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PROJECT REPORT ON Application of Disperse & Reactive Dyes In a P/C Blended Fabric of 65/35 In Using Two Bath System BASIS OF FAKIR APPARELS LTD. BSCIC SHILPA NAGARY, FATULLAH, NARAYANGANJ
ACKNOWLEDGEMENT Praise be to Allah the creator and sustainer who has given us strength and opportunity to complete our two months long industrial attachment at “Fakir Apparels Ltd.” Pabna Textile Engineering College has given me the opportunity to perform the industrial project report with “Fakir Apparels Ltd.”. I am grateful Mannan, the principal of the college for giving me the opportunity to accomplish the attachment. to Md. Abdul Special thanks go to my supervising teacher Shib Shankar Chakraborty Sir, without whose help it would not have possible to complete the training successfully. May I also take the opportunity to express my sincerest gratitude to “Fakir Apparels Ltd.” management, and administration & personnel for their kind co-operation. My deepest appreciation goes to ED-Sir and to DGM –Sir, who provided us all the necessary information we needed. Above all, I would like to acknowledge my deep debt to all teachers of our college and especially of “WET PROCESSING TECHONOLOGY Department ”for their kind inspiration and help, which remain as the backdrop of all my efforts. Finally, I would like to acknowledge that I remain responsible for the inadequacies and errors, which doubtless remain.
Application of Disperse & Reactive Dyes In a P/C Blended Fabric of 65/35 In Using Two Bath System.
Abstract The dyeing of the polyester and cotton blend fabric (P/C fabric or PCF) has becomes a challenge to the modern textile industries due to its variation in color value, shed depth, tensile strength and surface residual weight loss. All of this drawback can be control by the proper selection of the dye- fiber combination which ultimately governs the XRD, SEM, FTIR analysis of the dyed blend fabric. The water fastness or wash fastness and light fastness can be also improved by the proper analysis of the thermodynamic equilibrium of dye fiber bond and its stoichiometry. The present work deals with the ways of testing the compatibility of disperse & reactive dyes with P/C blended fabrics dyeing in different textile industries in Bangladesh. This report includes three laboratory trials that were carried out for three different reactive dyes to check the compatibility for use in a dye recipe on cotton knitted goods. In this study, Spectrophotometric analysis was conducted and the fixation of each dye was determined by using computer colour matching system. The results found from different industries were analysed and discussed. This testing can be used as a tool for selecting good quality dyes as well as to reduce dyeing cost and hazard. Finally few recommendations are highlighted to overcome the problem of selecting better quality dyes for cotton goods in textile industries in Bangladesh. Fiber reactive dyes for cotton were shown to vary widely in their substantivity for the fiber. Substantivity also depended on dye bath temperature and salt concentration, as expected. The relative substantivities of the hydrolyzed forms of the reactive dyes were assessed in the laboratory by means of a sample, quick and inexpensive paper chromatography test. Correlation of the substantivity of the dye with the amount removed from the cotton under various washing conditions indicated that it should be possible to select higher or lower washing temperatures based on the substantivity of the dye to be removed. In addition, the paper chromatography test was useful for quick selection of dyes of about the same substantivity. Mixtures of such dyes dyed cotton with little change in hue during the dyeing process; dyes of different substantivity gave pronounced color changes.
INTRODUCTION If the theoretical knowledge is a glass of water, then the practical knowledge would be drinking of the water. So, for any technical education the practical experience is the most important along with the theoretical knowledge.With the evaluation of the wet processing industries the use of the reactive & disperse dyes in the most of the industries increases day by day. As a result to complete the project it is has become a part to discus about the evaluation or growth of the wet processing industries in Bangladesh. Now the number of the wet processing industries and finishing industries in Bangladesh is 206 which are totally export oriented according to the survey of the BTMA which has been provided into their web address. The application & fixing of a dye to a substrate, normally with the intention of obtaining an even distribution throughout the substrate. Dyeing is the Wet Processing Technology by which physical and chemical changes happen in textile material. Reactive dye stuffs directly combinds with cellulose by chemical bonding i.e. covalent bonds are produced. They have excellent wash fastness. Mainly used on cotton dyeing. Can also be applied on wool, silk and nylon dyeing. Dyeing is carried out in an alkaline bath. By achieving Practical knowledge it is possible to apply the theoretical knowledge in the technical field. For any technical education, practical experience is almost equally necessary in association with the theoretical knowledge. The Industrial attachment is most effective process of achieving the practical experience. It provides us sufficient practical knowledge about production, management, productivity, evaluation, work study, efficiency, Industrial management, production planning & control, Production cost analysis, inventory control, purchasing, utilities and Maintenance of machinery and their operation technique etc. Industrial project report is an essential part of four years B.Sc in Textile Engineering course of Pabna Textile Engineering College under the University of Rajshahi. We had the opportunity to perform the industrial attachment at “FAKIR APPARELS LTD.”. During two month long attachment, I am studied the man, machine, material aspects of the knitting section, Dyeing section, quality control section, planning section, grey fabric inspection, finished fabric inspection, finishing section and merchandising section of the factory, also studied about the reactive dyes . According to my studies there we have prepared the following report and would like to present.
