Category: denim

  • Reach Out To Denim Mills, Brands, Retailers ,Manufacturers And More – Worldwide !

    Denim Professionals Denimsandjeans.com is probably the most frequented site on the net for denim supply chain professionals from mills, brands , retailers , manufacturers around the world (hope we did not sound pompous– just a little proud..!) . We are opening some new sections on our site where the companies could advertise themselves  and make themselves  and their products visible to our discerning visitors . These places on our site are :

    a) Sidebar : We have one slot available on the sidebar which enables a company to be visible to all the visitors on our site. This is probably the most valuable location available on the site.

    b) Denim Mills Directory : Have you tried making the following searches on Google ?

    You would have found our ‘Denim Mills Directory’ page coming on the top. These are just some of the possible searches and effectively if a buyer is searching for a denim mill anywhere around the world, they would land on this page . With a  large number of denim mills around the world listed here , the buyers are able to reach their desired mills. But how would it feel to be on the top of this world list of denim mills and get the  first and immediate attention of the buyers/visitors. Well, the slot on this page will enable one denim mill to have the right to first being viewed and visited and to be on the top of the Denim Directory . Indeed a cool place for a mill to be !!

    c) Denim Brands : This page is again one which we are proud of as it is being continuously loved and listed  as a top page to visit for finding about denim brands worldwide.  We feel happy that many visitors searching  looking for accurate information on denim brands are able to find it here. Try searching ‘Top Denim Brands’  , or ‘Denim brands in USA’ , Denim brands from Japan and you will land up here . There is one slot available on this page.
    As we go further deeper into this section , we give details on denim brands worldwide through this section and details on individual brands look like this – click here. With almost all top denim brands worldwide finding similar  pages in our  directory , we are offering a single slot on all of these pages ..

    d) Denim Collections : What if you wanted to have a look at denim collections from some top brands worldwide for S/S09 and A/W’ 10 and S/S’09.. Either search for it on google one by one or just reach this page and find links to these collections. In any case ,  if you search for denim collections on Google  , you are going to reach here  !  Again , we are offering one slot on this page.

    e) Under Articles : We have one slot available for denim companies who might want to be visible to our visitors at the end of ALL ARTICLES on our site. Not a location which any visitor would miss to notice !

    For more details on terms and rates  visit this page or email us  by clicking here .
    And before I forget to mention, we will also be shortly starting the facility for creating a dedicated page for those who want to be more visible on our site. This page will be totally dedicated to that company and shall list out details on the company and display its products too! But only denim industry related companies shall be invited to join …..

  • Martelli Europe Presents Latest Vintage Denim Washes

    image Martelli Europe is one of the most reputed washing laundries around the world and brings out specialized washes at various times. The company is highly focused on contributing to new developments which result in environment friendly techniques . I spoke to the Managing Director of Martelli Europe – Mr. Mauro Angelini – regarding the same and he was quite emphatic on the contribution  of new  vintage wash developments which may help to reduce CO2 emissions and contribute in other ways to make them more environmentally sustainable compared to traditional washes..

    What are the new developments that Martelli is presenting currently ?

    We are currently working on several research levels. There is what we do for our customers and there is what we do for us not to "flatten". In this case we are studying the washing more environmentally sustainable in the sense that it involves a lower CO2 emissions, because they use less energy. It is not a simple process, we are working primarily with suppliers of chemicals like Garmon, in order to reduce CO2 emissions with washes and finishes using cold temperatures. Then, as always, we work hard to offer our "vintage effect" which is always greatly appreciated by all customers. Regarding dyeing even here we are from several years an avant-garde cold-dye.

    Many brands and retailers have banned sandblasting. What are the new technologies that are being used for achieving similar results ? Are these technologies viable ?

    Regarding sandblasting there is to say that in Martelli Europe we have always managed to propose the same or almost the same effect, without recourse to sandblasting. We are aware of the dangers which involves blasting , also we have to say, it is greatly reduced in new sealed implants the risks for operators. However, our thinking is that every process under high pressure produces dust, this sooner or later go airborne and is filled by someone. I do not think there is a powder that protects worker health, on the contrary, there are dusts that cause silicosis and others that cause asthma and other problems. I wonder if you simply replace the sand with vegetable or metallic abrasives, powder in the air remains. Similarly, using type solutions of carbon dioxide ice, certainly don’t help the environment and costs that do not believe customers want to endure. We go forward on our way, trying to use the technologies we have available. Customers appreciate our approach.

    I hear that you are implementing the SA 8000. Can you tell us more about the same ?

    It is true Sandeep and thanks for the question, we’re starting with the SA8000 which is the last after the ISO14001 ISO 9001 the OHSAS18001 we already have with the UKAS. Even here we are following with consistency in the way of quality, total quality. North European customers especially appreciate the fact that we have certifications, with SA8000, some multinational companies can forgo to make the social audit direct, as there has been announced by one of these. We are a company who has care of environmental issues but also of its employees.

    How is the denim market in terms of washing requirements? Do you see any difference in the current market  requirements compared to last year ?

    There is a growing trend to ask three-dimensional finishings (3D) with resins, then there is always required the vintage effect is probably our strength. As regards fabrics, in the summer collections all customers have a model with cotton stripes fabric.

    Are the brands trying to save on washing to reduce the cost of their garments keeping in view the increased cotton prices ?

    It was as a rule attempt to reduce costs with suppliers. Some young or inexperienced buyers sometimes tends to overdo it and it is how to cut the branch where you’re sitting. Now this trend it is slowly disappearing, the world is changed a little. The relationship with suppliers today it is not only “cost-money” it should be strategic in terms of partnership. The most experienced buyers and sourcing managers, remember that we (all supply chain)are clothing fashion industry. We cannot copy the speculative and short-sighted attitude of certain finance, particularly now after we’ve seen disasters that brought us the crisis of 2008. Today in clothing from fabric to the laundry, we see many closures and few openings, I don’t  think it is still the case to cut costs.

    Here are some details on the vintage washes that Martelli is presenting :

    SOYLENT GREEN – ECO

     soylent green eco denim wash

    Wash Details :
    KURABO FABRIC: SW STONE WASH + COLD DYEING = ECOLOGICAL TREATEMENT DUE TO THE TEMPERATURE SAVING:
    * BY USING COLD STONE WASH IT RESULTS A SAVING OF 30 ° C, WHICH ALSO REPRESENTS A SAVING OF 3 m³ CH4 (METHAN ) OUT OF BURNING = APPROXIMATELY 5.7 Kg OF CO2 EMISSION IN THE AIR
    * BY USING COLD DYEING IT RESULTS A SAVING OF 30 ° C, WHICH ALSO REPRESENTS A SAVING OF 3 m³ CH4 (METHAN ) OUT OF BURNING = APPROXIMATELY 5.7 Kg OF CO2 EMISSION IN THE AIR

    CROCKER – ECO

    soylent green eco denim jeans wash

    Wash Details :

    KURABO FABRIC: SW STONE WASH + COLD DYEING + WORN EFFECTS MADE 100% MANUAL = ECOLOGICAL TREATEMENT DUE TO THE TEMPERATURE SAVING:
    * BY USING COLD STONE WASH IT RESULTS A SAVING OF 30 ° C, WHICH REPRESENTS ALSO A SAVING OF 3 m³ CH4 (METHAN ) OUT OF BURNING = APPROXIMATELY 5.7 Kg OF CO2 EMISSION IN THE AIR
    * BY USING COLD DYEING IT RESULTS A SAVING OF 30 ° C, WHICH REPRESENTS ALSO A SAVING OF 3 m³ CH4 (METHAN ) OUT OF BURNING = APPROXIMATELY 5.7 Kg OF CO2 EMISSION IN THE AIR

    KOJAK –ECO

    kojak eco denim wash

    Wash Details :
    KURABO FABRIC: ECOLOGICAL VINTAGE GAINED THROUGHT AMPLE WATER AND TEMPERATURE SAVINGS = 3D EFFECT (3D EVOLUTION) + MULTIPLE MANUAL WORN EFFECTS + COLD STONE WASH :
    * BY USING COLD STONE WASH IT RESULTS A SAVING OF 30 ° C, WHICH REPRESENTS ALSO A SAVING OF 3 m³ CH4 (METHAN ) OUT OF BURNING = APPROXIMATELY 5.7 Kg OF CO2 EMISSION IN THE AIR
    * BY COMBINING COLD STONE WASH WITH NEUTRALIZING IT RESULTS A SAVING OF APPROXIMATELY 16L OF WATER / UNIT
    * BY USING RESINS WHICH POLYMERIZE AT 90° C INSTEAD OF 140 ° C, IT RESULTS A SAVING OF 3 m³ CH4 (METHAN ) OUT OF BURNING = APPROXIMATELY 5.7 Kg OF CO2 EMISSION IN THE AIR
    * THIS TYPE OF RESINS DOES NOT CONTAIN FORMALDEHYDE

    DET STAVROS

    image

    Wash Details :
    KURABO FABRIC: SW STONE WASH + MULTIPLE WORN EFFECTS / COLOUR MADE 100% MANUAL:
    * BY USING COLD STONE WASH IT RESULTS A SAVING OF 30 ° C, WHICH REPRESENTS ALSO A SAVING OF 3 m³ CH4 (METHAN ) OUT OF BURNING = APROXIMATELLY 5.7 Kg OF CO2 EMISSION IN THE AIR

    RIZZO

    rizzo denim washing martelli

    Wash Details :
    KURABO FABRIC – AN OLDER TYPE OF TREATEMENT MEANING DRY DECOLORATION, BUT COMBINED WITH NEW PROCEDURES SUCH AS 3D EFFECTS CAN GENERATE INTERESTING RESULTS, MAINLY WASHINGS WITH A MORE AGGRESSIVE VISUAL IMPACT
    ** THIS TYPE OF PROCESS ALSO HAS AN ECOLOGICAL ASPECT DUE TO THE FACT THAT IT REDUCES THE WATER CONSUMPTION WITH APPROXIMATELY 16 L / UNIT, UNLIKE A DECOLORATION MADE WITH A NORMAL WASHING MACHINE.

