Its a knowledge based presentation of famous denim dying sulphur dye. Feel free to read and shear with others. You may also find your desired presentation topics on my other slides.
Thank you.
Azoic dyes are produced by reacting a diazo-component or base salt with a coupling component like naphthol. This reaction forms an insoluble azo group that produces the dye within the fiber, resulting in excellent washing fastness. Azoic dyes can be used to dye cellulose fibers like cotton. The dyeing process involves three steps: naphtholation, diazotization, and coupling. Azoic dyes form an insoluble color product within the fabric, making them different from azo dyes which use a soluble azo group.
Chemicals and Auxiliaries used in Textile Wet ProcessingMashrur Wasity
This document discusses various chemicals and auxiliaries used in textile wet processing. It defines auxiliaries as chemicals that help processing operations like preparation, dyeing and printing work more efficiently. Some common auxiliaries mentioned include surfactants, wetting agents, sequestering agents, dispersing agents and emulsifiers. Basic chemicals used in wet processing like acids, bases, salts, oxidizing and reducing agents are also discussed. The roles and examples of various chemicals are provided in concise points.
Sulphur dyes contain disulfide linkages and are used to produce black, brown, and other dark shades on cellulosic materials like cotton. They are water-insoluble so must be converted to a water-soluble leuco form using a reducing agent before application. After dyeing, an oxidizing agent turns the dye back to its insoluble form within the fiber. Issues like poor fastness, bronzing, and material tendering can occur but have corrective actions like ensuring complete dissolution and reaction of the dye and proper washing after dyeing.
This document discusses the properties, mechanisms, classification, and application of sulphur dyes. Sulphur dyes contain sulphur linkages, are insoluble in water but soluble in sodium sulphide. During dyeing, sodium sulphide converts the dye to soluble thiols which penetrate the fiber and are oxidized back to the insoluble dye. Sulphur dyes are classified as sulphur, leuco sulphur, or solubilized. Dyeing involves preparing a dye bath and dyeing cotton at a boil. Aftertreatment can improve fastness. Disadvantages include bronzing shades and tendering of sulphur black dyed goods over time.
Vat dyes are insoluble in water but can be converted to soluble leuco compounds using reducing agents like sodium hydrosulphite and caustic soda. These leuco compounds are applied to cotton and oxidized back to insoluble dyes. Vat dyes are classified by application temperature and chemical requirements, with IK requiring the lowest temperatures and chemicals and IN-Special requiring the highest. The vat dyeing process involves vatting to solubilize the dye, dyeing to apply it to cotton, oxidation to fix it, and after treatment including soaping to improve fastness.
Vat dyes are insoluble natural or synthetic dyes that are converted to their soluble leuco form using a reducing agent like sodium hydrosulfite. This allows the dye to penetrate cellulose fibers during the dyeing process. After penetration, the fabric is oxidized, converting the dye back to its insoluble form within the fibers. Key steps are vatting to solubilize the dye, dyeing to allow penetration, and oxidation to fix the dye in the fibers. Vat dyes provide excellent washing fastness due to being locked inside the fibers. However, they are more difficult and costly to apply than other dyes.
Azoic dyes are produced by reacting a diazo-component or base salt with a coupling component like naphthol. This reaction forms an insoluble azo group that produces the dye within the fiber, resulting in excellent washing fastness. Azoic dyes can be used to dye cellulose fibers like cotton. The dyeing process involves three steps: naphtholation, diazotization, and coupling. Azoic dyes form an insoluble color product within the fabric, making them different from azo dyes which use a soluble azo group.
Chemicals and Auxiliaries used in Textile Wet ProcessingMashrur Wasity
This document discusses various chemicals and auxiliaries used in textile wet processing. It defines auxiliaries as chemicals that help processing operations like preparation, dyeing and printing work more efficiently. Some common auxiliaries mentioned include surfactants, wetting agents, sequestering agents, dispersing agents and emulsifiers. Basic chemicals used in wet processing like acids, bases, salts, oxidizing and reducing agents are also discussed. The roles and examples of various chemicals are provided in concise points.
Sulphur dyes contain disulfide linkages and are used to produce black, brown, and other dark shades on cellulosic materials like cotton. They are water-insoluble so must be converted to a water-soluble leuco form using a reducing agent before application. After dyeing, an oxidizing agent turns the dye back to its insoluble form within the fiber. Issues like poor fastness, bronzing, and material tendering can occur but have corrective actions like ensuring complete dissolution and reaction of the dye and proper washing after dyeing.
This document discusses the properties, mechanisms, classification, and application of sulphur dyes. Sulphur dyes contain sulphur linkages, are insoluble in water but soluble in sodium sulphide. During dyeing, sodium sulphide converts the dye to soluble thiols which penetrate the fiber and are oxidized back to the insoluble dye. Sulphur dyes are classified as sulphur, leuco sulphur, or solubilized. Dyeing involves preparing a dye bath and dyeing cotton at a boil. Aftertreatment can improve fastness. Disadvantages include bronzing shades and tendering of sulphur black dyed goods over time.