Dyeing: Dyeing is the process by which a textile material is to be changed physically or chemically, so that it looks mono uniform colored. Or we can say that , Dyeing is the process of imparting fiber,yarn , cloth or garment form by treatment with a dye. colors to a textile material in loose Blending: Blending is the combining of different fibres together intimately to achieve a desired product characteristic. Blends can influence colouring, strength, softness, absorbency, ease of washing, resistance to wrinkling, ease of spinning, cost, etc.
Advantages of Blending: When two different types of fibres are blended, the properties of these two different fibres are synergised. For instance, in the blend of cotton and polyester, cotton provides the absorbency and polyester provides the strength. Blending is done to produce a fabric, which is economical by combining the aesthetic comfort properties of the natural fibres with the easy care and strength properties of synthetic fibers. Blending also helps to provide the fabric’s light weight with all desirable characteristics.Improving spinning, weaving and finishing efficiency and the uniformity of product. Methods of Blending: Blending can be done at the opening stage, drawing etc. In the initial opening stage of the blow room operation, the fibres are spread one on top of the other and fed into the blending feeder. The blending can also be done in the carding stage. Similarly the blending can be done at drawing or roving stage. A filament yarn blended contains yarns of different deniers (denier is the yarn numbering system used for filament yarns) blended tog.
Polyester Polyester is a term often defined as “long-chain polymers chemically composed of at least 85% by weight of an ester and a dihydric alcohol and a terephthalic acid”. In other words, it means the linking of several esters within the fibers. Reaction of alcohol with carboxylic acid results in the formation of esters. Polyester is a manmade polymer material. It is made from coal, air, water and petroleum products. Polyester is a strong fiber that keeps its shape and therefore resists wrinkling. The fiber does not withstand medium to high temperatures and melts and burns at the same time, therefore ironing polyester must be done at a cool temperature, if at all. Threads of polyester last for a long time and wear well, so are used for many garments and sewing projects. Polyester does not shrink like its natural counterpart and holds dye extremely well, a good thing for textile artists, but bad for stain-removal from polyester items. Polyester was extremely popular in the 1950s but since then is used more as a blend than the main fiber used for garments or fabric. The chemical name for the polyester used in fiber production is polyethylene terephthalate or PET. This compound is also used to make plastic soft drink bottles, which can be melted down after use, allowing the PET fibers to be reused. Companies currently producing polyester fiber include Color-Fi, Dak Fibers, Fiber Science Inc and Palmetto Synthetics. Cotton: Cotton is an all-natural fiber made from the pod of a cotton plant. It is the principal fiber used in making the world's clothing. Cotton is known for being light, cool, comfortable and absorbent. Many people describe cotton as a fabric that "breathes." It is also easy to dye and to clean, though dyes do not hold as fast to natural fibers as to the synthetic fibers of polyester. Cotton can withstand high temperatures, but does wrinkle easily and shrinks with washing.
Blend Benefits A polyester cotton blend can be versatile, as it most likely retains the coolness and lightness of the cotton fiber, but also adds the strength, durability and wrinkle- resistance of polyester. A polyester cotton blend should only shrink slightly in comparison to a garment or fabric that is 100 percent cotton. This blend is often preferred by at-home sewers and quilters as it is extremely easy to sew. Blend Cons Adding polyester to cotton can cause unattractive pilling of the fabric and make the fabric not withstand high temperatures as well. Many people prefer pure cotton to a polyester blend cotton in clothing that they need to breathe, as the blend does not breathe or stay as cool as pure cotton. Uses Polyester cotton blend is mostly used in the garment industry to make clothing that people want to be able to wash and wear without having to iron and that will be tougher than a 100 percent cotton blend and withstand more washing. Many home sewers prefer polyester cotton blends as it is more forgiving and easy to sew than pure cotton, as it wrinkles and shrinks less.