    You can just watch all these presentations in a slideshow below :

    Also, here is a cool video from Martelli showing some of their vintage wash processes .

    Want to contact Mr Mauro Angelini ? Email here

  • History , Chemistry And Application Of Indigo Dyes

    Bluconnection – an innovative indigo dye manufacturing company from Singapore has compiled a comprehensive compendium about the history , chemistry and application of Indigo dyes. We are producing some extracts from this compendium . Also show is the complete presentation in a slideshow under the article and it can also be obtained in  PDF form Free by email from Paul Cowell of Bluconnection.

    Indigo History

    The roots of indigo go back into the stone age when our ancestors used indigo in cave art and for painting their bodies. for at least 6,000 years indigo has been used as a dye, for example the colouration of textiles. the oldest evidence for this was found during excavations in the indus valley between bricks forming a small vat in the ground. it is suggested that this is why we call it indigo, a greek word meaning “coming from India.”
    There are many plants containing the precursor of indigo, before indigo was
    synthesized, it was extracted from these plants – in the beginning probably just by chewing them. historically, indigo maintained it’s place since it was the only blue dye available and still today, after more than 150 years of organic chemistry and quite a few competitive dyes of blue colour, it is still the most efficient blue dye or pigment. in fact there is no other substance that creates such intensive blue colour with such few carbon atoms in its molecule.
    In the high and late middle ages – about 500 to 1000 years ago – the most
    important dye for black, blue and brown shades was gained from a plant called “dyer’s woad” (isatis tinctoria). woad was grown in England and Germany and the areas and towns involved in growing and trading woad became extremely wealthy. many rules and regulations gave privileges to those communities in order to maximize and maintain their earnings from woad.
    This dye was not called indigo. Indigo only came to Europe later during the modern age. Although today we know that both dyes had the same chemical  structure. In the course of increasing overseas trade, colonialism and slavery, indigo was produced on large plantations in subtropical regions, e.g. in India and along America’s Atlantic coast. this indigo was extracted from a plant named “indigo fera tinctoria”. It was purer and gave a more brilliant shade. despite the ongoing privileges protecting the woad industry, this indigo gained more and more market
    share. in Nurenberg it was written that even the death penalty was imposed on those found guilty of having used indigo. nevertheless, woad had nearly disappeared by the second half of the 19th century. by that time the global annual consumption of natural indigo had reached 5,000 metric tons.
    Indigo had largely contributed to the wealth of the companies and patrician
    families involved in overseas trading. due to this, the pioneers of organic chemistry were challenged to find a way to synthesize indigo. In 1883 Adolf von Baeyer, a German professor and winner of the 1905 nobel prize in chemistry, discovered the chemical structure of indigo. based on this work, synthetic indigo production was developed at Badische Anilin & Soda Fabric (BASF) and started in an industrial scale. within only a few years synthetic indigo almost completely replaced the natural indigo imported from overseas.

     image
    imports and exports of indigo in the German Empire

    The production and sales of synthetic indigo followed the graph of a typical
    product cycle. It grew during the first years and declined later because the
    chemists had developed other dyes with better yield and superior fastness
    properties. having understood chemically the principle way of applying indigo, reduction to a dye and oxidation to a pigment on the fiber, a number of other vat dyes were synthesized. however, indigo never has been defeated and after decades as a niche product it came back as the dye for denim in the late 50’s of the last century.
    Production of synthetic indigo had it’s revival during the second half of the last century and indigo has become the most important textile dye.

    • Jeans fashion has reflected the change towards a more liberal attitude.
    • Work wear. originally gold seekers, later cowboys, craftsmen etc.
    • Less formal clothes required and appreciated
    • James Dean Effect

    In the 50s BASF was prepared quite well for this hype. Nevertheless BASF’s indigo capacity could not meet the huge global indigo demand during the 60s and 70s. The increasing prices encouraged quite a few competitors to invest in indigo production, particularly in China. it is said that in Hong Kong an indigo drum could be sold for a lot of money. Former sales managers tell about customers who issued blank cheques hoping to get hold of some extra kilograms of indigo.Huge indigo production capacities had been built up in China by the middle of the 90s. with a total capacity around 100,000 tons for a global indigo market of ~30,000 tons. Today we estimate a global indigo market consumption of ~60,000 tons. Due to excess capacity for synthetic indigo this market became an oligopoly during the 1990s. lower and lower prices made the smaller producers disappear.
    Indigo by nature has a number of unique features making it successful:

    • it supplies favored shades from black to navy to sky blue.
    • these shades are balanced – not too brilliant or artificial and not too dull.
    • as a pigment it would not participate in metabolism making it very safe for human contact, in fact indigo is used as food dye and as medical indicator applied intravenously.
    • it is “designed” to exist as reduced soluble form during dyeing and as oxidized form as blue pigment.
    • it’s soluble form is not sensitive to water hardness and this allows the dyeing of greige or minimum pretreated cotton.

    Shown below is the complete presentation and as mentioned above you can also get a Free PDF file by sending an email to Paul Cowell

  • Common Defects In Denim Jeans Sewing

    denim-seam-inequalitiesAmerican and Efird – has listed out some of the most common seam inequalities in the manufacturing of denim jeans . The company lists out the defects and suggests solutions for removing these defects. We are summarizing the results from A & E  below :

     

    1.BROKEN STITCHES – NEEDLE CUTTING

    Description : Where the thread is being broken where one seam crosses another seam (ex: bartacks on top of waistband stitching, seatseam on top of riser seam ) resulting in stitch failure.

    denim stiching

    jeans sewing

    Recommended solution by A & E :

    • Use a larger diameter thread on operations
      where the thread is being cut.
    • Make sure the proper stitch balance is being used. On a chainstitch seam on denim, you normally would like to maintain a 60%/40%
      relationship of Needle thread to Looper thread in the
      Seam.
    • Use needles with the correct needle point.
    • Change the needles at regular intervals on operations
      where the Needle Cuts are occurring frequently.
    • Use a higher performance  Perma Core or D-Core thread.

    2.Broken Stitch – Abrasion :

    Description : where the thread is broken during stone-washing, sand blasting, hand sanding, etc.  Broken stitches must be repaired by restitching over the top of the stitch-line.

    denim defects denim sewing

    Recommended Solution :

    • Use a larger diameter thread on operations where
      excessive abrasion is occuring  (ex: use T-120 on
      Waistband
      );
    • Make sure stitches are balanced properly.
    • Use a Magic air entangled thread in the looper due to its lower
      seam profile making it susceptible to abrasion
      (ex: use T-90 or T-135 Magic in loopers of the Yoke, Seat
      and Waistband seam);
    • Monitor the Finishing Cycle for compliance to specs.

    3. Broken Stitches : Chemical Degradation :

    image

    Description : where thread is  being compromised by the chemicals used during laundering resulting in loss or change of color and seam failure.

    • It is recommended to go to larger thread sizes when the
      Denim Garments will be subject to Harsh Chemical
      washes.
    • To achieve the best laundering results make
      sure that the water temperatures and PH Levels are
      correct and that the proper amounts and sequence of
      chemical dispersion are within guidelines.
    • Make sure the garments are being rinsed properly to neutralize the
      chemicals in the fabric.
    • Monitor the drying process, cycle times, and temperatures to make sure they are correct so that the best possible garment quality can be
      achieved.

    4. Unravelling Seams :

    denim sewing denim stitching

    Description : where either the stitch has been broken or a skipped stitch has
    occurred. This will cause seam failure unless the seam is Restitched.

    Recommended Solution :

    • This may include going to a higher
      performance thread designed to minimize sewing
      interruptions.
    • Observe sewing operators for correct
      material handling techniques.

