Tài liệu The history of jeans

JEANS - THE BLUE PHENOMENON ran a pedlary at that time. So Levi and his brother followed their parents´ footsteps and also became pedlars. When the great gold rush began in 1850, however, he decided to take part and went over to San Francisco in California. He took with him a spade, a pickhammer and a bale of fabric out of brown sail cloth which was meant to put up a tent. This did not happen, however: Levi found out that the gold diggers´ hard work in the mines made their clothes get worn out very quickly and he produced stout working trousers out of the sail cloth he had taken with him which he called „half overalls“. When he continued producing these trousers he used cheap cotton fabrics coming from Genova. At that time Genova was a flourishing place where cotton was exported all over the world. The name of the town of Genova was modified into „jeans“ in the American slang. At the end of the sixties of the 19th century he replaced the brown sail cloth by an indigo-dyed, wearresistant cotton fabric coming from France. The name of this fabric was „Serge de Nimes“. Serge is the French expression for a combined twill and Nimes is the French town where the fabric comes from. The fabric´s name Serge de Nimes was quickly turned into „Denim“ in American colloquial language. By applying this indigo-dyed combined twill the first jeans out of Denim was almost born - or better sewn. The only thing missing were the famous metal rivets. The application of metal rivets for jeans is due to the Polish emigrant Jacob W. Davis, also called Jacob Youphes. Although the working trousers out of Denim were stout they had a tendency to get worn out where The History of Jeans When talking about jeans the name Levi´s is one of the first to be mentioned. Levi´s which stands for Levi Strauss is normally called the forefather of jeans. When tracing back the history of these trousers to its origins it is true that Levi Strauss played an important role concerning their development and distribution but he had also other inventive business partners. Now the question is: who has sewn the first jeans and where does the history of this „blue phenomenen“ begin? Ill. 1: Levi Strauss in the year 1860 In 1847, at the age of 17 Levi Strauss left his Frankonian native country in Germany and emigrated to New York together with his family. The members of the Strauss family were capable and skilful businessmen and 1 the pockets were. Jacob Youphes mended the trousers with a needle and thread. One day a customer inspired him to repair the torn off pockets with the help of rivets. From then on Jacob Youphes made a lot of money out of repairing trousers. Since he was worried that his invention might be stolen he wanted to apply for a patent. For doing so, however, he needed a financially strong partner. For that reason he addressed the manufacturer of the trousers that he mended, Mr. Levi Strauss. Levi Strauss agreed and together they applied for a patent to strengthen the pockets of the trousers and Levi Strauss acquired a share of 50%. This patent was written down in 1873 and can thus be called the true year of birth. Under the management of Levi Strauss the jeans were now produced in series. Since the trousers were so stout not only the gold diggers liked them but – which is not surprising in America the cowboys appreciated them very much, too. When the trousers were applied as working trousers for cowboys, however they got worn out at the crotch tip. This was no problem for Levi Strauss and Co. since they reinforced the trousers again with metal rivets at the crossing point of the four seams at the crotch tip. The metal rivet at the crotch had to be removed quickly since the way of living of the cowboys had not been taken into consideration. The cowboys used to prepare their meals at the campfire and then they spent the rest of the evening sitting around the campfire. When the cowboy approached the fire too much at night, however he quickly learned the difference between the physical conductivity of cotton and metal. Those wearing these trousers were then suddenly startled out of their sleep. By knowing very well the need for such a stout garment and thanks to the good cooperation with Jacob Youphes as well as his very good instinct for marketing Levi Strauss is still an important brand name in today’s textile industry. The jump across the ocean In addition to Coca Cola and Rock´n Roll the Jeans made its way to Europe with the help of the American GIs. The distribution took place by means of so-called „PX-shops“ where only American soldiers were allowed to buy. At that time there was a great demand for the „American trousers“ as they were called, especially by young people. Thus, a trade with jeans developed and the supplies came from remaining stock as well as from auctions of the American army. The first autonomous attempts to produce similar trousers on the European market are due to Albert Sefranek who came from Künzelsau. Sefranek who intended to find new markets for the company of his parents-in-law, Messrs. Luise Hermann „factory for working clothes“ regarded the European version of the jeans a possibility of completing his assortment. The first problem Sefranek met with was to get dress patterns for jeans. So he went to the infamous station quarter in Frankfurt and got acquainted with an American GI in a bar. On the very same evening he initiated the first business transaction with the American soldier. He