Reason of using Reactive & Disperse Dyes in p/c blended fabric dyeing: Reactive dyes are easily applicable to cellulose fibers & disperse dyes are mostly suitable for polyester that is why for p/c blended fabric both disperse and reactive dyes are used. Other associated reason as follows: REACTIVE: 1. Reactive dyes are soluble in water. 2. They have very good light fastness with rating about 6. 3. The dyes have very stable electron arrangement and can protect the degrading effect of ultra-violet ray. 4. Textile materials dyed with reactive dyes have very good wash fastness with rating about (4-5) due to strong covalent bonds formed between fiber polymer and reactive group of dye. 5. Reactive dyes give brighter shades and have moderate rubbing fastness. 6. Dyeing method of reactive dye is easy. It requires less time and low temperature for dyeing. 7. Reactive dyes are comparatively cheap. 8. Fixation occurs in alkaline condition. 9. Reactive dyes have good perspiration fastness with rating 4-5. 10. It has a wide range of shade DISPERSE: 1.Generally these dyes are insoluble in water, but they are soluble in hot water in some extent. 2.These dyes have no ionic groups.These are used for dyeing hydrophobic fibre like polyester, nylon, cellulose acetate, tri-acetate, acrylic etc. 3.It has no affinity to cellulose fibre. 4. It gives Variety shade of color. 5. Its washing, rubbing, and light fastness are good. 6. It is connected with fibre by hydrogen bond and Venders walls force. 7. Dye particles of these dyes are smaller than the other dyes. 8. These are soluble in organic solvent like benzene, toluene, zyline etc. 9. These are applied in neutral or acetic medium. 10. These are applied at high temperature i.e. 125-140°C. 11. Solubility of this dye bath increase with temperature.
Raw Material Raw materials are those, by using or processing which we get final product. In textile there are different types of raw materials. Such as- Yarn is raw material for fabric, dyes & chemicals are raw materials for dyed fabric. Dyed fabrics are raw material for garments etc. In Fakir Apparels Two Types Of Dyes Are Mainly Used: 1. Reactive dye - Cold Brand (400C) - Medium Brand (600C) - Hot Brand (800C) 2. Disperse dye DISPERSE DYE: Disperse dyes are traditionally non-ionic chemicals with sparing solubility in water which, consequently, are able to retain comparatively better substantivity for hydrophobic fibres, such as polyester, nylon and acetate. For the sake of efficient diffusion into textiles, the particles of disperse dye should be as fine as possible comprising low molecular weight molecules in the range of 400 – 600. It is essential for disperse dyes to be able to withstand various dyeing conditions, pH and temperature, resulting in negligible changes in shade and fastness. Disperse dyes are often substituted azo , anthraquinone or diphenylamine compounds which are non-ionic and contain no water solubilising groups. The dye particles are thus held in dispersion by the surface-active agent and the dyes themselves are called disperse dyes. They are marketed in the form of either an easily dispersible powder or a concentrated aqueous dispersion and are now the main class of dye for certain synthetic fibres . CLASSIFICATION OF DISPERSE DYES: Anthraquinone, monoazo and disazo disperse dyes are the most important classes of disperse dyes in terms of market share, there are a number of other important classes as follows ; - Nitroarylamino disperse dyes - Coumarin disperse dyes - Methine disperse dyes - Naphthostyryl disperse dyes - Quinophthalone disperse dyes - Formazan disperse dyes - Benzodifuranone disperse dyes