    6. Sagging or Rolling Pockets :

    Description :  where the pocket does not lay  SAGGING OR ROLLING POCKETS  flat and rolls over after laundering.

    denim stitching

    Recommended Solution :

    • Make sure the sewing operators are not holding POCKETS
      back
      excessively when setting the front pocket.
    • Make sure the hem is formed properly and that excessive
      fabric is not being being put into the folder
      that will cause
      the hem to roll over.
    • Check to make sure pocket is cut properly and that pocket curve is not too deep.
    • Use a reinforcement tape on the inside of the pocket that may
      help prevent the front panel from stretching along the bias
      where the front pocket is set.
    • The type and weight of denim, along with the fabric construction, may contribute to this problem. Contact your fabric supplier for assistance.

     

    5.Skipped Stitches

    Description: where the stitch forming device misses the
    needle loop or the needle misses the looper loop. Skips are usually
    found where one seam crosses another seam and most of the time
    occurs right before or right after the heavy thickness.

    denim stiching jeans stiching

    Recommended Solution :-

    • Use corespun thread.
    • Use minimum thread tension to get a balanced stitch.
    • Use the ideal foot, feed and plate that helps to minimize
      flagging.
    • Training sewing operators NOT to stop on the
      thickness.
    • Make sure the machine is feeding properly
      without stalling.
    • Make sure the machine is not back-feeding.

    6. Ragged – Inconsistent Edge

    Description : where the edge of the seam is
    either extremely “ragged” or “rolls” inside the stitch.

    jeans edge

    Recommended Solution :

    • Make  sure the sewing machine knives are sharpened and
      changed often.
    • The knives should be adjusted properly in relationship to the “stitch tongue” on the needle plate to obtain the proper seam width or width bite.

    7. Wavy Seams On Stretch Denim

    Description : where the seam does not lay  flat and is wavy due to the fabric stretching as it was sewn or during subsequent laundering and handling operation.

    image

    Recommended Solution : 

    • Use minimum presser foot pressure.
    • Instruct sewing operators to use proper handling techniques and not
      stretch the fabric as they are making the seam.
    • Where available, use differential feed to compensate for the
      stretch of the fabric.

    8. Ropy Hem

    Description: is where hem is not laying flat and is skewed in  ROPY HEM
    appearance .

    image

    Recommended Solutions :

    • Instruct the sewing operator to make sure they get the hem started correctly in the folder before they start sewing.
    • Also, make sure the don’t hold back
      excessively as the seam is being sewn.
    • Use minimum roller or presser foot pressure.

    9. Twisted Legs :

    Description : is where the sideseam twists around to the front   of the pant and distorts the appearance of the jeans .

    twisted legs jeans

    Recommended Solution :

    • Instruct the sewing operator to
      match the front and back properly so they come out the
      same length. Sometimes notches are used to insure proper
      alignment. They should NOT trim off the front or back with
      scissors to make them come out the same length.
    • Make sure the cut parts are of equal length coming to the
      assembly operation.
    • Check fabric quality and cutting for proper skew.
    • Make sure the sewing machine is adjusted
      properly for uniform feeding of the top and bottom plies

    8. Disappearing Stitches in Stretch Denim

    Description :  is where the  thread looks much smaller on seams sewn in the warp direction than in the weft direction of the fabric

    jeans stitching

    denim jeans stitching

    Recommended Solution :

    • Use a heavier thread size (T-120,  ON STRETCH DENIM
      T-135, T-150) on topstitching.
    • Go to a longer stitch length  (from 8 to 6 spi). 3) Make sure the thread tensions are as loose as possible so the thread sits on top of the
      fabric rather than burying in the fabric on seams sewn in
      the warp.

    10. Thread Discoloration after Laundry

    Description : is where the thread  pics up the indigo dyes from the fabric giving the thread a ‘dirty’ appearance. A common discoloration would be the pick-up of a greenish or turquoise tint.

    denim stitching

    Recommended Solution :

    • Use thread  with proper color fastness characteristics.
    • Correct PH level (too low) and Water Temperature (too low) during
      laundry.
    • Use the proper chemicals & laundry cycles.
    • Use Denimcol PCC in wash or similar additive.
    • Do Not overload washers with too many garments at one time

    Need further  info on denim stitching , visit A&E website or contact them.

  • Rope Dyeing Vs Slasher (Sheet) Dyeing

    This is a guest post by Harry Mercer

    Until 1915, most Indigo dyeing was conducted in skein machines for cotton or loose fiber dyeing for wool. Skein dyeing of Indigo is still the best method for dyeing Indigo on very fine yarns for the delicate high-fashion fabrics. In 1915, the first rope dyeing machine appeared and only in the 1970’s was sheet dyeing introduced. The relative advantages of rope as opposed to sheet Indigo machines is a common subject of debate. Based on my 30 years of experience in this area, including as a consultant in about 40 denim operations worldwide, here are some basic observations that I have made in companies that had only sheet or rope dyeing, but also in many denim companies that employed both. These evaluations included mass-balance studies, benchmarking, weaving efficiency and overall fabric quality.

    A. Lower consumption of reducing agent per kilogram of yarn.

    The primary reducing agent utilized in Indigo dyeing is sodium dithionite, commercially known as sodium hydrosulfite. The amounts of this reducer that are consumed in Indigo dyeing are greatly in excess of what is necessary for the Indigo dyeing itself. In explanation, in order to reduce 100 kilograms of pure Indigo so that dyeing can proceed, only about 66 kilograms of 100% hydrosulfite are required for the basic reaction. The amount of hydrosulfite actually consumed in Indigo dyeing is often3 or 4 times this amount. There is often hydrosulfite wasted incurred in the initial mixing of the stock mix, due to excessive stirring or concentrations of hydrosulfite greater than 80 grams per liter which promotes anerobic decomposition.

    A great deal of hydrosulfite is lost because of contact with atmospheric oxygen at the surface of Indigo dye boxes as a result of aerobic decomposition. The surface losses of hydrosulfite are related to the volume and surface area of the dye boxes, with approximately 15% loss in larger Indigo boxes found on rope ranges and 50% or more in the smaller dye boxes found on sheet ranges.

    The scientific explanation for this phenomenon is related to what is known as Specific Surface Area (SSA). The greater the SSA (the quotient of the surface area and volume), the more rapidly the sodium hydrosulfite is oxidized. The time for half-oxidation (50% loss) is inversely proportional to the SSA, which means that decomposition is slowest in a large dye tank with a relatively small surface area. There are other factors involved such as the initial concentration of hydrosulfite in the dye boxes – a higher initial concentration decomposes more slowly. However the most significant source of loss is through surface contact and air brought into the dye tank by yarn.

    The instability of hydrosulfite in smaller Indigo boxes is also the primary cause of color variation in Indigo dyeing, which on rope ranges is much better controlled. It should also be noted that rope ranges have the advantage in regards to Cross Shade Variation(CSV), which refers to differences in color from side-to-side in the fabric. CSV is basically a result of dye circulation system design where the Indigo enters the dye box from the side instead of the front. In rope ranges that are designed with that style of circulation there is also some difference in the yarn color from to side-to-side, but unlike sheet ranges where the yarns are fixed in their final fabric position, the yarn ropes can be blended to remove the side to side effects. There have been some newer designs of Loop indigo machines which have greatly improved CSV.

    B. VERSATILITY IN DENIM PRODUCT DEVELOPMENT

    Rope ranges have been designed to apply the widest range of dyeing techniques. For example, the Spectrum Dye Machine available from Morrison contains features like additional steamers and drying sections that allow not only the standard dyeing techniques of sulfur bottoming and topping, but also consistent application of all other cotton dyes such as vats, reactives and directs in combination with Indigo or dyeing yarns with these dye classes only.

    Spectrum_single_thread rope dyeing

    Also available are specially designed dye boxes that allow the simultaneous dyeing of 2 different sulfur applications, such as one set of yarn with a sulfur topping and the other set without topping, or with only a sulfur color, which allows flexibility in production. Rope ranges are also easily adaptable for random effects such as space dyeing of yarn. With the rope design, yarns from different dyeings such as Indigo only and sulfur only, can be blended for producing stripe patterns.

    2-1_indigo_washer

    C. HIGHER PRODUCTION AND FABRIC QUALITY

    Common methods of operating Indigo machines have a damaging effect on yarn quality which results in very high warp breaks in weaving, lowering efficiency and increasing off quality. Yarn on the machines is made weaker as yarn tension increases. Sheet Indigo machines, because they are attached to size machines, have very high levels of yarn tension and therefore higher weaving breaks than yarn dyed on rope ranges. A yarn quality that would result in 10 warp breaks per million weft insertions without Indigo dyeing often will have around a break level of 200 with sheet dyeing, but as low as 15 if processed on rope machines. This is because tension on rope machines is much lower and can be easily controlled at very low levels.