Vat dyes are insoluble in water but can be converted to soluble leuco compounds using reducing agents like sodium hydrosulphite and caustic soda. These leuco compounds are applied to cotton and oxidized back to insoluble dyes. Vat dyes are classified by application temperature and chemical requirements, with IK requiring the lowest temperatures and chemicals and IN-Special requiring the highest. The vat dyeing process involves vatting to solubilize the dye, dyeing to apply it to cotton, oxidation to fix it, and after treatment including soaping to improve fastness.
Vat dyes are insoluble natural or synthetic dyes that are converted to their soluble leuco form using a reducing agent like sodium hydrosulfite. This allows the dye to penetrate cellulose fibers during the dyeing process. After penetration, the fabric is oxidized, converting the dye back to its insoluble form within the fibers. Key steps are vatting to solubilize the dye, dyeing to allow penetration, and oxidation to fix the dye in the fibers. Vat dyes provide excellent washing fastness due to being locked inside the fibers. However, they are more difficult and costly to apply than other dyes.
The document discusses the process of singeing textiles. Singeing involves burning off protruding fibers from fabric surfaces to improve smoothness and luster. It can be done using gas singeing machines, which pass fabric over flames, or hot plate/roller machines. Key factors that affect singeing include flame intensity, fabric speed and temperature, and fiber type. Singeing removes fuzz to create a uniform, lustrous surface that reflects light evenly.
The document discusses the production of denim fabric using slasher dyeing. It describes the slasher dyeing process which continuously passes warp yarns through indigo dye liquor troughs to dye the yarns on the warp beam. This allows for dyeing and sizing in a single operation. The document also provides details on the types of yarns, chemicals, and processes used, including scouring, dyeing with indigo and sulfur black, and sizing to strengthen and protect the yarns during weaving.
This presentation discusses direct dyes, which are water-soluble dyes used to dye cellulosic materials like cotton directly. There are two major types of direct dyes: anionic direct dyes, which are used for paper coloring and shade correction, and cationic direct dyes. Direct dyes have properties like water solubility and being anionic in nature. They dye materials through weak hydrogen and van der Waals bonding in alkaline conditions. The dyeing process involves dissolving the dye in boiling water with electrolytes before applying it to materials and boiling for 30-45 minutes. Direct dyes provide duller colors than reactive dyes and have lower wash fastness. They are used for applications where high fastness is
The document discusses the desizing process of cotton fabric. Desizing involves removing the size material that was applied to warp yarns during weaving to prevent breakage. This is done to increase the fabric's absorbency and affinity for chemicals in subsequent processing. Common methods of desizing include acid desizing using dilute acids, enzymatic desizing using amylase enzymes to hydrolyze starch, and oxidative desizing using oxidizing agents. The key objectives of desizing are to remove the size material, increase wettability and absorbency of the fabric to prepare it for downstream processes like dyeing and printing.
Reactive dyes are organic dyes that form covalent bonds with cellulose fibers. They were first commercially produced in 1956 and have advantages like excellent color fastness and ease of washing. Reactive dyes contain three parts - a chromophore for color, a reactive group that bonds to fibers, and a bridging group connecting these. Dyeing involves exhaustion of dye onto fibers, fixation through alkaline conditions forming covalent bonds, and washing unfixed dye away. Reactive dyeing gives very colorfast results due to the strong covalent bonds formed.
The document summarizes the general structure and properties of reactive dyes. Reactive dyes have a D-B-G-X structure, where D is the dye/chromogen, B is the bridging group, G is the reactive group, and X is the actual reactive functional group. Reactive dyes form covalent bonds with cellulosic fibers and have good wash and light fastness as a result. They are classified based on the number of reactive groups and dyeing temperature. Factors like pH, temperature, electrolyte concentration influence the dyeing process. Defects can occur but are remedied by washing or chemical treatment.
MX dyes are a family of "cold" reactive dyes first developed by Imperial Chemical Industries of Britain. They are very popular for dyeing cellulose fibers like cotton. MX dyes are less commonly used by industrial dyers due to their high reactivity making them harder to control and their relatively high cost. Care should be taken when using MX dyes due to the potential to cause respiratory allergies from inhaling dye dust.
This document discusses dyeing in textiles, including different types of dyes, dye classification systems, dyeing parameters and calculations, auxochromes, chromophores, direct dyes, vat dyes, acidic dyes, basic dyes, dyeing faults, and dyeing remedies. It covers natural and synthetic dyes, factors that influence dyeing like temperature and pH, functional groups that increase dye absorption, chromophores that determine color, direct dye mechanisms and applications, vat dye mechanisms and applications, and remedies for uneven or inconsistent dyeing.
The document discusses the scouring process, which involves removing natural and added impurities from textile fibers. There are three main methods for removing impurities: saponification, emulsification, and solubilization. Saponification converts impurities like oils and fats into water-soluble soaps. Emulsification forms suspensions of non-saponifiable impurities. Solubilization dissolves substances like pectin and proteins into soluble salts. The scouring process aims to remove all impurities and leave the fibers highly absorbent without damage. Common scouring agents include alkaline solutions, surfactants, and sometimes organic solvents.
1. Dyeing polyester/cotton blend fabrics using reactive disperse dyes in supercritical carbon dioxide has several advantages over conventional dyeing methods.
2. Supercritical carbon dioxide acts as a solvent for the hydrophobic disperse dyes and allows for deep penetration and homogeneous dyeing of the polyester fibers.
