“PRODUCTION OF DENIM FABRIC BY THE USE OF SLASHER DYEING” DEPARTMENT OF TEXTILE ENGINEERING Project Report On “PRODUCTION OF DENIM FABRIC BY THE USE OF SLASHER DYEING” Introduction Introduction Denim is the oldest, most widely used, most fashionable and most versatile fabric of the world. At present denim is mainly used for producing garments particularly trousers for the young people. The gross production of denim fabric is approximately 3,000 million metres per year. Denims are produced from 4 oz. to 16 oz./ sq. yds in weight. Technically Denim is defined as a 3/1 warp faced twill but also produced from weaves like: Left hand twill, right hand twill, broken twill, cross hatches, cords, dobby's, structures, etc . Denims are made from yarn dyed warp and undyed weft. Traditionally, denim was dyed with various shades of indigo, yarn-dyed, different costs, and over-dyed with various types finishes at fabric as well as garments state. Denims are manufactured different types of after treatments or washes like stone wash, bleach wash, hand wash, acid wash, over dyed, printed denims and even embossed. Denim fabrics are used as jeans trousers both for men and ladies. It is extensively used in the world as casual garments, Shirts, jackets, children wears are also made of denim fabrics. Its versatility, finds applications in furniture upholstery, bed covers, curtains, etc. Denim now-a-days is a very demandable product. To make a denim fabric the required yarn for the definite construction should be dyed then make a weavers beam to go to weaving to make fabric. TYPE OF FABRIC : TYPE OF FABRIC : Normal Fabric Ring Fabric Half Cross Fabric Cross Latch Fabric FABRIC IDENTIFICATION : Normal Fabric = 6 OE * 6 OE / 66 * 35 Ring Fabric = 6, 9, 12 * 7 OE / 66 * 35 Half Cross Fabric = 6 slub * 7 OE / 66 * 35 Cross Latch Fabric = 10 slub * 10 slub / 66 * 35 TYPE: 'Some typical denim fabric construction: Description Wt oz/yd 2 Construction: Finished Fabric Desig n 100%Cotton indigo Half Cross Denim 6 89X55/20RsX16R+16R s 2/1 RHT 1 00%Cotton indigo Ring OE 8 77X49/13RX12R 2/1 RHT 100%Cotton indigo Vertical Slub 7.25 68X49/1 ORsX20K i2/IRH T 100%Cotton light Indigo Slub Lucky 6.50 79X49/1 6RX14Rs 2/1 RHT 98.5%cotton 1 .5%lycra park indigo stretch slub 11.50 65X46/7.5RsX8+70D 3/1 RHT 100% Cotton indigo normal 12 10 OE+10 OE*12 OE/69*44 2/1 RHT 100% Cotton indigo 12.10 9 Rs+ 9 R * 7Rs + 7R/ 72 *48 3/1 RHT 100% Cotton indigo 11.65 8 Rs + 9R* 8Rs (MC) / 68 *50 3/1 RHT 100% Cotton indigo 9.8 9 OES+ 9 OE* 10 OE / 75 * 43 2/1 RHT Most of the denims are produced with 100% cotton and cotton-based blends with Lycra®, Polyester, Tencel®, Bamboo, Jute, Nylon, and Linen etc. An ideal cotton mix for denim should have the following quality parameters. 2.5% span length > 25mm Strength (g/tex) >18 Micronaire > 4.5 to 5.0 Maturity Coefficient >0.75 Uniformity Ratio> 49% Trash> 4.9% In Bangladeshi mills, in most cases substantial quantity of waste yarns are used. This is mainly done to reduce the cost of production. A well established mix for denim yarns are as follows; i. 80% waste, which consists of (i) Dropping-1, (ii) Dropping-2, (iii) Flat strip, (iv) Comber noil. ii. 20% Fresh Cotton FIBRE YARN (i) Rotor yams are the best and most widely used yarns in Denim production. Because of their very high speed rotor yams are much cheaper than ring spun yams. Off course rotor can only produce yarns of up to 30Ne. Though cheap rotor yarns are associated with greater imperfections than corresponding ring yarns therefore knit goods are produced from ring yarns. (ii) Count range from 6 to 16 Ne but most widely used range is 7 to 12 Ne. For slub yarn the range is 9 to 20 Ne. (iii) Quality- Counf CV-<1.2, Single yarn strength> 12.8 gm/tex, Elongation> 6.0,U% <9.5. (iv)As huge amount of slub yarns are used today the idea of too much strict U% is not considered. The diameter of slub varies froml.SD to 2.2D (Where D is the normal dia of yarn). The periodicity of slub also varies widely. Test results show mat the distances between two adjacent slubs varies within certain range. Some of the usual range distances between two adjacent slubs are from 6cm to 10cm, 7 cm to 20 cm, 30cm to 60cm. Some more information on yarns are given in weaving section later [...]