Disperse Dyes used in Fakir Apparels Ltd. Company name Imperial chemical company Brand name Taifix Origin UK Dyes name The list is for the time of our industrial attachment. It varies according to the availability of the material & their price. The price has not been supplied to us due to their secrecy act. The annual requirement was not available & is a record of the procurement department. Taifix Red SF 3BT Taifix Yellow SF 3RT Taifix Black SF BSDT Taifix Black SF BT Everzol Black B Everzol Black GR Everzol Red 3BS Everzol Yellow 3RS The list is for the time of our industrial attachment. It varies according to the availability of the material & their price. Huntsman Terasil Terasil G/Yellow W3R Terasil Red W4BS Terasil Red WW-BFS Terasil Blue WRBS Terasil Blue BGE-01 Terasil Yellow 4G Terasil Yellow W4G Terasil Red R Terasil Navy WRS Terasil Black WNS Terasil Orange 5RL Terasil Yellow W5SL Switzerland The list is for the time of our industrial attachment. It varies according to the availability of the material & their price. Nakalon Blue 2 RLS Nakalon Bri. Blue BGF Nakalon Yellow 4GN Naka Naka Japan The list is for the time of our industrial attachment. It varies according to the availability of the material & their price. The price has not been supplied to us due to their secrecy act. The annual requirement was not available & is a record of the procurement department. Remarks:
Reactive Dye: The dye which reacts with the fibers chemically and makes covalent bond with the fibers & become an integral part of it is called reactive dyes. Reactive dyes contain reactive group & the covalent bond is formed between dye molecules & the terminal –OH group of cellulosic fibers respectively. D-SO2-C2H4-OSO3Na + OH-Cell Here, D=Dye part Cell=Cellulose polymer A reactive dye may be represented by: D-B-Y-X Where, D= Chromospheres of dye part B= Bridge (It’s a part of dye molecules) e.g. NH-, -NR group Y= Reactive group bearing part (It can be a heterocyclic ring) X= Reactive atom or group (It can be the halogen group or activated vinyl group) e.g.-CH=CH2 Reactive Dyes used in Fakir Apparels Ltd. D-SO2-C2H4-O-Cell + NaHSO3 Company name Brand name Origin Dyes name Cibacron Yellow FN2R Cibacron Red WB 150% CibacronBlue FNR Cibacron Black WNN HC Cibacron Orange W 3R Cibacron Navy WRS Cibacron White 4BK Cibacron Syno White BRB Ciba Geigy CIBA Switzerland
Reactive Dyes used in Fakir Apparels Ltd. Company name Brand name Origin Dyes name Sumifix Yellow EXF Sumifix Red EXF Sumifix Blue EXF Sumifix Navy Blue BS Sumifix Black B-150% Sumifix Brill Yellow 3GP Sumifix Scarlet 2GF Sumitomo Sumifix Japan Livafix Brill Yellow CA Livafix Fast Red CA Livafix Blue CA Livafix` Red CA Livafix Amber CA Livafix Yellow CA Livafix Scarlet CA Dystar Livafix Germany Remazol Yellow RR Remazol Red RGB Remazol Blue RR Remazol Red RR Remazol Navy RGB Remazol Deep Black GWF Remazol Green 6B Dystar Remazol Germany . . . Dyes origin Origin of Dyes Terasil: Switzerland Drimaren: Germany. Remazol: Germany Levafix: Germany SK: Korea Ciba: Switzerland Sumifix: Japan. Benzactive: Switzerland Terasil & Disperse dyes are mainly used for dyeing polyester. Acid dyes are use to Nylon. Sumifix, Drimaren, Remazol, Levafix, Ciba, Sk all these dyes are use to dyeing the Cellulose or Cellulose based fabric.
Steps of Reactive Dyeing: Dyeing with reactive dye generally done in three steps- Exhaustion of dye in presence of electrolyte or dye absorption. Fixation of dye under the influence of alkali. Washing off the unfixed dye, electrolyte and alkali from material. Steps of Disperse Dyeing: Dispersion of dye in the dye bath with the help of dispersing agent. At high temperature (around 140oC) crystalline structure converted to amorphous form. Then dye molecule enters into the fiber. When cooling happen dye molecules entrapped into the fibers. (Amorphous region becomes Crystalline). Dyeing of polyester and its blends: Dyeing of Hydrophobic fibres: Dyeing of Hydrophobic fibres like polyester with disperse dyes is a completely different dye transfer system. The process involves dye transfer from liquid (water) to a solid organic fibre and it takes as following: 1. Dispersion of the dye in the solid phase into water by breaking up into molecules(dissolution of the dye). 2.Adsorption of the dissolved dye from the solution onto the fibre surface. 3.Diffusion of the dye molecules from the fibre surface into the interior of the fibre. How does it happen: • The first step of dye dissolution in the dyebath depends on the dispersability and solubility of the dye with the help of dispersing agents. • The second step is the adsorption of the dye by the fibre which is turn is affected by solubilition of the dye and fabric affinity. • The rate of diffusion of the dye into the fabric.