3. The process is more environmentally friendly as supercritical carbon dioxide is non-toxic, non-flammable and can be recycled in a closed system without disposal issues.
This document discusses the process of dyeing textiles. It explains that there are three main types of dyeing: fiber, yarn and fabric dyeing. The dyeing process involves successive stages including dispersing dye in a dye bath, diffusion of dye onto and into the fiber substrate, and bonding between dye and fiber molecules. Dyes are also classified by their application method and chemical structure. Proper control of dye bath parameters like liquor ratio, electrolyte concentration, pH and temperature are important to ensure efficient dye absorption and an even color. Modern industrial dyeing is automated but still aims to produce textiles with homogeneous color in an economic manner with good colorfastness.
Vat dyes are water-insoluble dyes that can be converted to a water-soluble form through chemical reduction. They were first developed in the 1850s as synthetic dyes and include indigo dye. The vat dyeing process involves three steps - vatting to convert the dye to its soluble leuco form, oxidation to convert it back to insoluble form in the fiber, and after treatment. Vat dyes have high color fastness but more limited shades than other dyes and their application process is complex and time-consuming.
1. The document discusses dyeing polyester fabric with disperse dyes and different dyeing methods, including using a carrier or high temperature dyeing.
2. It explains that a carrier helps the disperse dye penetrate polyester fibers better than normal dyeing, while high temperature dyeing at 130C can achieve deep shades without a carrier.
3. The experiments compare dyeing polyester with a carrier versus high temperature dyeing, and how being heat set first affects dye uptake, finding that heat setting before dyeing reduces uptake while carriers or high heat increase it.
This document discusses the scouring and bleaching processes for various natural and man-made fibers. It explains that wool requires a mild scouring process due to its sensitivity to alkali. Scouring of wool uses sodium carbonate or ammonium carbonate at below boiling temperatures. Bleaching can be done with reducing agents like sodium bisulfite or hydrogen peroxide, which produces a permanent whiteness. For silk, degumming using hot soap solution is required to remove the sericin gum. Hydrogen peroxide bleaching is preferred for silk. Man-made fibers require milder scouring, and polyester rarely needs bleaching, while nylon and acrylic can be bleached using sodium chlor
The document provides information about reactive dyes, including:
- Reactive dyes form covalent bonds with fiber polymers through reactive groups, giving excellent wash and light fastness.
- Important reactive groups include triazine, vinyl sulfone, and halogen groups.
- Reactive dyes were invented in 1956 and became popular for their bright colors, low temperature dyeing, and simple process.
- Common application methods are pad-batch and pad-dry processes at low temperatures. Proper pH, electrolyte, alkali, and time are required for effective dye fixation to the fiber.
This document provides information about sulfur dyeing. It discusses that sulfur dyes are inexpensive reaction mixtures that are chemically reduced prior to application and reoxidized after dyeing cotton or cellulose fibers. It also describes the two-stage dyeing process where the insoluble sulfur dye is converted to a water-soluble leuco form using sodium sulfide, which is absorbed by the fibers during dyeing and then reoxidized. The document provides details on the dyeing process and recipes used for cotton fabrics as well as some common faults and their remedies. It discusses the advantages of sulfur dyes being inexpensive while providing deep shades with good fastness properties.
Acrylic fiber is produced from polyacrylonitrile and is difficult to dye due to its lack of affinity for dyes. To aid dyeing, acrylic fibers contain 15% of a co-monomer like acrylic acid that makes the fiber negatively charged. Cationic or basic dyes have good affinity for acrylic fibers due to electrostatic interactions between the positive dye ions and negative fiber charges. Dyeing with cationic dyes involves first dissolving the dye in a bath containing acetic acid and other compounds like sodium acetate and Glauber's salt. The fiber is then treated in this dye bath at increasing temperatures over an hour to evenly disperse the dye into the fiber.
This document discusses the dyeing of polyamide fibers like wool, silk, and nylon. It explains the dyeing mechanisms and how the structure of polyamide fibers allows them to be dyed using different dye classes like acid dyes, chrome dyes, and reactive dyes depending on the desired properties like colorfastness. Factors like pH, temperature, and use of leveling agents affect dye uptake and uniformity. Different types of acid dyes provide varying colorfastness and are suitable for different applications depending on those properties.
This document provides information on chemicals used in various textile wet processing stages. It discusses chemicals used in pre-treatment processes like desizing, scouring, bleaching and mercerization. Specific chemicals are listed along with their functions in each process. The document also covers latest specialty chemicals used in pre-treatment like cracking agents, bleach processors and surfactants. Finally, it briefly introduces dyes and dyeing process.
This document provides information about reactive dyes and disperse dyes. It discusses the dyeing conditions for different types of dyes including acid, basic, direct, disperse, and reactive dyes. It also summarizes the types and properties of reactive dyes and disperse dyes, as well as the dyeing processes for polyester fibers using disperse dyes. Finally, it lists some of the author's textile-related Facebook pages for additional information.
