the fabric is rather dry, some softening materials with silicon structure, should be sprayed. cm.) Transport gears of the sewing machines should be as thin as possible (12 per The hole diameter which the needles pass through had better narrow. Combined transport system should be preferred. All the fabric types which will be sewn together should have similar flexibiliy in order to avoid problems. Knitted fabric is usually examined at two stages : after knitting and after finishing. Quality control procedures are also carried out before and during knitting ; before, to set the knitting machine to produce a particular quality and during to check that the quality is being maintained. It is arguable that the knitter's main function is qualiity control, to prevent the knitting machine producing faulty fabric.The rough examination after knitting is to ensure that the fabric is not being produced with visible faults that by feedback can be rectified on a particular knitting machine. Some rough mending may be carried out to prepare the fabric for the dyeing and finishing process. After finishing, the fabric is examined over an examination table,faults are identified and their location marked so that they can be dealt with during spreading or after cutting. Some firms mark only at the selvedge with a coloured tag, others locate the actual fault with a sticker as well. Fault counts can be maintained to assess improving or deteriorating standarts. Visual fault location cannot be 100%,neither can be an operative act other than subjectively and checks on the examiners also need to be carried out. The operatives who build up the fabric lay are also responsible for the quality control of the operation, whether they are spreading by hand or machine.For the knitted fabrics in particular, general and localized stretching or distortion of the fabric must be avoided.Faults must be located and the decisions made about them as regards eliminating them from the lay. Alignment of the features and patterns must be maintained where necessary and end wastage must be avoided.Also of great importance is ensuring that the number of layers in the entire lay. and the sub-numbers of particular colours or patterns are correct. Again procedures must be established to check that this is happening. xiv The accuracy of the marker and its positioning on the lay, or the marking of the pattern pieces on the top layer, must be the subject of close quality control.Dimensional problems can be induced at this stage, as can misalignments of garment portions or misalignments of the pattern within or on the fabric. Another common mistake at this stage is to leave out one or more pieces of the garments. It is also important to identify and label on the marker the relevant sizes of the garment portions, so that after cutting they are assembled in the correct bundles. When cutting by hand with straight knives it is very easy to deform knitted fabric, particularly within the depths of the lay. There is also a strong element of cutter skill.Other faults of bad cutting are the failure to accurately follow lines of the marker, and the cutting off of corners. Auto cutting and die cutting pose less of a problem but it must not be assumed that they are infallible. Constant checking by sampling must be carried out to ensure good standarts. Measures must be taken to ensure that the bundles assembled after cutting contain the correct number of pieces have been identified and compensated for. All the pieces must be for the same size garment. All knitted garment manufacturers operate fnal inspection procedures to ensure that the quality they promise to customers is maintained. Analysis of the records of the final inspections should also provide suggestions for action to improve quality.Examination results in garments being categorized into firsts, seconds and rejects. Firsts pass through to packing. Seconds may be bended or the repaired in some other way, such as strain removal, loose thread tidying,debris removal etc.They move after another examination into first category. Likewise a major rejection fault may be overcome to move the garment into second category. Very few companies allow absolute rejects to occur in their production process, such events are usually associated with an unrecognized problem with the raw material such as excessive pilling,dye fading, dye bleeding,etc.Some faults although, measurable are actually assessed visually. In this project after the introduction part where the quality and quality control systems are described in a very detailed way, you'll find main characteristics and types of the knitted fabrics and also main quality inspection studies in textile clothing companies. This part will be followed by the problems of knitted fabric manufacturing obtained during quality control studies done by myself. The project will be completed with conclusion and proposal parts.