    Another important cause of high weaving breaks in denim is dirty yarn – the cleaner the yarn the higher the weaving efficiency. This is because chemicals not washed from the yarn after Indigo dyeing result in bad sizing and lower protection of warp yarns. Wash boxes on rope ranges are typically more efficient than the smaller wash boxes on sheet ranges that use overflow washing methods. The importance of washing the yarn dictates that it is better not to apply softeners in the final box for rebeaming efficiency which is optimal though improved washing and moisture control after drying.

    The need for a separate rebeaming step in rope dyeing is often considered objectionable in rope dyeing, but this is actually an important advantage, since yarn breaks can be repaired at rebeaming resulting in higher weaving efficiencies. Yarn breaks from warping and dyeing cannot be repaired in sheet machines because they are passed directly from dyeing to sizing.

    D. FLEXIBILITY IN PRODUCTION

    Sheet ranges are usually limited to producing yarn for only 1 weaving set at a time. In a rope range, normally 12 ropes will produce enough yarn for a weaving set and because rope ranges do not pass the yarn directly to the size machine, from 1 to 50 ropes can be dyed at one time. Any combination of yarns can be processed for completely different fabric constructions at the same time and dyed with the same Indigo color. Also, rope ranges can be operated continuously without stopping, which avoids the waste of yarn which occurs when sheet ranges must stop in order to change yarn lots. Because the yarn is sized separately.higher priority fabric orders can be processed without delays resulting from the need to complete a dye set as with sheet dyeing.

    Rope Dyeing – Morrison

    imageThis is a guest post by Harry Mercer. Mr. Mercer has 30 years experience in the denim business including 3 prominent U.S. denim companies. He is an expert colorist for measurement and color matching as well as textile testing.

  • Levi’s : New Terms Of Engagement For Suppliers –On Social And Environmental Standards

    Levi’s is trying to touch new heights on the  ladder of corporate social responsibility by ensuring in various ways  that its suppliers adhere to practices which are good for the workers  and for the society as a whole. Since , Levi’s hardly has its own manufacturing left now, it is dependent on factories around the world in Asian , South American and African countries to make products for them . On the one hand, it increases the need to monitor and control these factories , but on the other hand , it also gives Levi’s the power to  affect the lives of people connected with these factories and of  the apparel industry as a whole . 

    While Levi’s recently announced its decision to ban Sandblasting in its factories to prevent harmful effects on its workers, it has now gone a step ahead and announced the new terms of engagement for its suppliers. The main idea behind this announcement is to move  beyond compliance to help improve the lives of workers in factories around the world. Under the new approach, the company will require contract factories to help make employees’ lives better by supporting programs for their workers that align with the UN Millennium Development goals.

    Levi’s President and CEO – John Anderson – announced at the recently held CERES conference these new terms in his speech. Here is the complete speech – its quite long . I tried to cut it short – but was difficult to do so without his address losing some of the meaning and intent . The speech is quite an honest one and shows that the company is strongly focused to make these terms work . However, the challenge for the company would be to balance the demand for getting products at the right price vs that of getting

    “ John Anderson :

    I’m honored to be invited to speak to you here today
    For years, CERES has helped advance the debate about what it means to be a
    responsible company.  All of us at Levi Strauss & Co. have felt the impact of your work, and we have been honored to partner with you. 
    We’ve been particularly proud to be a founding member of BICEP – Business for Innovative Climate and Energy Policy – the CERES-led business coalition providing the business case for innovative climate and energy policy to ensure U.S. leadership and competitiveness. 
    CERES has furthered that leadership with the Investor Business Roundtable
    announced this morning.  We know the success of this Roundtable will depend on the pledges from companies in this room. Levi Strauss & Co. is proud to heed this call with a commitment to action in our supply chain.  My remarks today will outline this approach.  

    I want to look ahead – ahead at what I propose ought to become the new apparel industry standard of social, economic, and environmental sustainability.  As I will explain, this new standard isn’t just for apparel companies like ours. It establishes a new, higher set of expectations that investors, activists, and governments should all promote.
    It applies to all of us in this room – whether you work for an auto manufacturer or a technology company – or you have vendors that employ workers around the world.

    Twenty Years Ago: We Pioneered A New Standard

    For us at Levi Strauss & Co., this is a good time to think about raising the bar.  Twenty years ago, we established a set of labor standards for our suppliers  around the world. We called them our Terms of Engagement
    We believed – and we still do – that a successful global company must set a high standard for ourselves and the factories we do business with around the world.  So we took the labor, health, safety, and environmental standards we used in our owned and operated factories and effectively told our partners:  “this is now your standard – regardless of where you operate.”
    To put it mildly, we didn’t win much applause initially.  Some of our competitors snickered.  They thought that it was just the “do gooder” Levi Strauss & Co. being impractical and idealistic.

    Many predicted we would go out of business because we were asking global
    suppliers to do what critics considered was beyond the scope of companies: To demand their supply chain treat their workers with dignity, respect, and fairness and to run safe, clean factories. 
    And, of course, there was also a real dollar cost to this decision. Both to us and to our suppliers. Our competitors weren’t the only skeptics. Many investors and business leaders scoffed… asking: “why should a company take on a burden that was the  government’s responsibility?”
    But, two decades ago, the leaders of our company, in particular our then-CEO Bob Haas, wouldn’t be swayed.  They wouldn’t be pressured by the critics.  And they were heartened by the support they received from labor and human rights leaders – including some of you here today –who believed that a responsible and successful global company was obligated to take this step.
    In the broadest sense, our Terms of Engagement worked in ways bigger than we ever imagined.  Not only did more than 90 percent of our suppliers accept them, we discovered that we’d set a new standard
    Before long, our Terms of Engagement became the new normal.  Almost every apparel company with a global supply chain established their own version.  Compliance became the new yardstick for measuring how responsible companies performed.  Before we knew it, independent watchdog groups were monitoring us, keeping check lists, and holding us accountable. In fact, many in this room help keep us honest by asking the right questions on the ground every day.
    Five years ago, we disclosed our list of suppliers around the world.  That enabled labor and advocacy groups, the media, and other companies to help us identify 3 and address problems when they develop.  In this area, above all, transparency works.  It makes a difference when groups like Ceres demand it.

    The Limits of Compliance

    There is, of course, still much to do.  With factories in developing countries
    around the world, there were – and always will be – problems on the ground.  From the tragic factory fires in Bangladesh to abuses against migrant workers,  we still see setbacks.
    In fact, I think most of us would have to agree that any honest assessment of
    global compliance programs in our industry would give only a middling grade.
    While we’ve made progress in a number of areas over twenty years, the hard truth is: we haven’t made nearly enough progress on improving the everyday lives of the people who make our products.
    In fact, the reports we continue to receive about problems in factories should challenge us to update our Terms of Engagement for the next twenty years; to re-examine our current compliance approach. 
    Compliance has us focused – perhaps obsessively so – on two things: a standard of

    1. “do no harm” and
    2. factory-level monitoring and reporting.  

    We measure very well what our factory suppliers are doing – or not doing – to meet these global standards. But we pay less attention and devote fewer resources to the real, everyday outcomes for human beings.
    Many of us in the apparel industry are too familiar with the fire extinguisher story.

    • One of our compliance monitors noticed that a fire extinguisher was hung awkwardly on a factory wall with a slide that allowed it to move to different heights.  What was going on with the fire extinguisher, she asked.  “Well, one company says the fire extinguisher must be hung 2 feet off the floor.  nother brand requires it to be 4 feet off, and you want it 3 feet off the floor.”

    As you know, stories like this can be found all through supply chains in the
    developing world.  In some cases, good intentions have gotten smothered by compliance regimes. 
    A couple of years ago we surveyed our suppliers around the world.  We
    discovered that some of them were monitored an average of 25 times each year. Every two weeks, a monitor from another brand would come and check records, do a walk through, interview workers, and talk to management.And that was just the average!

    • Can you imagine – in your own organization – if an inspector came every two weeks to demand senior management do an audit?  And, during the audit, demanded slightly different corrective actions than those required two weeks earlier?

    You wouldn’t have time to make many of the requested corrections, much less do your work. I don’t want to minimize or trivialize the importance of monitoring, compliance, or  reporting.  I don’t think global companies or their suppliers should be let off the hook.  Absolutely not.
    But if our ultimate goal is to improve not just factory conditions, but to make a material difference to the people and communities in our supply chain, then we need a more holistic approach…a more human perspective.
    I want to be very clear on this point, because I don’t want to be misunderstood about the commitment at Levi Strauss & Co. to enforce fundamental standards of worker rights, health, safety, and environmental protection. 
    Our record, our history, and the recognition you have given us should leave no doubt on that front.  We will continue monitoring and working with our suppliers and others to improve compliance with our Terms of Engagement.
    Our New VisionBut we need to do more. 

    Today I want to share our vision for the next stage in the evolution of our Terms of Engagement.