Aniline black dyeing provides a jet black color for cotton materials in an economical way. It involves impregnating the textile with a solution containing an aniline salt, oxidizing agent, and acid. Upon drying and steaming, an initial black color forms but it is "greenable," turning bottle green upon reduction. A subsequent chroming treatment with dichromate solution produces an ungreenable black shade with good fastness properties. While natural dyes have advantages like being renewable and non-toxic, they have limitations in availability, color yield, reproducibility, and fastness properties compared to synthetic dyes. Common natural dyes include indigo, madder, lac, and turmeric, which are classified as vat
The document discusses the process of singeing textiles. Singeing involves burning off protruding fibers from fabric surfaces to improve smoothness and luster. It can be done using gas singeing machines, which pass fabric over flames, or hot plate/roller machines. Key factors that affect singeing include flame intensity, fabric speed and temperature, and fiber type. Singeing removes fuzz to create a uniform, lustrous surface that reflects light evenly.
The document discusses the production of denim fabric using slasher dyeing. It describes the slasher dyeing process which continuously passes warp yarns through indigo dye liquor troughs to dye the yarns on the warp beam. This allows for dyeing and sizing in a single operation. The document also provides details on the types of yarns, chemicals, and processes used, including scouring, dyeing with indigo and sulfur black, and sizing to strengthen and protect the yarns during weaving.
This presentation discusses direct dyes, which are water-soluble dyes used to dye cellulosic materials like cotton directly. There are two major types of direct dyes: anionic direct dyes, which are used for paper coloring and shade correction, and cationic direct dyes. Direct dyes have properties like water solubility and being anionic in nature. They dye materials through weak hydrogen and van der Waals bonding in alkaline conditions. The dyeing process involves dissolving the dye in boiling water with electrolytes before applying it to materials and boiling for 30-45 minutes. Direct dyes provide duller colors than reactive dyes and have lower wash fastness. They are used for applications where high fastness is
The document discusses the desizing process of cotton fabric. Desizing involves removing the size material that was applied to warp yarns during weaving to prevent breakage. This is done to increase the fabric's absorbency and affinity for chemicals in subsequent processing. Common methods of desizing include acid desizing using dilute acids, enzymatic desizing using amylase enzymes to hydrolyze starch, and oxidative desizing using oxidizing agents. The key objectives of desizing are to remove the size material, increase wettability and absorbency of the fabric to prepare it for downstream processes like dyeing and printing.
Reactive dyes are organic dyes that form covalent bonds with cellulose fibers. They were first commercially produced in 1956 and have advantages like excellent color fastness and ease of washing. Reactive dyes contain three parts - a chromophore for color, a reactive group that bonds to fibers, and a bridging group connecting these. Dyeing involves exhaustion of dye onto fibers, fixation through alkaline conditions forming covalent bonds, and washing unfixed dye away. Reactive dyeing gives very colorfast results due to the strong covalent bonds formed.
The document summarizes the general structure and properties of reactive dyes. Reactive dyes have a D-B-G-X structure, where D is the dye/chromogen, B is the bridging group, G is the reactive group, and X is the actual reactive functional group. Reactive dyes form covalent bonds with cellulosic fibers and have good wash and light fastness as a result. They are classified based on the number of reactive groups and dyeing temperature. Factors like pH, temperature, electrolyte concentration influence the dyeing process. Defects can occur but are remedied by washing or chemical treatment.
MX dyes are a family of "cold" reactive dyes first developed by Imperial Chemical Industries of Britain. They are very popular for dyeing cellulose fibers like cotton. MX dyes are less commonly used by industrial dyers due to their high reactivity making them harder to control and their relatively high cost. Care should be taken when using MX dyes due to the potential to cause respiratory allergies from inhaling dye dust.
This document discusses dyeing in textiles, including different types of dyes, dye classification systems, dyeing parameters and calculations, auxochromes, chromophores, direct dyes, vat dyes, acidic dyes, basic dyes, dyeing faults, and dyeing remedies. It covers natural and synthetic dyes, factors that influence dyeing like temperature and pH, functional groups that increase dye absorption, chromophores that determine color, direct dye mechanisms and applications, vat dye mechanisms and applications, and remedies for uneven or inconsistent dyeing.
The document discusses the scouring process, which involves removing natural and added impurities from textile fibers. There are three main methods for removing impurities: saponification, emulsification, and solubilization. Saponification converts impurities like oils and fats into water-soluble soaps. Emulsification forms suspensions of non-saponifiable impurities. Solubilization dissolves substances like pectin and proteins into soluble salts. The scouring process aims to remove all impurities and leave the fibers highly absorbent without damage. Common scouring agents include alkaline solutions, surfactants, and sometimes organic solvents.
1. Dyeing polyester/cotton blend fabrics using reactive disperse dyes in supercritical carbon dioxide has several advantages over conventional dyeing methods.
2. Supercritical carbon dioxide acts as a solvent for the hydrophobic disperse dyes and allows for deep penetration and homogeneous dyeing of the polyester fibers.
3. The process is more environmentally friendly as supercritical carbon dioxide is non-toxic, non-flammable and can be recycled in a closed system without disposal issues.