Equilibrium in dyeing: • When equilibrium is reached in each of these steps , the dyeing actually takes place. • If the amount of dye present is not sufficient to saturate the fibre only the first two equillibrium will be established. • If the fibre is saturated, the third equilibrium will be attained and dyeing will be completed. • Thus‐ ‐Aqueous solubility of the dye and dye diffusion are the two main factors which govern the dyeing process. Impact of these factors: • The rate of dyeing. • The percentage of exhaustion of the dyebath. • The level dyeing characteristics of the disperse dye. For achieving good fastness: • Addition of small amounts of dispersing agents. • Leads to better exhaustion. • Longer dyeing period ensures better rubbing fastness. • Shorter dyeing times usually cause less level dyeing. Function of the Dispersing agent: • The dispersing agent performs many functions in dyeing. • It assists the process of particle size reduction of the dye. • They increase solubility of the disperse dye. • The choice of dispersing agent is specific for a dye. Dye solubility only helpful to an extend: • Dye solubility only helpful to an extend, although dyeing rate increases with increasing solubility but upto a certain value and with further increase in solubility, the dyeing rate actually decreases. • Each dye has a favorable dispersing agent and is effective with that agent best.
Fibre Swelling: • Fibre swelling take place in hydrophilic fibres such as cotton with water molecules occupying the amorphous regions of the fibre. • This imbibed water help translocation to some extent of the absorbed dye. • However in the case of hydrophobic fibres like polyester the fibre structure is so compact that water is not able to swell fibres as a result minimal amount of water is imbibed in the fibre structure , so slow diffusion of dye takes place. Carriers: • The fibre structure may be opened up by the use of carrier or by thermal energy. • For dyeing polyester fibres at temperatures up to 100 degree without any carrier the diffusion of dye is affected. • Therefore use of carrier is recommended. This facilitates the diffusion of the dye molecules. Selection of carrier: While selecting a carrier for the use in polyester dyeing, the following factors should be considered 1.High carrier efficiency. 2.Availability at low cost. 3.Little or no effect on light fastness on the final dyed product. 4.Absence of unpleasant odour. 5.Non toxicity 6.Ease of removal after dyeing 7.No degradation or discoloration of the fibre Continued 8. High stability under the dyeing conditions. Actual dyeing machines used: In actual practice the polyester components are dyed by the carrier method in 1. Jiggers 2. Winch‐ ‐beck Where the dye used is the ones with high diffusion coefficients, dyes with low diffusion coefficients are less suitable. However uniform heating of the fabric presents difficulties in Jigger due to loss of heat in the open System, even when it is heated to 100 degree the temperature available to the fabric is only 80‐ ‐90 degree. The conditions with Winch‐ ‐beck dyeing are more favorable.
High temperature dyeing: Polyester fibres and their blends may be dyed under high temperature conditions above 125‐ ‐130 degree. Above 100 degrees , the fibre swells to a great extend and hence there is rapid penetration of the dye molecules in the fibre structure. There is decresed resistance to the diffusion of the dye molecules at 130 degrees than at 100 degrees. Even the disperse dye is much more soluble in water at a higher temperature. Factors that matter in polyester dyeing: 1. Dye selection 2. Carrier selection 3. Dyeing temperature and time 4. Use of Glauber’s salt 5. Pre scouring by anionic detergent or liquor ammonia 6. Dyeing 7. After scouring with non ionic detergents and acetic acid. General Information about blend: Blends are any textile materials from the fibres (filaments) through yarn to fabric, which are deliberate combination of chemically or physically different fibrous polymer. Several interrelated factor may contribute to the justification for replacing a homogeneous textile materials by a blend. Economy: The dilution of an expensive fibre by blending with a cheaper substitute. Durability: Physical the incorporation of a more durable component to extend the useful life of a relatively fragile. Physical Properties: A compromise to take advantage of desirable performance characteristics. Color: The development of decorative garments or fabric design incorporating multicolor effect. Appearance: The attainment of attractive appearance using combination of yarns of different luster, crimp etc which differ in appearance even after dye uniformly to the same color.