    Going forward, Levi Strauss & Co. intends to propose a new approach in this
    arena.  In our view it is a higher standard and tougher standard.  But we also
    think it is a better standard.  Better for the employees who work throughout our supply chain.  Better for their communities.  And – I say this without apology –better for our business.
    Our new Terms of Engagement, to be spelled out in detail over the next year, will ask our suppliers and partners to do more.  Us to do more.  But it will also give all of us a new and more productive focus.
    Our intention is to build new requirements for our key suppliers that align with the United Nations Millennium Development Goals.  These goals – not merely compliance – ought to be the new standard of engagement, and the common objective for every company in our industry.
    These goals are known to everyone who has been active in global development.  They have been endorsed by every nation in the world. And they should be the philosophic underpinning of how we support the people who make our products.
    We intend to work with our suppliers to focus on several of the eight MDGs,
    because we believe the apparel industry is best positioned to help drive results on these.  Among them are:
     

    • eradicating extreme poverty and hunger
    • improving maternal and child health
    • combating HIV/AIDs, and other diseases
    • promoting gender equality and empowering women
    • ensuring environmental sustainability

    Following the rules and conditions of labor rights and workplace safety and health will continue to be an embedded part of the way we operate.  We have no intention of stepping back from our compliance requirements.
    But in setting our sights on alignment with the Millennium Development Goals, we are actually asking our suppliers to do more: We are going to find new ways to measure success by focusing on improving the actual living conditions of workers whose lives we touch.
    I know this all sounds a bit abstract – so let me give you an example of the kind of program we believe should be adopted in factories around the world.

    The Levi Strauss Foundation has been supporting a pilot program to increase financial literacy among apparel workers, developed by an NGO called Give to Colombia. This groundbreaking partnership provides financial training, matched with savings accounts and microenterprise development programs for workers in the  apparel industry in Medellin, Colombia. Workers receive education about family budgeting, assessing credit worthiness and understanding the importance of savings as a way to ensure their family’s future.Those who start a savings account receive access to government programs such as credit for low income housing, with preferential interest rates. It may seem counterintuitive that a company would work to require its suppliers to provide savings accounts for workers. But these programs generate real results in improving the lives of workers. This in turn creates stronger, more effective factories.

    Other programs we’d like to implement with our suppliers include access to
    HIV/AIDS education, and access to maternal and infant health services.  When it comes to the environment, we’re focused on setting targets for measurable reductions in material, energy, and water use by our suppliers.
    Programs like this are happening on various scales with companies around the world – but we’d like to be the first company to build them into our business model and contracts with factories around the world.
    And while we may be the first on this front, we don’t expect to be alone on this journey for long.  We know the world of global sourcing and manufacturing.  We know our industry colleagues want to find solutions that are good for their people and good for their business.  I am absolutely confident that they will see this integrated, forward-looking approach as a better solution. This vision – working with our suppliers to help make employees’ lives better by supporting programs for their workers that align with the UN Millennium Development goals – is admittedly, quite ambitious. 
    And like the Terms of Engagement we established twenty years ago, we do not believe this will be achieved overnight. How we will implement this vision We are clear about our vision.  But we would not be so arrogant to suggest we  have all the answers about the best way to create the metrics we need to drive  change.
    Making it work and persuading others to join us won’t be easy.  But we are
    determined to make it work.  We have to make it work.  That’s why we aren’t simply issuing a new rule book from San Francisco.   We’re proposing working with the experts in this room – as well as those outside
    it – to develop a public white paper with recommendations for action. And we’re making a commitment to start implementing these programs in our supply chain by this time next year.
    We’re going to begin with the CERES stakeholder engagement model and invite  a group of interested NGOs, brands and labor leaders to advise us.
    We’re also going to work very closely with our suppliers on the ground to make sure we’re creating local solutions that can be scaled up in order to really address the apparel industry’s most pressing social issues.
    And we’ll continue to seek advice from the Levi Strauss Foundation and other leading global organizations that have been doing work in the apparel industry for years. What we ask of you In addition to your advice and expertise, to make this work, we also need you to help raise awareness about this new standard. We can’t do it alone.  Progress will be incremental. And we will surely continue to have occasional problems that might be embarrassing.  Undoubtedly, with thousands of factories around the world, there will always be short-term supply chain issues.  But true to our history, we want to make our long-term commitment clear – and we want to honor our history of staking out new ground as pioneers.
    With your help, we hope it will trigger a sea change in the way Terms of
    Engagement evolve across industries.   The next twenty years are going to be very different for both our economy and the world.  We want to help shape that future.  To achieve it, we are convinced that a new approach to corporate responsibility  is needed. We are sure that if companies focus not just on the legal requirements, but on a broader vision of social, economic, and environmental sustainability, they will be rewarded. 
    Ultimately, we strongly believe that higher standards will drive better performance and results in our suppliers’ factories.
    Five years ago, the Levi Strauss Foundation partnered with Business for Social Responsibility to launch HER-Project, a woman’s health education program in factories in Bangladesh, China, Egypt, and Pakistan.  The program is touching more than 90,000 women in 65 facilities.
    The focus is on women’s health outcomes, helping factory workers connect to existing health care services nearby. A study found that for every dollar invested in building the capacity of factory health clinics, health education, and training, three dollars of return are realized in the form of increased productivity on the factory floor. Let me repeat that – one dollar invested provides three dollars in return

    • Greater concentration on the shop floor.
    • Less absenteeism. 
    • More production targets  met. 

    These are exactly the kinds of results socially responsible investors have told us we could achieve.  The workplaces of the 21st century will be stronger when workers have the tools to improve their lives.  When they are given healthy and safe workplaces, they become more productive, dependable, and efficient. We can demonstrate that investing in workers is what you do because, one: it’s  the right thing; and two: it yields profitable returns. 
    We see this as an indispensable component of a true sustainable growth story.  It is a business plan and an investment plan that will work.
    As investors and close observers of business, you know what we mean.

    So my message to you is: please join us.

    Help convince our industry and other industries that improving the quality of life ought to be the real touchstones for the next stage of activism and engagement. We need your help.  It will create better companies.  It will create a better world……”

    Here is  a small video which gives more insight into these new proposed terms of engagement:

  • Jeans Garment Dyeing with Sulfur Dyes

    This is a guest post by Harry Mercer

    Why Garment Dyeing?

    Garment dyeing is a method of dyeing fully-fashioned garments such as t-shirts, sweaters, dresses, stockings and jeans. In the conventional method of fabric manufacturing, fabric that has been pre-dyed (piece-dyed) is cut-and-sewn into garments.

    The conventional method has the advantage in terms of cost effectiveness of mass production of fabric in specific colors. The most significant disadvantage in the conventional approach is the economic risk of carrying a large inventory of limited styles or colors in a fashion market that is constantly changing.

    Dye Selection in Cotton Garment Dyeing

    The primary options for dyeing black in cotton garments are direct dyes, reactive dyes , pigments and sulfur dyes.

    Direct dyes

    • These  require very high dyeing temperatures, and large amounts of electrolyte such as salt for dyeing . Additionally, direct dyes, especially in dark shades, require a fixing agent to be applied at the end of the dyeing cycle for reasonable wash- and crock fastness. Directs offer the lowest dye costs per garment and are simple to apply.

    Reactive dyes

    • These dyes were chemically-engineered in the mid-20th century to provide a technique for dyeing cotton that was simple enough so that an understanding of dye chemistry was not necessary. Designed to be nearly “idiot-proof” in application, this class of dyes is highly favored in operations where costs and productivity are not considered important.

    Pigments

    • Pigments are primarily of interest in producing so-called “distressed look”. Pigments, unlike dyes, are insoluble which means that they do not penetrate into fibers or yarns and sit on the surface of the garments which allows an immediate “worn” appearance more economically than dyeing followed by abrasion. The cycle time is low and the energy and water requirements are lower than dyeing. They can present a problem with machine contamination, the shades are generally dull and the crockfastness and wash-fastness are low.

    Sulfur dyes

    • Sulphur dyes are still heavily favored by leading jeans producers, especially when the blue-black tone of reactive blacks can be reproduced.

    The primary advantages of using sulfur dyes as opposed to reactives in dyeing jeans are:

    • Sulfur dyes produce dark shades at much lower costs than reactive dyes.
    • The dyeing cycle time and water consumption can be 50% less than with reactive dyes.
    • Energy costs, especially with steam and hot water are greater with reactive dyes.
    • Reactive dyes are high-chroma dyes, like acid dyes, producing intense, bright shades that convey an unnatural appearance. Because sulfur dyes form clusters of molecules like Indigo, the low-chroma appearance reproduces so-called “earth-tones” favored in jeans.
    • Repeatability of shade, coverage of immature cotton and the ability to produce novelty effects are additional advantages with sulfur dyes.

    Sulfur dyes, like Indigo are insoluble in water and after washing are much easier to remove from waste streams than reactives or directs. Sulfur dyes can also be recovered and reused or are suitable for application in standing baths.