This document discusses the process of dyeing textiles. It explains that there are three main types of dyeing: fiber, yarn and fabric dyeing. The dyeing process involves successive stages including dispersing dye in a dye bath, diffusion of dye onto and into the fiber substrate, and bonding between dye and fiber molecules. Dyes are also classified by their application method and chemical structure. Proper control of dye bath parameters like liquor ratio, electrolyte concentration, pH and temperature are important to ensure efficient dye absorption and an even color. Modern industrial dyeing is automated but still aims to produce textiles with homogeneous color in an economic manner with good colorfastness.
Vat dyes are water-insoluble dyes that can be converted to a water-soluble form through chemical reduction. They were first developed in the 1850s as synthetic dyes and include indigo dye. The vat dyeing process involves three steps - vatting to convert the dye to its soluble leuco form, oxidation to convert it back to insoluble form in the fiber, and after treatment. Vat dyes have high color fastness but more limited shades than other dyes and their application process is complex and time-consuming.
1. The document discusses dyeing polyester fabric with disperse dyes and different dyeing methods, including using a carrier or high temperature dyeing.
2. It explains that a carrier helps the disperse dye penetrate polyester fibers better than normal dyeing, while high temperature dyeing at 130C can achieve deep shades without a carrier.
3. The experiments compare dyeing polyester with a carrier versus high temperature dyeing, and how being heat set first affects dye uptake, finding that heat setting before dyeing reduces uptake while carriers or high heat increase it.
This document discusses the scouring and bleaching processes for various natural and man-made fibers. It explains that wool requires a mild scouring process due to its sensitivity to alkali. Scouring of wool uses sodium carbonate or ammonium carbonate at below boiling temperatures. Bleaching can be done with reducing agents like sodium bisulfite or hydrogen peroxide, which produces a permanent whiteness. For silk, degumming using hot soap solution is required to remove the sericin gum. Hydrogen peroxide bleaching is preferred for silk. Man-made fibers require milder scouring, and polyester rarely needs bleaching, while nylon and acrylic can be bleached using sodium chlor
The document provides information about reactive dyes, including:
- Reactive dyes form covalent bonds with fiber polymers through reactive groups, giving excellent wash and light fastness.
- Important reactive groups include triazine, vinyl sulfone, and halogen groups.
- Reactive dyes were invented in 1956 and became popular for their bright colors, low temperature dyeing, and simple process.
- Common application methods are pad-batch and pad-dry processes at low temperatures. Proper pH, electrolyte, alkali, and time are required for effective dye fixation to the fiber.
This document provides information about sulfur dyeing. It discusses that sulfur dyes are inexpensive reaction mixtures that are chemically reduced prior to application and reoxidized after dyeing cotton or cellulose fibers. It also describes the two-stage dyeing process where the insoluble sulfur dye is converted to a water-soluble leuco form using sodium sulfide, which is absorbed by the fibers during dyeing and then reoxidized. The document provides details on the dyeing process and recipes used for cotton fabrics as well as some common faults and their remedies. It discusses the advantages of sulfur dyes being inexpensive while providing deep shades with good fastness properties.
Acrylic fiber is produced from polyacrylonitrile and is difficult to dye due to its lack of affinity for dyes. To aid dyeing, acrylic fibers contain 15% of a co-monomer like acrylic acid that makes the fiber negatively charged. Cationic or basic dyes have good affinity for acrylic fibers due to electrostatic interactions between the positive dye ions and negative fiber charges. Dyeing with cationic dyes involves first dissolving the dye in a bath containing acetic acid and other compounds like sodium acetate and Glauber's salt. The fiber is then treated in this dye bath at increasing temperatures over an hour to evenly disperse the dye into the fiber.
This document discusses the dyeing of polyamide fibers like wool, silk, and nylon. It explains the dyeing mechanisms and how the structure of polyamide fibers allows them to be dyed using different dye classes like acid dyes, chrome dyes, and reactive dyes depending on the desired properties like colorfastness. Factors like pH, temperature, and use of leveling agents affect dye uptake and uniformity. Different types of acid dyes provide varying colorfastness and are suitable for different applications depending on those properties.
This document provides information on chemicals used in various textile wet processing stages. It discusses chemicals used in pre-treatment processes like desizing, scouring, bleaching and mercerization. Specific chemicals are listed along with their functions in each process. The document also covers latest specialty chemicals used in pre-treatment like cracking agents, bleach processors and surfactants. Finally, it briefly introduces dyes and dyeing process.
This document provides information about reactive dyes and disperse dyes. It discusses the dyeing conditions for different types of dyes including acid, basic, direct, disperse, and reactive dyes. It also summarizes the types and properties of reactive dyes and disperse dyes, as well as the dyeing processes for polyester fibers using disperse dyes. Finally, it lists some of the author's textile-related Facebook pages for additional information.
Aniline black dyeing provides a jet black color for cotton materials in an economical way. It involves impregnating the textile with a solution containing an aniline salt, oxidizing agent, and acid. Upon drying and steaming, an initial black color forms but it is "greenable," turning bottle green upon reduction. A subsequent chroming treatment with dichromate solution produces an ungreenable black shade with good fastness properties. While natural dyes have advantages like being renewable and non-toxic, they have limitations in availability, color yield, reproducibility, and fastness properties compared to synthetic dyes. Common natural dyes include indigo, madder, lac, and turmeric, which are classified as vat
Nitric acid is a colorless liquid that is strongly acidic and corrosive. It is produced industrially through the Ostwald process, which involves a three-step oxidation of ammonia using air over a platinum catalyst. Nitric acid is used to produce fertilizers, explosives like TNT, and other chemicals. It is also used in metal purification and to make aqua regia for dissolving noble metals. Proper precautions must be taken when handling nitric acid due to its corrosive nature and potential to cause burns or lung damage.