ordered 6 original American jeans in different sizes which he received the 2 other day and he „paid“ 6 bottles of hard liquor for them. He returned to Künzelsau with the trousers in his luggage, cut them open and thus had the dress patterns for the first 300 trousers. Since the original Denim was hard to get, however, because it was very expensive and importation licences could hardly be obtained indanthrendyed twill cloth was applied for these trousers. Due to its very good fastnesses it was not possible to obtain the desired used-look even after the trousers had been washed several times. In the middle of the 1950´s Sefranek finally succeeded in importing the genuine Denim from America. Together with the distribution of his own trousers Sefranek tried to make a contract with Levi´s which was supposed to secure him the right to sell the original jeans in Europe. By travelling to the USA and by negotiating with Max Katzburg who was then the exporting manager of Levi´s he intented to lay the foundation stone. With the consent given to him by Katzburg he travelled back home and ordered the first 20.000 trousers. Shortly before they had given their final consent, however, Levi´s withdrew their consent and granted the licence to Messrs. Paterson Clothing. For that reason Sefranek concentrated on distributing his own trousers which soon appeared under the name of „Mustang“. Until the end of the sixties the importation of finished articles out of cotton was subject to strict import restrictions. When this legal instruction was no longer valid mainly American companies such as Lee, Lois or Wrangler placed their articles on the European market by opening their own branches. In the 70´s the boom for jeans began. Up to this time they had mainly be considered to be working clothes and young people had used them to demonstrate the „American Way of Life“; now the established readymade clothing factories and fashion shops also used their chance. Very expensive marketing campaigns led people believe in a certain lifestyle when wearing jeans. In the year 1977 the first designers ´ jeans were placed on the market and until the beginning of the 80´s the basic jeans was modified almost beyond recognition. When there was a comeback of the classical, plain form in the middle of the 80´s the jeans became popular for Yuppies who preferred luxurious trademarked articles. So much for the history of jeans. From yarn to grey fabric Production of the yarn The classical jeans is produced out of indigo-dyed Denim fabric. The special character of this fabric – only the warp thread is dyed – makes it necessary to carry out dyeing in yarn form. The yarns applied for Denim were exclusively produced on ring spinning machines in former times. The development of OE yarns - by applying smaller rotors with a spinning speed of up to 200 m/min has led to the application of OE rotor yarns both for warp and weft. The yarns applied for weaving must be of high quality: a high fibre 3 strength, regularity as well as a small part of short-stapled cotton fibres belong to the basic features of the Denim yarn. For regular jeans qualities the warp yarns are spun in a fineness of 50 to 90 tex, for the weft yarn the finenesses are mainly 75 to 120 tex. If Denim is made out of Tencel or Modal especially for jeans shirts the finenesses are up to 25 tex. replaced the woad which was one of the most important dyeing plants up to this time. Only the leaves were used for good qualities whereas the leaves together with the stalks were applied for normal qualities. In a vat filled with water and partially with human fermented urine as alkali donor stems and leaves were exposed to a putrefactive process. During this putrefactive process hydrogen was created by means of micro-organisms which, as a reduction agent, transformed the dyestuff contained in the Indigo plant into a water-soluble form. When this process was over the whole mass was filled into a liquid where the fermented mass was stirred with poles. The reason for doing so was to transform the Indigo into its waterinsoluble form again by air oxidation. In a last step the water-insoluble dyestuff particles could then deposit on the bottom of a stationary vat. Indigo Special attention shall be paid here to Indigo, the „king of dyestuffs“ since it plays an important role in obtaining the jeans effect. Indigo belongs to the category of water-insoluble dyestuffs. It was first mentioned in a book 13 BC; at that time the name Indian blue indicated the country the colour came from. It is said to have been used for dyeing in India and China 2000 years BC already. The Indigo plant is used for preparing Indigo (ill. 2). Then the liquid standing above was drained and what was left was a thin mash which was dried in the open air and was put on the market in pressed or in powder form (ill. 3). Ill. 2: Indigo tinctoria L. Ill. 3: Trading form of Indigo at that time, approx. 