    Forms of Sulfur Dyes

    Sulfur dyes are available in powder or liquid forms. Sulfur powders have a lower direct cost, but the quality can be variable and analytical tests should be conducted to determine purity, strength and dyeing consistency. Powders can be difficult to solubilize resulting in poor color-fastness to crocking and washing and are difficult to prepare for dyeing. With adequate reduction of the dye, powders can produce adequate results in batch dyeing where circulation is strong as in package or garment dyeing, but should be avoided in continuous dyeing,especially on Indigo dyeing machines. Liquids sulfur dyes can be added to machines with littleor no preparation and yield higher quality dyeings.

    Liquid sulfur dyes which are pre-reduced, generally are available in 2 forms:

    • The low-sulfide pre-reduced dyes, identified commercially as RDT’s, which normally use a reducing sugar(dexrins, corn syrup, sugar, molasses) for reduction. This type of pre-reduced sulfur compared to the sulfide-type reduced dye has the following characteristics: low odor, shorter dyeing cycle, higher salt requirement in batch dyeing, strike (how fast the dye goes on the fabric-too fast a strike results in uneven shade) is controlled by rate of temperature increase, higher costs than the sulfide type, a lower chemical oxygen demand in water treatment and less water use.
    • The sulfide/polysulfide pre-reduced dyes have a sulfur odor, a longer dye cycle in some applications, requires less salt, the strike rate is controlled by how quickly the dye is added and this type can be used at much lower cost. Sodium sulfide should not be utilized as the reducing agent because of low solubility. The more soluble sodium hydrosulfide (NaSH) offers much greater dyeing quality and low costs. There are other hydrosulfide reducers than can dye sulfurs at a pH as low as 9.5 and are suitable for dyeing wool and silk with sulfurs alone or in blends with cotton.

    Temperature considerations are significant. The low-sulfide dyes or any sulfur dye that is reduced with the RDT principle requires a higher dyeing temperature, usually 90 C for all sulfur colors while the soluble sulfides (NaSH) can be applied at temperatures from 30 to 70 C. In addition to much higher energy consumption during dyeing, as temperature increases the strike rate increases which means that the dye will go onto the garments so quickly, that shade variation can occur and other than dark shades such as sulfur blacks, the use of the reducing sugar (RDT) type of reduction should be avoided for light and medium shades with sulfurs and especially not with blends of 2 or more sulfur dyes. Additionally, there is great flexibility with 

    “Tones” in Sulfur Dyes

    The word “tone” refers to an effect that causes different color appearances in which the black possesses a reddish, bluish or greenish effect. In terms of strict color science, “black is not a color, but a “condition of equal reflectance across visible wavelengths of light at low levels”. Black, like neutral greys and white do not possess hues such as red, green, yellow, blue etc. The reddish tone in sulfur blacks is common, but not as desirable as a blue-black commonly produced in garment dyeing with reactive black. Producing a blue-black with powder dyes is difficult and for the bluish tone, there are specific liquid dyes that are available for this purpose. Most liquid sulfur blacks will produce a greenish tone at adequate levels of reduction. In addition to the various tones that are produced with different sulfur dye products, there also exists a contrast between “brighter” and “duller” appearances which in color science correspond to “high chromatic” and “low chromatic. The better the dye dispersion the higher the chroma or brightness. High chroma dyeings are more colorfast, but have a lighter appearance.

    imageThis is a guest post by Harry Mercer. Mr. Mercer has 30 years experience in the denim business including 3 prominent U.S. denim companies. He is an expert colorist for measurement and color matching as well as textile testing.

  • Sustainable Development Through Denim Chemicals From Garmon and Bozzetto

    “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs”

    says Brundtland Politician and sustainable development leader.

    image

    This concept has been imbibed by Garmon and Bozetto – who are a chemical manufacturing company from Italy and firmly believe in innovation with sustainability.   According to them , world still lacks the know-how and technologies to be 100% sustainable; but they are doing their bit and  moving forward by :

    • Reducing the water consumption required for treating garments
    • Reducing the temperatures required, required energy and Co2 emissions.
    • By using chemicals with lower environmental impact.

    They mention that they can reduce water consumption by combining a range of production processes:

    • WaterSTONE WASH + BIO-BLEACH Savesat least24 lt. per garment(2rinsesr.b. 1/10 + bleachr.b. 1/10)
    • NEUTRALIZATION + DESIZINGSavesat least16 lt. per garment(neutralizationr.b. 1/10 + rinser.b. 1/10)
    • NEUTRALIZATION + STONE WASHSavesat least16 lt. per garment(neutralizationr.b. 1/10 + rinser.b. 1/10)
    • SOFTENER+ BIO-POLISHINGSavesat least16 lt. per garment(bio-polishingr.b. 1/10 + rinser.b. 1/10)
    • SOFTENERSPRAYSavesat least4lt. ofwater per garment
    • DIRECT DYEING + BIO-POLISHINGSavesat least16 lt. per garment(bio-polishingr.b. 1/10 + rinser.b. 1/10)
    • REACTIVE DYEING + BIO-POLISHINGSavesat least16 lt. per garment(bio-polishingr.b. 1/10 + rinser.b. 1/10)
    • PIGMENTS DYEING + BIO-POLISHINGSavesat least16 lt. per garment(bio-polishingr.b. 1/10 + rinser.b. 1/10)

    Garmon & Bozzetto’s ECO-SUSTAINABLE process allows all production phases to be carried out “cold” or at the lowest possible temperature.

    • COLD DESIZIN GA saving of 35°C equal to 3.5 m3of methane and 6.65 Kg C02
    • STONE WASH AT 40°CA saving of 15°C equal to 1.5 m3of methane and 2.85 Kg C02
    • BIO-POLISHING AT 40°CA saving of 10°C equal to 1 m3of methane and 1.9 Kg C02
    • COLD BIO-BLEACH A saving of 40°C equal to 4 m3of methane and 7.6 Kg C02

    Some more details on their eco sustainable denim products can be had from this presentation below

    ABOUT THE COMPANY
    Garmon & Bozzetto Italian Fashion Chemicals is a JV, result of a successful cooperation between two Italian companies leaders in the textile market worldwide:

    • Garmon, present on the market for over 30 years, pioneers, since the 80’s, in the research and development of formulas and chemicals for garment wet processing.
    • Bozzetto Group, a chemical company, with a tradition behind it: almost one hundred years of ongoing improvements, with a constant evolution in technology, products and territorial expansion with a wide range of chemical auxiliaries, which cover the complete textile chain, from spinning to finishing.

    The strong reliable and innovative know-how of GARMON & BOZZETTO is the result of a combination of experiences and of the presence, in the Denim market, since the beginning of the’80s: the boom of the use of this fabric has, in fact, lead the company to sign relationships with the major national and international manufacturers.

    GARMON & BOZZETTO owes its success to a highly motivated team inspired by a genuine passion for casual fashion: it is a group of young, dynamic and highly specialized technicians continuously engaged in finding innovative, surprising solutions and in constant contact with designers of the most important brand.

    To add value to their customers, they also organise training classes based on both theory lectures on the know-how of the chemical formulas
    ITALIAN STYLE: A COSTANT INNOVATION.
    THE ITALIAN JOB  is  a structure entirely dedicated to the activities of R&D.

    THE ITALIAN JOB’s team is working daily on new applications and new formulas offering to the customers the possibility to create samples and prototypes with innovative treatments and by using performing chemicals.
    Behind the concept of “Finishing” there is a process that embraces all the know-how and creativity of the Made in Italy, in fact, “Italian style finishing” is the benchmark for fashion worldwide and represents the added value for those customers.

  • Advances in the Ammonia Mercerization And Finishing in Denim

    Mercerization Denim

    The use of ammonia in mercerization has been known since the 1930’s and was developed commercially for fabric processing around 1970 in what was originally known as the Tedesco process, which was subsequently acquired by the Sanforized company and made well-known as the Sanfor-Set®process. The fashion appeal of so-called “flat-finish” denim resulting from Japanese ammonia-finished denim that many companies substituted caustic-mercerized fabrics, often presenting them as ammonia finished.

    By combining ammonia mercerization and Sanforizing in a single step shrinkage control is greatly improved in denim. In contrast to caustic mercerization, the fabric is softer, semi-permanent press properties result and in the case of twill fabrics, there is less seam-puckering in garments, less leg- twist and edge-fraying.Unlike caustic mercerization, the fabric is not degraded, avoiding a harsh hand even after multiple washings. The resistance to abrasion, tear and tensile is significantly improved.

    The difference in effect as opposed to caustic mercerization is because with ammonia, there is less fiber-swelling, therefore the fibers are more pliable, which allows them to bend and recover more easily when tension or stress is applied. Additionally, unlike standard wet-finishing of denim, the ammonia penetrates completely into yarns and fibers, resulting in complete wetting, which is necessary for plasticizing the cotton for consistent shrinkage and elongation. In garments that are fabricated from ammonia treated-fabrics, the garment life is longer after long periods of wear and repeated washings, improving sustainability.