Dyeing Possibilities with Blend: Union or solid dyeing: Both Fibres: Both fibres are dyed as closely as possible to the same hue, depth and brightness. Reverse or Resist Dyeing: Only one fibre is dyed and the other is kept as white as possible. Cross Dyeing: •Shadow Effect: Same hue and brightness but depth difference. •Contrast Effect: Strong different in hue brightness and depth. Methods of Dyeing P/C blended fabric with Disperse & Reactive Dyes In Two Bath System: There are two methods of P/C blended fabric dyeing as follows: 1. Conservative two bath process. 2. Rapid dyeing one bath process. Sequence of fabric preparation: For woven fabric: Heat Setting(180-205°C for 30-40 sec.) Desizing Scouring & Bleaching Mercerising(optional but not recommended for viscose blend because it will create grains on the fabric surface) For knitted fabric, Only desizing is not required, but all the process is same as woven. Classification of blends: Polyester-cotton:58.4% Polester-viscose: 20.4% Polyester-wool: 7.1% 0ther: Rest of 10% Polyester-cotton blends: For example, 80/20,65/35,70/30, 50/50 are common.
Procedure of Disperse/Reactive dye: Two Bath Process: This is completely separate dyeing & both two dyeing is independent. Polyester Dyeing: Polyester is dyed with disperse dye in Jet dyeing machine in high temperature with the following recipe: Disperse dye= 2% Dispersing agent= 1% Acetic acid= 3 ml/L M: L=1: 10 Time: 100 min Temperature=120-130°C Procedure of polyester dyeing: Disperse dye solution is prepared in hot water(80°C) by stirring & dispersing agent may be used before dye or simultaneously with dye.One part of dispersing agent is added in dye solution & other part is added in m/c with water according to liquor ratio. The dye bath is set at 50-60° C temperature & 1% anionic detergent &rest of dispersing agent is added & then the material is added.Then dye solution is added in the dye bath. Then temperature is raised to 85-90°C within 15 minutes. PH is checked & is adjusted to 5.5-6 by acetic acid. Then temperature is raised to 130°C within 20 mins. Run time of bath is 60-90 min. The temperature is lowered & then bath is drain out. Anionic surfactant+Rest of dispersing agent Dye dispersion 130°C pH adjust by 5.5 by acetic acid 15′ 20′ 60′ Fig: PET DYEING CURVE
Reduction Cleaning: After dyeing, the bath is drained & goods are reduced cleaned to remove unfix surface dyes or cross staining on cotton.The recipe for reduction cleaning is as below: For pale shade: Nonionic detergent=0.5% Soda ash=0.5% Temperature=70-80°C Time= 30 mins For medium to heavy shade: Detergent=1 gm/L Hydrose=2 gm/L NaoH solution(36C)=3-5 ml/L Temperature= 80°C Time= 20-30 mins Cotton Dyeing: After polyester part dyeing,cotton part is dyed with reactive with the following recipe: Dye(cold brand)=3% Common salt= 50-60 gm/L Wetting agent=1 gm/L Soda ash=15 gm/L Temperature=40-50°C Time= 100 min M:L= 1:10 Procedure of cotton dyeing: The dye bath is set at room temperature.Materials,dyes & auxiliaries are added in the dye bath & kept for10 mins in room temperature. The temperature is raised to 50° C with in 10 mins. At 50° C ,the bath is kept 10 mins & then salt dosing is carried out for 10 mins.The run time before salt dosing & duration of salt dosing time is maintained to prohibit the color strike on the fabric.If not maintained uneven shade will yield due to color strike. After salt dosing, the bath is run for 20 mins to reach the dyeing equilibrium between the dye bath & the fabric.If soda is added before reaching equilibrium, then color yield will be poor & dye wastage will be higher.
After salt dosing, the bath is run for 20 mins to reach the dyeing equilibrium between the dye bath & the fabric.If soda is added before reaching equilibrium, then color yield will be poor & dye wastage will be higher. Now soda dosing is carried out for 20 mins. After soda dosing, the material is kept in the dye bath for 20 mins. Then bath is drained out. Reactive dye+ Auxiliaries+ Mtl. 50°C Salt dosing Soda dosing 40°C 10′ 10′ 10′ 10′ 20′ 20′ 20′ Drain Fig: cotton dyeing curve After-treatment: Washing process after reactive dyeing is lengthy but unavoidable to light wet fastness because all hydrolyzed unfixed dye has to be removed.The washing process are as below: Cold wash at 30°C-50°C Hot wash at 60°C-80°C Soap wash with anionic surfactant at 80C-90°C Hot rinse at 80°C Cold rinse.