9 cm length of edges and 163 g in weight This plant came to Europe in the 16th century via India and gradually 4 When looking at these methods one can easily imagine that the production of Indigo was considered to be an evil-smelling trade. O H N N H In 1880 Adolf von Baeyer succeeded in carrying out the first synthetic production of Indigo. In the year 1897 the “Badische Anilinund Sodafabrik“ in Ludwigshafen - which is nowadays called BASF - was able to carry out an industrial-scale production of the Indigo dyestuff for the first time. A few years later this synthetic dyestuff replaced the Indigo coming from British-India almost completely. As was already mentioned Indigo is a dyestuff insoluble in water. In order to be able to apply it on cotton it must be transformed into a water-soluble form. Similar to the former production of Indigo this is done by reducing the dyestuff (ill. 4). In practice this is nowadays carried out with sodium dithionite or hydroxiacetone in the alkaline range. O Indigo Oxidation Reduction HO H N N H OH Water-soluble leuco form of Indigo Ill. 4: simplified description of the reduction/oxidation of Indigo In former times dyeing with Indigo was carried out in wood or metal vats, normally in rope form. (ill. 5). 5 Ring spinning X-Cones Rotor spinning Ball warper Rope Creel Indigo – Continuous dyeing Warp size impregnation Weaving Control Long chain beamer Aftertreatment Sanforizing Ill.6: Indigo Rope Dyeing When dyeing according to the rope dyeing or cable dyeing method (Ill. 6) 350 - 400 warp threads are bound on the ball warper to very thick cables of 10 000 - 15 000 m length. On the continuous dyeing installation, 12 to 36 cables are led side by side, wetted, dyed and dried after the dyeing process on cylinders and put into cans. Then the cables are dissolved to warps on the long chain beamer. The warps are added to the sizing machine, sized and then led together to warp depending on the total numbers of threads. In practice, this method has proven to be very good through obtaining an optimum indigo dyeing. However it is important that the cables have a constant tension in order to avoid warp stripes. The disadvantage compared to other methods is that yarn breakages do occur more often. Size of the dyeing unit is between 60 - 80 m. Normally, 6 dyeing vats are in use. There are nevertherless variations with 3 to 8 dyeing vats. Ill. 5: Indigo sample dyer As very clearly visible on the above picture, at the bottom side of the rope the water-soluble Leukoform of the indigo is yellowish and on the side of the rope oxidized with air the indigo blue can be seen again. Nowadays, yarn dyeing with indigo is done continuously. Here the various dyeing processes with different concentrations of chemicals as well as the subsequent yarn sizing exert an influence on the quality and the appearance of the ready fabric. There are three processes in the practice for continuous dyeing: • Rope Dyeing • Slasher or Sheet Dyeing • Loop Dyeing 6 parallel next to each other. These are much smaller compared to the rope dyeing machines. Another advantage is that the cables don’t need to be open after dyeing. Moreover, each yarn wets much faster and in this way reduces the dipping and wetting times during dyeing. All in all, each thread has a larger surface compared to a dyeing cable and this requires somewhat more hydrosulphite to prevent a premature oxidation of the indigo. Rotor spinning Ring spinning Weaving X-Cones Control Ball warper Singeing Sanforizing Ill. 7: Indigo Sheet or Double Sheet Dyeing (Slasher Dyeing) When dyeing according to the sheet dyeing method, instead of cables the warp threads are fed to the machine Air passage Beam carrier Wetting Indigo-dyeing Ill.8: Loop Dyeing 1 for 6 7 Rinsing baths and sizing Whereas during rope and sheet dyeing the garns are always led in succession to the dyeing baths, the fabric of the loop dye method (Ill. 8) is led several times through the same dyeing bath. The machine is then much shorter and the hydrosulphite consumption is lower. Depending on the number of dyed passages and the concentration of indigo in the dyeing vats, different dyeings of the yarn result (Ill. 9). 3 g/l Indigo Ill. 10: Fibre cross-section of a yarn dyed with Indigo 1 passage The sizing process follows the dyeing process of the yarn, this is already visible by the machine sequences and is necessary to stabilize the warp thread against the high mechanical stress while the weft thread is being fed. For sizing the warp, PVA, CMC and acrylate sizes are used besides starch-containing products. 2 passages 4 passages 6 passages 6 g/l Indigo 4 passages After sizing, the dyed warp is woven with the non-dyed weft yarn. About 2/3 of all weaving machines in the world for denim are Sulzer Rüti Projectile weaving machines (Ill. 11). 6 passages Ill. 9: Indigo dyeing with various passages and dyestuff concentrations The dyeing methods described here do not allow a total penetration of the dyestuff during the short dyeing time and give the desired and necessary ring dyeing important for the jeans effect (Ill. 10) Ill. 11: Sulzer Rüti Projectile weaving machine 8 To achieve a finished width between 150 and 156 cm, weaving machines with a reed width of 160 to 167 cm are used. The speed of the weaving projectile can go up to 1 430 m/min and this complies with a speed of 86 km/h. 6 - 8 oz 9 - 11 oz The classical denim consists of a 3/1 side twill (Ill. 12). In succession three and one weft threads are put under a weft thread. Staggered by one warp, the typical twill with one degree from below left to above right, also called „Right-Hand-Denim“ results. Ill. 13: Summary of various denim qualities 12 - 14 oz 14, 5 - 16 oz very light denim for shirts light denim for trousers of summer quality medium denim for trousers, standard quality heavy quality, socalled bull denim, mostly for jackets Trousers and other clothing are manufactured with the denim material. With help of a pattern computer all parts for one trouser are made and then either