    The much smaller molecular size of ammonia allows it to penetrate completely into every fiber of the fabric, unlike caustic which causes such rapid fiber- swelling that the caustic is blocked at the surface of yarns, preventing further penetration. The surface tension of ammonia at 26 dynes/cm is a third that of caustic (NaOH). The lower surface tension overcomes the enormous resistance of air trapped in the fabric which is a characteristic of heavy cotton fabrics. Additionally, at normal mercerization concentrations of caustic (23%/30 Baume), sodium hydroxide forms a hepta-hydrate with water (NaOH·7H₂O), which results in a slow-moving, bulky group.

    The permanent-press effects are achieved without the use of cross-linking resins, however, the commonly-used resins are soluble in ammonia and a combination resin finish and mercerizing, plus Sanforizing can be achieved if a soluble catalyst is employed. Additionally, ammonia acts as a formaldehyde-scavenger and resin-treated fabrics that are ammonia treated will produce no free-formaldehyde.

    As a rule, fabric shrinkage depends on the time of exposure to the ammonia, with 80% of the shrinkage occurring in the initial 6 seconds. Very close control of final shrinkage is achieved by fabric tension in the ammonia application in combination with compressive shrinkage.

    By 1974, the primary application of ammonia mercerization was for treatment of heavy-weight cotton fabrics such as denim and corduroy, which are difficult to properly mercerize with traditional caustic treatments. The ammonia process was intended as a replacement for conventional mercerizing for both fabrics and in mercerizing sewing threads (Petrograd process).

    The original process consisted of passing the fabric though a bath of liquid ammonia with 100% pickup for approximately 10 seconds. The ammonia was removed with dry heat applied by passing over blanketed, steam heated dry cans which removed about 90% of the ammonia which was then recovered by a recovery plant consisting of large, pressurized towers and made available for recycling. The rest of the ammonia, which chemically bonded to the cellulose, was removed by light steaming.

    The original ammonia recovery methods required a large capital investment which limited acceptance in the textile industry, however, a more recent design has adopted patented seals that totally isolates the dry and steam process sections in order to avoid ammonia from coming into contact with water and air subsequently eliminating the need for an expensive distillation and recovery operation. Furthermore the seals also isolate the machine from the outside environment so that there are absolutely no ammonia odors in the room where the equipment is operating.

    This unit also does not employ a felt calender, which can also transfer contamination from denim subsequently this process also has the advantage of allowing denim to be processed on the same machine without contamination of non-denim fabrics as well as reducing the problem of backstaining with denim that occurs in caustic mercerization, since no water is required for washing..All the limited residues of non-recyclable ammonia are completely neutralized and can be safely sent to the water treatment plant, so together with the significant reduction in water usage, this newer ammonia process can actually be considered environmentally friendlier than conventional caustic mercerization.

    Ammonia- mercerization provides a higher dry-crease recovery and higher shrinkage consistency than caustic mercerization, especially with the dry-steam method of recovery. However, caustic mercerization still has an advantage with regard to luster and improved depth of color in dyeing, although the uniformity of dyeing after mercerization is significantly improved with ammonia. Ammonia treatment results in a more rounded cotton fiber, which scatters light more, in turn resulting in a luster that is less bright.An additional advantage of ammonia mercerization is the absence of alkaline oxy-cellulose that results with caustic treatments, which is evidenced by strength-losses and dyeing variation. The lower pH of ammonia allows safe treatment of more sensitive fibers like linen (flax)or silk.

    With caustic treatments of fabrics like denim, the elimination of washing required in caustic mercerization avoids the problems with removing caustic. Mercerizers are not normally equipped with drum washers for removal of caustic from heavy cotton fabrics and contamination remains on the fabric at the time of drying which results in damage to cotton. The use of acetic acid to neutralize creates a problem with the formation of sodium acetate , which produces a very harsh feel.The ammonia process on denims also produces a much flatter, richer appearance and improves the performance on stretch denim improving fit.

    Tension control is important in both ammonia and caustic mercerization for improved fabric tenacity and elongation. Moisture regain is improved in both if tension is applied prior to fiber swelling.On the newer system, tension is automatically controlled and adjusted through load cells.

    The ammonia finishing process offers denim companies a simplified process for producing higher quality fabrics with greater appeal to the fashion retailers and also to non-denim cotton fabric providers. There is also the opportunity for commission finishers to purchase unfinished denim and convert it into higher value-added products.

    imageThis is a guest post by Harry Mercer. Mr. Mercer has 30 years experience in the denim business including 3 prominent U.S. denim companies. He is an expert colorist for measurement and color matching as well as textile testing.

  • Indigo Dyeing Methods – Engineering Color, Wash Fastness And Fashion Effects

    This is a guest post by Harry Mercer. This is a very technical description – read on if you are technically oriented..

    Here are given some important dyeing processes related to indigo dyeing – specially on Rope Dyeing .

    Pre Treatment

    Pre-treatment is conducted in the 1st tank. The most common pre-treatments are :

    1.  Sulfur bottoming

    2.  Scouring with sodium hydroxide

    3.  Causticizing or Mercerizing

    Pre- Treatment : Sulphur Bottoming

    •The purpose of sulfur bottoming was to:

    • Originally to produce a dark shade on denim using less Indigo for lower costs
    • In the U.S. sulfur bottoms were dyed using a combination of blue and black dyes
    • In denim operations outside the U.S. the bottom is normally dyed with sulfur black

    Pre – Treatment : Cotton Scouring

    Cotton fibers contain impurities like waxes, pectins and minerals that will interfere with Indigo dyeing and result in streaks.-Sodium hydroxide at low concentrations (<5%) are applied at high temperatures (>85 C) in order to remove impurities and melt natural cotton waxes.

    Pre – Treatment : Causticizing

    • Causticizing generally refers to using sodium hydroxide at below Mercerizing concentrations (<18%).
    • Cold causticizing of cotton yarn results infaster Indigo dye fading from laundryabrasion, darker Indigo color with the same % of Indigo and unique washdowns.
    • Hot causticizing improves colorfastness

    Pre – Treatment : Mercerizing

    Mercerizing is the use of strong sodium hydroxide (18-30%) to swell surface fibers.

    Caution:

    • When using strong sodium hydroxide it is important to remove all of it.
    • If sodium hydroxide is on the yarn as it enters the Indigo tanks, the yarn color will change.
    • Concentrations of sodium hydroxide more than 18% are not a solution, but a gel and are difficult to remove.
    • Mercerized yarns are more ring-dyed and dye more darkly than non-Mercerized.
    • Mercerizing is normally conducted at low temperatures, but hot Mercerizing can be employed for a more abraded appearance after garment laundering.

    Indigo Dyeing

    • Indigo dyeing is unique and because of the complex chemical reactions should be correctly viewed a a form of chemical engineering.
    • Only Indigo dyeing requires multiple dye applications for a dark shade.
    • Color consistency of Indigo in recent decades has been unsatisfactory as a result of machine designs that do not apply basic principles of fluid mechanics properly and unstable dye mixes.
    • Commonly, a single dye lot will have between 8 and 15 visually different shades from beginning to end and also have shade differences from one side to the other.

    Indigo Dyeing Methods

    Spectrum_single_thread

    • Indigo dyeing follows the same basic steps regardless of machine design.
    • Scour or dye bottoming in a heated tank,
    • washing tanks, dyeing(1-20),a heated tank for topping (optional) and wash tanks.
    • In different areas of the world,the same color is produced using 1.8, 2.0 or 4% Indigo depending on dyeing method.

     

    indigo dyeing methods

     

    Dark Indigo(1.8%)

    1. 15% caustic cold
    2.Wash 60°C
    3.Wash 60°C
    4. Wash cold
    Drying cylinders hot
    Steamer cold
    Boxes 5-12 Indigo
    Steamer cold
    13.Wash 50°C
    14. Wash 50°C
    15. Wash 50°C
    16.Wash 50°C /Softener

    Stock Mix 80 g/l Indigo Pure 100 g/l 50% Caustic 70 g/l Hydro powder.

    Chemical Feed 120 g/l 50% caustic 60g/l Hydro powder Feed 1.4 liters per minute

    Dark Indigo Color

    • This was an example of a typical method used in the U.S. for a very dark shade.
    • In order to produce the same depth of color as 1.2% in the U.S., in Latin America 2.0% is used and in Asia from 2.4 to 2.8%.
    • The U.S. method results in more surface (ring dyeing), which loses color faster.

    Darkest Indigo Shades

    • Very dark shades of Indigo are in demand currently around the world.
    • Many companies use 4% or more Indigo on weight of yarn, which is expensive.
    • 2% Indigo will produce the same depth if low levels of caustic are used(0-0.4%)
    • For dark Indigo that does not lose color 2% applied normally, with an Indigo bottom.