This document discusses direct dyeing processes. It covers:
1. Direct dyes are initially dyed slowly for even dyeing, and factors like heat, salt, and dye properties affect the dyeing rate.
2. Class C dyes are large and have more sulfate groups, so require heat and salt/temperature control for movement during dyeing.
3. The dyeing process involves chemicals like salt, soda ash, and softeners, with machines dyed based on material-liquor ratio and capacity. Proper preparation and application of dyes and after-treatments like fixation are described.
Disperse dyes are used to dye polyester fabrics. They are not soluble in water and must be dispersed using a dispersing agent. There are various types of disperse dyes classified by their energy level, which determines their suitability for different dyeing processes like high temperature exhaust dyeing or printing. Key factors for disperse dyes include good dispersion stability, build-up, and fastness properties. Dyeing processes for polyester include batchwise, high temperature, carrier, and continuous dyeing. When dyeing polyester/cellulose blends, both portions can be dyed together or separately in one or two baths. Continuous dyeing uses pad-steam methods with thermosol fixation. Pro
The document discusses various methods for printing acrylic fabric, including direct, discharge, and resist styles. Direct printing uses cationic dyes and requires pretreatment before steaming to fix the dyes. Discharge printing uses a colored ground of dischargeable dyes with illuminating colors of non-dischargeable dyes and a discharging agent like tin chloride. Blends of acrylic and other fibers like cellulose can be printed with desperse or reactive dyes. Recent developments include digital printing of acrylic with conventional inkjet printers and surface modification to improve dyeability.
The document discusses bleaching processes for textile fibres. It describes the purpose of bleaching as removing natural coloration and impurities from natural and man-made fibres. The key bleaching agents discussed are oxidizing agents like chlorine and hydrogen peroxide, and reducing agents like sodium sulphite. The document provides details on bleaching with sodium hypochlorite, hydrogen peroxide, and chlorine, including bleaching recipes, reactions, and advantages and disadvantages of each method. Absorbency and whiteness tests for evaluating bleaching effectiveness are also summarized.
This document provides information about nitric acid, including its physical and chemical properties, uses, manufacturing process, and production in Pakistan. It describes nitric acid as a colorless liquid used to make fertilizers, dyes, and explosives. Three common industrial methods for producing nitric acid are outlined - the Chile saltpeter method using sodium nitrate, Birkeland-Eyde's method using air, and Ostwald's method using ammonia. Safety precautions for handling nitric acid and first aid measures for exposure are also summarized.
The kraft process, also known as the sulfate process, is an industrial process that converts wood into pulp consisting mainly of pure cellulose fibers. It involves treating wood chips with a mixture of sodium hydroxide and sodium sulfide known as liquor. This breaks the bonds linking lignin to the cellulose. The process includes impregnating chips with white liquor, cooking them to remove lignin, recovering chemicals from the spent liquor, screening and washing the pulp, and sometimes bleaching it to produce high brightness pulp. The kraft process was invented in the 1870s and is now the dominant pulping process worldwide.
This chemistry lab experiment involves the titration of hydrated oxalic acid with potassium manganate in the presence of acid. The purpose is to determine the value of x in H2C2O4.xH2O. Key steps include adding oxalic acid, sulfuric acid, and water to a flask, heating the solution, and titrating with potassium manganate from a burette until the solution turns from colorless to pale pink. Based on the volume of potassium manganate used, the value of x was calculated to be 1.95 mol. Safety precautions for handling acids and oxidizers are also outlined.
1. The document discusses sulphur dyes, including their properties, dyeing process, advantages, defects and remedies.
2. Sulphur dyes contain sulphur linkages and are converted to water-soluble forms using reducing agents before dyeing cellulosic fabrics.
3. The dyeing process involves a reducing step to dissolve the dyes followed by an oxidizing step to convert them back to insoluble forms for good fastness.
1. The document discusses sulphur dyes, including their properties, dyeing process, advantages, defects and remedies.
2. Sulphur dyes contain sulphur linkages and are converted to water-soluble forms using reducing agents before dyeing cellulosic fabrics.
3. The dyeing process involves a reducing step to dissolve the dyes followed by an oxidizing step to reconstruct the insoluble dye form for good fastness.
Nitric acid is a strong acid that is colorless as a pure liquid but commercial nitric acid may be yellowish-brown. It is produced through a three-stage process involving the oxidation of ammonia over a platinum catalyst. It has many industrial uses including in explosives, fertilizers, dyes, and others. When reacted with metals, it produces metal nitrates and oxides of nitrogen. It is both an oxidizing and acidifying agent that can cause explosions when reacted with some metals like sodium or potassium. The document provides details on the manufacture, properties, uses, and reactions of nitric acid.
This document provides information about vat dyes, including:
- Vat dyes are one of the oldest dyes used for thousands of years, originally produced from plants but now mainly produced synthetically.