Technical Deficiency of Disperse & Reactive Dyes: In case of Disperse Dyes… High temperature is needed for dyeing which is Costly to generate. Dispersing agent is required for using disperse dyes as an auxiliary. This dye is only suitable for manmade fibre. In case of Reactive dyes… Hydrolysis is the main problem in dyeing with Reactive dyes. Only 60 to 70 percent dyes are absorbed in Reactive dyeing. There are also many causes of technical deficiency of reactive dye. Those are described below: Hydrolysis of reactive dyes: Under alkaline condition, reactive dyes react with the terminal hydroxyl group of cellulose. But if the solution of the dye is kept for long time, it’s concentration drops. Then the dye react with the hydroxyl group of water .The reaction of dye with water is called Hydrolysis of reactive dyes. Factors which affect the hydrolysis of the reactive dye: Salt concentration: When the cellulosic textile material is sink into water it convert into negetive charge or anionic charge. But the reactive dye is also convert into anionic charge. So the surface of the cellulosic material repel the dye molecules. To overcome the problem we use electrolite material like salt. It hepls to netralize the negetive ion over the textile material and helps the reactive dye ion to fix on the surface of the materail. As a result If we increase the concentration of the salt hydrolysis of the reactive dye will decrease. pH: If the pH of the medium increase hydrolysis of the reactive dye also increase. This is for, reactive dye ionised more in alkaline medium and as a result it react with hydroxyl group of the water.
Temperature: With the increase of temperature hydrolysis of the reactive dye increases. Substantivity: With the increase of the substantivity hydrolysis of the reactive dye increase. Reactive group of the reactive dye: Hydrolysis of the reactive dye depends on which group does it bears. Vinyl sulphone dye hydrolyize more than the Triazinyl group. Hydrolysis of water: Hydrolysis of the water is also a cause of the technical deficiency of the reactive dye. Remidies of the hydrolysis of the reactive dyes: The highest absorption of the reactive dye is about 70%. To minnimize the more lose of the reactive dye we should maintain proper liquor ratio, proper time and temperature. Even the pH of the emdium is also an important factor to avoid the more wastage of the reactive dye. Conclusion: The dyeing of PCF is a fascinating and tremendous job in the textile processing, but with the help of proper guidance of dye selection, dye combination analysis, pre-diagnosis of dyeing machinery, dyeing auxiliaries the dyeing parameters can be optimized. The tensile strength, surface smoothness of polyester/cotton blend fabric can be significantly improved by the right establishment of kinetic dyeing thermodynamics and which leads to the excellency of a new dyeing era with almost zero defect in shed. P/C blend fabrics were successfully dyed with the physical mixture of D/R dyes by two-bath dyeing process. The novelty of undertake study is successful mixing of the commercially available dyes as is to give complete shade gamut, in powder form which will open up new avenues to dyestuff suppliers to cater to the blend dyeing needs of the textile processors. The work is based on the well established process of dyeing however will emerge in readymade dyes as option to dyers to get rid of cumbersome shade matching at their end. Also, this two-bath dyeing process has potential in offering savings in time, energy, water and labour. possibility of a commercially acceptable dyeing process for P/C blend using the physical mixture of D/R dyes. This research work demonstrates the specific
ANALYSIS OF MARKETING Consumer of the products: FAKIR APPARELS LTD. is a 100% export oriented industry. All the goods produced in this industry are exported into various foreign countries. Name of the main buyers of the products of the industry are given below: 1. TOM TAILOR 2. S. OLIVER 3. H&M 4. POINT ZERO 5. GAP ADULT 6. G-STAR 7. AHLENS Importing countries: The countries which are importing goods from Fakir Apparels Ltd are given below: U.S.A GERMANY SPAIN TURKEY RUSSIA JAPAN SWEDEN THAILAND SCOPE OF MARKETING: As the life style of the people is changing and to keep face with that life style people of the world is seeking for high quality of product at the same time at a low cost. In this case we are lucky to have all the opportunity for the buyer at a low price. As e result our market is spreading all over the world. Now we are not competing with China, Thailand, India which was one time impossible to imagine. We are now not only exporting the knitted products but also the woven is being exported
Marketing Philosophy: Marketing philosophy is a very important factors to sale the products to the buyer. In FAKIR APPARELS LTD. mainly senior marketing officers, merchandiser deals with buyer. There are some fixed buyers of the industry. The buyers give their orders continuously all over the year. The marketing officers and by both side understanding the rate and the order quantity are fixed. Duties& responsibilities of marketing officer: The main duties and responsibilities of a marketing officer are given bellow: To prepare cost sheet by dealing with the buyer. To take different steps by discussing with the high officials and merchandiser. To maintain a regular & good relationship between commercial officer & merchandiser. To maintain a regular communication with the buyers & buying houses. Communicate with the new buyer. Display the criteria of the products. Actually the responsibilities & duties of marketing officer begins from getting order of buyer & ends after receiving goods by the buyer. So he should be always smart, energetic & sincere. Remarks: FAKIR APPARELS LTD. has a well learned marketing & merchandising team. They always communicate with the buyers. The marketing section also looks for the quality & quantity buyers. Importance of the Project: The main goal of our project is to provide information about the reason of using disperse & reactive dyestuff in major textile industry in Bangladesh, different methods using in our industry for cotton dyeing with reactive dyes & for polyester dyeing with disperse dyes, technical deficiency of reactive & disperse dyes during dyeing & causes and remedies of deficiency of reactive & disperse dyes. As these topics are very sensitive for dyeing industries, it is very much important to make a survey. It will be very helpful not only for our studying period but also for our future career. This project also has these importances: 1. To mention the reason of using reactive & disperse dyes in major textile industry. 2. To study on the application of reactive & disperse dyes of a P/C blended fabric. 3. To learn about the technical deficiency of reactive & disperse dyeing
Conclusion Reactive dyes provide substantial benefits over other dyes. As the prevalence of synthetic fibers grow, new reactive groups or approaches may have to be developed to improve the economy and fastness of colorants. The substantivity of reactive dyes for cotton influenced the easy with which the unfixed dye could be removed from the fabric after dyeing, the lower substantivity dyes being removed in larger amounts under milder conditions. Although only a limited number of dyes have been examined, it seems that washing temperatures could be selected to be lower for less substantive dyes, and higher for more substantive dyes. In this respect, the paper chromatography test was most useful in providing a quick and inexpensive measure of the substantivity of the dye. This test would also allow rapid selection of dyes, to be used in combination, which would dye cotton with little change in hue as the depth of the dyeing gradually develops. This would give the dyer much more control in colour matching. Future studies should confirm these initial results. We have completed our industrial attachment from FAKIR APPARELS LTD. During our two month long industrial training at FAL, we got the impression that this factory is one of the modern export oriented composite knit garments composite in our country. This factory does not compromise in case of quality. So they have established online and offline quality control of each product. Besides they also use good quality yarn, dyes and chemicals in their production process. Specially they are mostly use good quality “Reactive Dye & Disperse Dye” for their production process. Due to using good quality “Reactive Dye & Disperse Dye” it has earned a “ very good reputation” in foreign market for its quality product over many other export oriented composite textile mills in our country. It has very well educated & technically experienced manpower to get rid of any defect in production process.
SOME SUGGESTIONS: More skilled labor should be used in a project and the overall efficiency will increase. We should always follow up the Colour mixture rule . Dyeing floor should keep always neat and clean. It kept wet after unloading the fabric from the dyeing machine specially, for Athena. Water must be swept time to time. We should always maintain the M:L ratio. During the transport of the fabric and during the loading of the m/c, fabrics get soiled due to their drawing over the floor. This makes the fabric/part of the fabric dirty. It may require more scouring/bleaching agent or may create stain. We should always use the good quality reactive dyes so that all the fastness properties is to be supported. Due to the pressure of higher production some times machine operators do not maintain accurate time according to the actual process so that less quality product is produced and may reject. So our suggestion is to increase machine and reduce the pressure on the operator. We should colour dozing slowly for even dyeing. We should soda & salt dozing carefully to avoid dyeing fault. We Should increase understanding between the top level personal and floor level personal. The m/c stoppage time should be analyzed and minimized. The maintenance should be carried out when the m/c is out of action (Wherever possible) and routine maintenance should be carried out regularly. In knitting and finishing section every workers should use mask to make protect them from fly. Otherwise the exhaust air system should be more effective. Workers are not interested to wear their gown & hand gloves they must need to use it. In the Laboratory there is needed the accurate dyes percentage calculation otherwise production may be not completed within schedule time. Operator should follow the overall process carefully The spectrophotometer is needed all time running other wise problem will be created when make a recipe.
Limitations of the report : Because of secrecy act, the data on costing and marketing activities have not been supplied. We had a very limited time. In spite of our willing to study more it was not possible to do so. Some points in different Sections are not included as these were not available. It is not possible to hold the whole thing of a textile industry in such a small frame as this report. So, try to my hard to summarize all the information that are provided.