    Light Indigo Shades

    • Dyeing Indigo in light shades results in a sky-blue impossible with any other dye.
    • This is useful for shirting fabrics that are  not strong enough for stonewashing,  bleaching or cellulase treaments.
    • Special procedures are necessary in order to avoid colorfastness problems.

    indigo dye baths

     

    Light Indigo 0.4%

    1. 4% caustic 90°C
    2.Wash 60°C
    3.Wash 60°C
    4. Wash 60°C
    Bypass drying cylinders
    Bypass steamer
    Close off boxes 5-8
    Boxes 9-12 Indigo
    13. Wash 50°C
    14. Wash 50°C
    15. Wash 50°C
    16.Wash 50°C/softener

    Control Of Sulphur Bottoming

    • The typical methods used for dyeing sulfur bottoms result in denim shade differences.
    • When applied as light colors, sulfur dyes should be dyed at temperatures <60 C,
    • If dextrin reducing agents are used, which require 85 C, there will be variation.
    • Sulfur bottoms are an exception to the normal pH for sulfurs(11), requiring 12.

    indigo machine

    Sulfur Bottom

    1. Pad sulfur(cold)
    Steamer hot
    2.Wash cold
    3.Wash 50°C
    4.Wash 50°C
    Boxes 5-10 Indigo
    11. Indigo or wash 50°C
    12. Indigo or wash 50°C
    Bypass steamer
    13. Wash 50°C
    14. Wash 50°C
    15. Wash 50°C
    16.Wash 50°C or softener

    Sulphur Topping

    • In topping the sulfur dye is applied after the Indigo dyeing.
    • Sulfur topping permits much darker color than a sulfur bottom, but is duller.
    • Sulfur topping colors include black, blue-black, yellow brown and green.
    • Sulfur toppings are used to produce slub appearances in normal yarn.

    indigo dyeing machine

    Sulfur Top

    1. Pre-wet 2% caustic 90°C
    2.Wash 60°C
    3.Wash 60°C
    4. Wash cold
    By pass drying cylinders
    Bypass steamer
    Boxes 5-10 Indigo
    11. Wash 60°C
    12. Pad sulfur topping
    Steamer hot
    13. Wash cold
    14. Wash 50°C
    15. Wash 50°C
    16.Wash 50°C/Softener

    Reactive Dyes in Indigo Dyeing

    • Reactive dyes can be applied on specially-Designed Indigo machines.
    • Small 150 liter boxes are inserted inside the larger dye tanks for Indigo and sulfur.
    • Steamers, drying units near the front of the machine and high-quality dye padders are required for quality dyeing.

    image 

     

    Pad-Dry Chempad- Steam Reactives

    1. Pre-scour wetter plus chelate 90°C
    2.Wash 50°C
    3. Pad monochlortriazine dye cold, neutral pH
    Drying cylinders hot
    Pad caustic in salt brine
    Steamer hot
    Bypass boxes 5-10
    11. Soap 90°C
    12. Soap 90°C
    Steamer hot
    13. Wash 60°C
    14. Wash 60°C
    15. Wash cold
    16.Wash cold/softener

     

    Pad Steam Reactive Topping

    1. Pre-wet 10% caustic 90°C
    2.Wash 60°C
    3.Wash 60°C
    4. Wash cold
    By pass drying cylinders
    Bypass steamer
    Boxes 5-10 Indigo
    11. Wash 60°C
    12. Pad Dichorotriazinyl cold with bicarbonate
    Steamer hot
    13. Wash cold
    14. Wash 50°C
    15. Wash 50°C
    16. Wash 50°C / softener

    Vat Dyeing

    • Indigo and sulfurs are types of vat dyes.
    • In non-denim cotton dyeing, another class of vats, anthaquinoids are used to produce a full range of colors that are colorfast.
    • Some of these vat dyes can be blended with Indigo or applied using standard procedures on specially designed machines.

     indigo dyeing machine

    Pad-Dry Chempad Vats

    1. Pre-wet 4% caustic 90°C
    2.Wash 60°C
    3. Pad vat dye cold
    Drying cylinders hot
    4. Chempad caustic/hydro cold
    Steamer hot
    Bypass boxes 5-10
    11. Wash 60°C
    12. Oxidize
    13. Soap with anti-oxidant
    Steamer hot
    14. Wash 50°C
    15. Wash 50°C
    16. Wash 50°C / softener

     

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    Pad-Dry Chempad Steam Vat Bottom

    1. Pre-wet 4% caustic 90°C
    2. Wash 60°
    3. Pad vat dye cold
    Drying cylinders hot
    4. Chem-pad caustic/hydro cold
    Steamer hot
    Boxes 5-10 Indigo
    11. Wash 60°C
    12. Soap 90°C
    Steamer hot
    13. Wash cold
    14. Wash 50°C
    15. Wash 50°C
    16. Wash 50°C

     2-1_indigo_washer

    Control Of Indigo Dyeing

    The Indigo dyeing process begins with a concentrated mixture of Indigo, sodium hydroxide and reducing agent.  This concentrated mixture (70-90 g/L Indigo) is delivered by pipes to the Indigo dye tanks where the dye concentration is reduced to 1-4 g/L for dyeing the cotton.

    Dye Mixing Procedures

    • Many denim companies find it difficult to control original and washed Indigo shades.
    • The primary source of color differences is the instability and inconsistency of Indigo mixtures.
    • As the concentration of reducing agent going to the dye machine changes, the color changes.

    Uniform Indigo Mixtures

    • For consistent Indigo dyeing, the mixture must have consistent concentrations of Indigo, sodium hydroxide and reducer from the top of the mixture to the bottom.
    • The main cause of inconsistent Indigo mixtures relates to concentration levels.
    • Instability of Indigo mixtures results from the decomposition of sodium hydrosulfite.

    Consistency of Concentration

    • There is a limit to the amount of any chemical that can be dissolved in water.
    • When the limit of solubility of any chemical •In water is exceeded, precipitation occurs.
    • Indigo mixes should not have more than 20% solids. At higher levels, chemicals and dye sink to the bottom of the tank.

    Improving Dyeing Consistency

    • When reducing agent sinks to the bottom of the tank, there is a higher concentration  than in the top of the tank. As the dye enters the machine, the higher concentration results in a lighter, greenercolor and as the dye from the top of the tank enters the machine, the color is darker and redder.

    Dye Control In Feeding  Tank

    • Stirring the tank for 2 minutes will improve dye uniformity between top and bottom.
    • To avoid settling of dye and chemicals the total solids should not exceed 20%.
    • The “glass plate” test can be used to test concentrations of hydrosulfite in the top and bottom. If dye requires 50 seconds to oxidize, there is about 50 g/L of reducer.

    Buffers In Indigo Dyeing

    • Alkaline buffers have been used to make very dark shades of Indigo with as little as 1% dye, more ring-dyed, faster fading.
    • Reductive buffers can eliminate color differences in Indigo-dyed denims and can reduce hydrosulfite use by 30-50%.

    Cold Dyeing Methods

    • Sulfur colors can be dyed at low temperatures with specific buffers which produce more colorfast dyeings with no color variation.
    • Cold dyeing methods have been used to blend Indigo and sulfurs, eliminating the need for separate bottoming and topping, while eliminating shade changes in both.

    Special Dyeing Techniques

    • On rope ranges, space dyeing techniques can be simple and produce a wide range of special effects in denim.
    • By dyeing part of the yarns with a sulfur top and leaving the rest un-dyed, many companies produce a slub appearance with regular yarns.
    • Blending ring yarns of different sizes also produces a slub appearance.

    imageThis is a guest post by Harry Mercer. Mr. Mercer has 30 years experience in the denim business including 3 prominent U.S. denim companies. He is an expert colorist for measurement and color matching as well as textile testing.

  • Download Denim Thread Consumption And Thread Cost Garment Calculators

    image

    AneCalc is a tool developed by American & Efird to assist in estimating the thread consumption and cost per thread cost per jeans / garment alongwith the number of cones one needs for a given programme. The tools are the in the form of a an excel spreadsheet and one has to just enter basic information to get the consumption and costs.

    There are basically three AneCalc spreadsheets.

    Lightweight : 2- 4 oz weight fabrics.

    Medium weight : 5-8 oz fabrics.

    Heavy Weight : 9 –15 oz fabrics.

    The weight of the fabric determines the ratio of  needle to bottom thread on the thread consumption table.

    For each sewing operation on the garment , you will need to list the name of the sewing operation, what ISO stitch type is being used , how many rows of stitches are there , the Stitches per inch , and the length of the seam .

    When you download the spreadsheets, you will find different tabs as shown below

    image

    Chose the ‘New Help Guide’ to understand how to use this tool and ISOStitches to understand different kind of stitches. The actual working is done on the ‘Worksheet’.  You can change the name of the threads that you use under column ‘M’ of the worksheet.

    Download the calculators

    If you need help with the calculators, leave a comment under the post .

  • Wish You A Happy New Year 2011

    Wishing all our readers and visitors a Very Happy New Year 2011.. May this year be full of happiness, success and prosperity for you and your family..

     

    happy-new-year2-denim