- The name "vat" comes from the large wooden vessels used to apply the dyes, which are water-insoluble and require a vatting process to make them soluble for dyeing fabrics.
- Vat dyed products are popular for garments like denim which fade gradually with wear, adding value.
- The document outlines the classification, trade names, dyeing mechanisms and processes, sample calculations, materials/equipment used, and pretreatment steps for vat dyeing.
This document discusses vat dyes, which are insoluble in water but can be solubilized by reduction into leuco compounds. It defines vat dyes and describes their general characteristics, including that they are applied to fabric in a reduced, soluble form and reoxidize upon exposure to air. The document also classifies vat dyes and outlines the steps of vat dyeing techniques, including vatting, oxidation, and after-treatment. It provides examples of indigo and anthraquinone vat dyes and how their chemical structures relate to solubility.
Nitric acid is a strong acid that is colorless as a pure liquid but commercial samples may appear yellowish. It is highly corrosive and a strong oxidizer. Nitric acid is produced industrially via the Ostwald process, which involves ammonia oxidation over a platinum catalyst in three steps: primary oxidation to nitric oxide, secondary oxidation to nitrogen dioxide, and absorption of nitrogen dioxide in water to form nitric acid. Nitric acid has many industrial and laboratory uses including fertilizer and explosive production.
Similar to Sulphur dye and it's application on textiles (20)
Applications of Supercritical Fluid TechnologyAbir Hasan
This presentation is based on supercritical fluid technology and its applications on various sections specially textile. Feel free to read and share with others. You may find your desired topics on my other slides.
Thank you.
Geotextile and it's application on BangladeshAbir Hasan
Detailed concept on geotextile- its evolution, application, current benefits received by Bangladesh and future opportunities for making sustainable environment. Feel free to read and share with others. You may find your desired topics on my other slides.
Thank you.
Brief discussion on overall knowledge about textile printing process- types, process, methods. Feel free to read and share with others. You may also find your desired presentation topics on my other slides.
Thank you.
Concept on hardness test conducted on materialAbir Hasan
Conceptual knowledge on hardness test performed on different types of material. Feel free to read and share with others. You may also find your desired presentation topics on my other slides.
Thank you.
Textile & Environmental Management SystemAbir Hasan
Comprehensive knowledge about ISO 14000 series certificate-its requirements and steps for attainment. Feel free to read and share with others. You may also find your desired presentation topics on my other slides.
Thank you.
Application of computer in textile industryAbir Hasan
A detailed discussion about the application of computer in textile industries. Feel free to read and share with others. You may also find your desired presentation topics on my other slides.
Thank you.
This a case study presentation is based on centralization- whether it is helping us or creating pressure in our day to day lives. Feel free to read and share with others. You may also find your desired presentation topic on my other slides.
Thank you.
Different types of circular knitting machinesAbir Hasan
Its a presentation based on the most commonly used circular knitting machine - its types, difference and usage. Feel free to read and share with others. You may also find your desired presentation topic on my other slides.
Thank you.
Challenges of textile industry and ways to resolveAbir Hasan
Its a detailed analysis of the current challenges of textile industry in Bangladesh and my recommendation for it. Feel free to read and share with others. You may also find your desired presentation topic on my other slides.
Thank you.
An analysis presentation for enthusiastic and knowledge learner based on RAM and ROM its application, difference and history. Feel free to read and share with others. You may also find your desired presentation topic on my other slides.
Thank you.
Based on detailed analysis of RMG condition of Bangladesh in 2020. Feel free to read and share with others. You may also find your desired presentation topic on my other slides.
Thank you.
Its an analysis presentation about generator- its types, usage, basic parts and idea of its futuristic development. Feel free to read and share with others. You may also find your desired presentation topics on my other slides.
Thank you.
The document discusses plain weave, which is the most basic type of weave. It has a simple crisscross pattern formed by warping the warp and weft threads in an alternating order. Plain weave is very strong and produces fabrics that are identical on both sides. It comprises a high percentage of total woven fabric production and is used to make fashion and furnishing fabrics.
Its a detailed analysis of various types of yarn, its usage and benefits. Feel free to read and share with others. You may also find your desired presentation topic on my other slides.
Thank you.
This document provides information about flame retardant and flame proof textiles. It discusses the difference between flameproof textiles, which are inherently resistant to burning, and flame retardant textiles, which are treated with chemicals to resist burning. The document outlines various flame retardant chemical treatment processes and testing methods used to evaluate flame resistance. It notes some limitations of flame retardant textiles and concludes by emphasizing the importance of flame resistance for safety.
Its a brief discussion about the liberation war museum of Bangladesh - its importance, solemnity and the sacrifice, struggle and bravery of our brave freedom fighters for whom we are proud of.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELgerogepatton
As digital technology becomes more deeply embedded in power systems, protecting the communication
networks of Smart Grids (SG) has emerged as a critical concern. Distributed Network Protocol 3 (DNP3)
represents a multi-tiered application layer protocol extensively utilized in Supervisory Control and Data
Acquisition (SCADA)-based smart grids to facilitate real-time data gathering and control functionalities.