printed by plotter on paper, cut and then the pattern is put on the fabric or fed directly to the cutting machine. Up to 30 pieces are required for a normal five pocket jeans. To cut each piece, 50 to 70 layers of fabric are placed on top of each other by a laying-up machine. This machine then saws all pieces in accordance with the pattern. Then the trousers are sewn together by the seamtresses. Each seamtress is specialized in a certain part of the trousers, e.g. pockets, front part, belt loops etc. The entire sewing process for one pair of trousers takes about 10 minutes. Ill. 12: 3/1 Twill weave Different kinds of finishing processes can follow after weaving depending on what the clothier wants. The denim is usually brushed directly after weaving to remove the fibre fluff from the weaving process. The fabric is also stretched and sanforized to minimize the crosswise and width shrinkage. Further Processing The first jeans trousers went directly from the sewing room to the shops and were stiff as wood. This remained so up to the beginning of the seventies. The first thing after buying a pair of jeans was to jump into the bath tub with the new jeans. The „shrink to fit“-treatment made them fit exactly to body form. Depending on the yarn thickness and weaving density, denim is divided up into various weight classes. This weight class is expressed in onces, whereas one English once (oz) is 28.35 g. The weight chosen depends on the manufactured article (Ill. 13). 9 The right look needed several household washings. Washed out jeans were „good looking“ and individual because almost every pair had its own look. Not to forget the first bleaching trials with toilet cleaning agents that left back non-removeable traces in the bath tub. The so-called „used-look“ was asked for and washing companies that gave raw trousers an artificial ageing process were jumped out of the grounds by the dozen. In these factories the trousers were given a full-step treatment like desizing, several washings and bleaching. Ill. 15: Lapauw in deloading position The pumice stone This is done today in over dimensional big washing machines, so-called drum washing machines (Ill. 14). The capacity of such drum washing machines can be up to 200 kg fabric which complies with about 250 trousers depending on the sizes. Most common are however batch sizes of approx. 150 trousers. Towards the end of the 70ies, pumice stones were discovered to accelerate the ageing process of indigo-dyed parts. No one exactly knows if the Japanese or the English first created the „stone-washed look“. The pumice stone is a magmatic extrusive rock. It originates from the very gasy beginning phase of a volcanic eruption. when the outer crust is thrown out in the atmosphere quite far. Its origin is up to 15 000 years back depending on the region. Most of them originate from Greece, Turkey, Iceland and small quantities can be found on Tenerife, the Azores, Philippines, Indonesia, China and Japan, Ecquador, Mexico and USA. Looking at where these pumice stones come from, you can imagine how different each character is. Abb 14: Lapauw drum washing machine Pumice stones have the following chemical composition: Some of these washing machines can be tilted to the front with running drum for emptying (Ill. 15). 10 partially separated: the undyed inside of the fibre comes to the surface. Moreover, the surface gets a softer handle through the mechanical process with pumice stones. 55 - 75 % Silicium oxide 10 - 16 % Aluminum oxide 3 - 6% Sodium oxide Portions of potassium oxide, calcium oxide und iron oxide How many stones are used for the ageing process of the trousers depends on the desired effect. Usually, the normal to double quantity of pumice stones is used with regard to the fabric weight. Treatment with pumice stones also brought some disadvantages. The sheets built in the drum washing machines had a high abrasion. During the beginning phase it did happen quite often that a batch of jeans was taken out of the machine that was totally torn from the ripped sheets. Large amounts of sludge together with fibre residues and indigo pigments accumulated during treatment with pumice stones that had to be disposed. Deloading the machine after stone treatment was very difficult because stones and their split off remainders were all over and had to be removed from the trousers. This was mostly done by hand, sometimes de-stoning units are applied. Last but not least, pumice stones are a natural raw material and their occurrence is limited. Through the gases originating during stone formation, a foam-like and porous structure was formed. These pores again have very sharp edges which give the stone its abrasive property (Ill. 16). Ill. 16: Turkish pumice stone, original diameter approx. 5 cm The pumice stones give the jeans trousers during the washing process the desired appearance in much shorter time as if it were washed many times. Depending on the application field, pumice stones with a 2 to 3 cm diameter are used for finer denim qualities, e.g. shirts. The common size for normal denim qualities is between 3 and 6 cm diameter. At the end of the 80‘s the progress in biotechnology made it possible to apply enzymes for enzymatic stonewash. The trousers must first be indigodyed to get a stone-washed look. The indigo dyeing of the yarn only takes place in the outer area, as already described. During treatment in a machine with pumice stones, the outer most layer of the yarn is 11