... Normally the process of dyeing dictates the technology of denim manufacturing The following twoDyeing methods are most popular processes for manufacture of denim SLASHER DYEING: Slasher dyeing dyes the yarns in the warp beam form It is a continuous process which combines dyeing & sizing in a single operation Dyeing is done by continuously passing warp yarns through several (at least 5) troughs of indigo... liquor The dyed yarns are then sized & wound onto a warp beam to be ready for use in the weaving process Slasher dyeing is usually of inferior quality as compared to rope dyeing shade evenness or side-to-side shade variations With the slasher dyeing, the penetration of dyestuff is poorer, and it is easily reveals an uneven pick-up along its width with the distortion of the pad-roll Fig: Diagram of Slasher. .. that reduces the surface tension between the material & liquid Detergency effect helps to clean the material 03 Sequestering agent: It reacts with metallic ions & thus makes the metallic compounds to become a part of complex anion DYEING: Dyeing is consists of 2 dyes The indigo blue & Sulphur black is used in the dyeing process of denim Sometimes brown color is used instead of indigo blue in the factory... Mutton tallow: It is prepared from the sheep & is chemically composed of the glycerides of stearic, oleic & palmitic acids After warping, dyeing and sizing a weaver's beam is produced The weaver's beam, after drawing and denting is then mounted in the loom to produce the fabric Weaving of denim fabric is not much different from weaving all other fabric except the idea about the warp and weft way shrinkage... properly in the dye solution Specification: Manufacturer = BASF Country = India Persoftal BD (Paste): It is a softener, used to soften the fabric in the finishing process Antioxidant: It is used to protect oxidation of dye molecule in dye bath It is used as reducing agent while Sulphur black is used It is also known as monohydrate glucose Acetic Acid: It is used to reduce the percentage of pH in dye... composition depends on the following factors: •Types of fibers •Types of yarn •Yarn quality •Quality particulars of fabric to be woven •M/c condition & ambient condition of the loom shade •Cost of various ingredients The Starch & Softener are used in the sizing bath are given below: Starch: Emsland E-55 (Modified starch) Emsland E-14 Softener: Mutton Tallow Fin Fix Starch: Trefin Wax These are products... even fabric surface for the next process 03 To increase the absorbency of the fabric, i.e to make the fabric hydrophilic, so that it can absorb dye molecule, water & other processing easily Scouring Recipe: NaoH= 36-145 gpl or g/l Wetting agent (Lionil EH) = 0.5g/l Temperature=85ºc Water = 1400 liter Squeezing roller pressure = 4-5 bar FUNCTION OF THE CHEMICALS USED IN SCOURING: 1 Alkali: It converts the. .. waxes together with other impurities During manufacturing oil & adventitious dirt are collected And these are affected the absorbency of the cloths & leads to uneven dyeing Oil, fats & waxes are all insoluble in water; they dissolve in organic solvents such as Chloroform, Ether and Petrol etc Scouring is the process to remove all these impurities to make a more absorbent, hydrophilic & clean fabric OBJECT:... agent : 0.5 g/l Dyeing Process: Dyeing process that is maintained as follows: Pure Indigo- Continuous Indigo Dyeing Bottoming- Sulphur(Bottom) & Indigo(Topping) Topping- Indigo(Bottoming) & Sulphur (Topping) Black Denim- Continuous Sulphur Black Dyeing Color Denim LIST OF SOME CHEMICALS ARE USED & AND THEIR FUNCTION: Pimazol ws: Use as pre-wetting agent to reduce the surface tension of the liquor and... sizing department; Warping Ring yarn Rotor yarn Dyeing Ring yam Rotor yarn End break per million metres l . PRODUCTION OF DENIM FABRIC BY THE USE OF SLASHER DYEING DEPARTMENT OF TEXTILE ENGINEERING Project Report On PRODUCTION OF DENIM FABRIC BY THE USE OF SLASHER DYEING Introduction Introduction . Normally the process of dyeing dictates the technology of denim manufacturing. The following twoDyeing methods are most popular processes for manufacture of denim SLASHER DYEING: Slasher dyeing. make fabric. TYPE OF FABRIC : TYPE OF FABRIC : Normal Fabric Ring Fabric Half Cross Fabric Cross Latch Fabric FABRIC IDENTIFICATION : Normal Fabric = 6 OE * 6 OE / 66 * 35 Ring Fabric = 6, 9, 12