Robust Intrusion Detection Systems (IDS) are necessary for early threat detection and mitigation because
of the interconnection of these networks, which makes them vulnerable to a variety of cyberattacks. To
solve this issue, this paper develops a hybrid Deep Learning (DL) model specifically designed for intrusion
detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
at finding smart grid intrusions than other deep learning algorithms used for classification. In addition,
our proposed approach improves accuracy, precision, recall, and F1 score, achieving a high detection
accuracy rate of 99.50%.
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
Slides from talk presenting:
Aleš Zamuda: Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapter and Networking.
Presentation at IcETRAN 2024 session:
"Inter-Society Networking Panel GRSS/MTT-S/CIS
Panel Session: Promoting Connection and Cooperation"
IEEE Slovenia GRSS
IEEE Serbia and Montenegro MTT-S
IEEE Slovenia CIS
11TH INTERNATIONAL CONFERENCE ON ELECTRICAL, ELECTRONIC AND COMPUTING ENGINEERING
3-6 June 2024, Niš, Serbia
4. • Inexpensive, water insoluble dye which is
most commonly used for dyeing denim
fabric.
• So called as they contain sulphur linkage
within dye structure.
• Sulphur Black FF - Most important class
of sulphur dye.
Introduction:
04
5. 05
• Cheap
• Easy application.
• Saves up to 92 percent water, 30
percent energy and 87 percent
cotton waste.
• Wide range of black shades.
Introduction:
7. • 1873-Cachou de laval (saw dust, caustic soda and
Sulfur)
• 1893-Vidal Black (fusing para-phenylene diamine
with Na2S and Sulphur).
• In 1897-Immedial Black FF (2, 4-dinitro-4-
dihydroxy diphenylamine with Na-poly
sulphide).
• In 1896 Red Holliday (grey, brown and black
Sulfur dyes by the action of Sulfur, alkali
sulphides and many organic compounds.)
History:
07
9. • Water insoluble .
• Good light fastness with a rating 4 out 8
in blue scale.
• Excellent wash fastness with rating 3-4
out of 5 in grey scale.
• Good chemical resistance.
• Not applicable for protein fibers.
Characteristics:
09
12. • Breaks sulphur linkage within the molecules and
turns water insoluble dye into water soluble
leuco form.
• Dye-S-S-Dye + 2[H] Dye-SH + HS-Dye
• Reducing agents: Na2S, Na2S2O4, C2H4O2S
Reduction:
Water insoluble
sulphur dye
Water soluble
sulfur dye
(leuco form)
Reducing
agent
12
13. • Dyed fabric in presence of electrolyte.
• Soluble sulphur dye + Cotton Dyed cotton
Dyeing:
Leuco compound Soluble sulphur
dye in cotton
13
Electrolyte
14. • Thios groups are readily oxidized by the action of
atmospheric O2 or any other oxidizing agents and
reconverts water soluble leuco form of Sulphur dye
into previous water insoluble form.
• Dye-SH + HS-Dye + [O] Dye-S-S-Dye + H2O
• Oxidizing Agent: K2Cr2O7, NaBO3·nH2O,
Na2CO3·1.5H2O2, Na2O2, H₂O₂
Oxidation:
Water insoluble
sulphur dye
Water soluble
sulphur dye
(leuco form)
Oxidizing
agent
14
16. Causes:
• Excessive delay between lifting of the
material from the dye bath and washing off.
• Exposure of goods to air while dyeing.
• Too much common salts as exhausting agents.
• Insufficient Na2S in dye bath.
• Strong dye liquor in the dye bath.
Bronziness or Dullness of shades:
16
17. Remedies:
• Good washing and dilute solution of Na2S
(0.1%) at 300C.
• Treatment with boiling soap solution or a
strong Na2S solution.
• Treatment with a solution containing 10%
saponified palm oil at 600C.
Bronziness or Dullness of shades:
17
18. Causes:
• Gradual oxidation of Sulphur to H2SO4 on
storage.
• After treatment with copper salts
• Presence of iron as an impurity
• The method of oxidation in uncontrolled
manner
Sulphur black tendering:
18
19. Remedies:
• Treatment of dyed material with 1-3% of
K2Cr2O7 and 1-3% of CH3COOH at 60oC
temperature for 30 minutes followed by
through rinsing.
• Treatment with a little CH3COOH
• Treatment with 5 gm/liter soda ash after
dyeing followed by drying without rinsing.
Sulphur black tendering:
19
23. Treatment with a warm solution of Na2S
in the presence of polyvinyl pyrolodine
or NaOCl or bleaching powder (2-3
gm/liter of available chlorine) or KMnO4
or NaOCl in presence of NaOH.
Stripping:
23
25. 25
Zero Sulphur Product:
• Less toxic products.
• Safe for health.
• Can be used to dye fabric for upper
body products.
Electrochemical dyeing:
• Product savings.
• Less chemicals require.
• Unsurpassed chemical compatibility.
• Better fastness properties.
Innovation:
26. 25
Foam dyeing:
• Getting more attention worldwide.
• Eco-friendly.
• 99 percent water saving.
• 89 percent less chemical.
• 65 percent less energy.
Innovation:
28. 27
Sulphur dye is one of the most important
dye in our everyday dyeing application
specially an essential dye for our denim
industry. Also newer innovation is also
going on about this dye and hopefully will
be able to utilize this dye without less
environment pollution in future.
Conclusion: