Dyeing - Total Textile Process at a Glance

Water ,Hardness,Surfectents , Detergent Total Textile Process at a Glance The course comprised – 1. Applied chemistry: Water & water treatment, surfactants 2. Dyeing: Dyeing theory & mechanism, Mordant dyes, Pigments, Mineral colors 3. Printing: Special types of thickener, Screen printing technology 4. Finishing: Softener, Special types of finishing Don’t be a serious student Be a smart & innovative student Water and Water Treatment Water can be classified as - 1. Rain water. 2. Surface water stock in ocean, rivers or lakes. 3. Subsoil water, which has percolated a small distance into the ground. 4. Deep well waters which have usually percolated through several layer. General characteristics of water Water shows maximum density at 4ºC, 1 gm/cc. its specific gravity is also 1. Freezing temperature 0ºC and boiling temperature is 100ºC. Properties of textile supply water Minimum Standard Acceptable limits Color Colorless Smell Odorless pH value Neutral (pH 7- 8) Water hardness < 25 ppm of Ca CO3 Acidity/Alkalinity < 100 mg/l as Ca CO3 Dissolved solids < 150 mg/l Filterable solids < 50 mg/l Suspended solids < 1 mg/l Turbidity < 5 mg/l Dissolved oxygen Not permit Carbon dioxide < 50 mg/l Iron (Fe) < 0.1 mg/l Copper (Cu) <0.005 mg/l Manganese (Mn) < 0.02 mg/l Lead or heavy metals < 0.01 mg/l Alluminium (Al) < 0.25 mg/l Silica < 3.0 mg/l Sulphate < 250 mg/l Sulphide < 1 mg/l Chloride < 250 mg/l Chlorine < 0.1 mg/l Nitrite (NO2 ) < 5 mg/l Nitrate (NO3 ) < 50 mg/l Ammonia < 0.5 mg/l Oil, grease, fat, soap < 1 mg/l Total solids < 500 mg/l Water Hardness Generally soaps create foam in water, but in present of some materials the foam creation is reduced and need more soap for producing foam, and this condition of water is called water hardness. Reasons of water hardness 1. Temporary hardness: Ca(HCO3)2, Mg(HCO3)2, Fe(HCO3)2 2. Permanent hardness: CaCl2, CaSO4, Ca(NO3)2, MgCl2, MgSO4, Mg(NO3)2 [...]... direct reading digital meter or strip  In laboratory it is usually determined by titration with a standardized solution (e.g Na-EDTA) – for mechanism see my book Estimation of total (permanent & temporary) hardness of supply water (by di-sodium salt of EDTA)  Basic principle: - Titration of sample water against standards (0.01M) EDTA solution  Preparation of 0.01M or 0.02N EDTA solution: Molecular weight... tone; then calculate the total hardness in terms of ppm of CaCO3 Table: Experimental data Calculation: Total hardness = Volume of 0.01M EDTA solution in ml × 1000 ppm of CaCO3 Volume of sample water in ml Determination of temporary hardness of supply water  Basic principle: - This can be estimated by titration of sample water against standard solution of hydrochloric acid ( 0.05N... color of indicator change orange to red  Table I: Experimental data for reading a  Table II: Experimental data for reading ‘b’  Calculation: Temporary hardness = 50(b -a) × 0.05 × 1000 - ppm (in terms of CaCO3) 100 Determination of permanent hardness of supply water (by disodium salt of EDTA)  Preparation of 0.01M or 0.02N EDTA solution: Molecular weight of disodium salt of EDTA (CH2COOH)2... Procedure: - Add 1cc or 2 – 3 drop [from the solution of (0.1 gm solid methyl orange + 100cc distilled water)] methyl orange indicator to 100ml of fresh distilled water & titrate against 0.05N HCl Let the titration reading be a ml - Now titrate 100 ml of the sample water against 0.05N HCl using the same indicator (methylorange) Let the titration reading ‘b’ ml  Observation: - Reading should be taken... does the water hardness affect the textile processing? Desizing Scouring Bleaching Mercerizing Deactivate enzymes and makes it insolubilize some size materials like starch and PVA Combine with soap, precipitate metalorganic acids Produce yellowing of offwhite shades, reduce cleaning efficiency, and water absorption Decompose bleach baths Form insoluble metal oxides, reduce absorbency and luster Dyeing. .. NH4Cl + distilled water to make 250ml solution to give a pH of 10  Procedure: - Add 1ml of buffer solution (NH4OH+NH4Cl) to 100ml of the original water sample Add 3-4 drops of Eriochrome Black T indicator (0.2g dye in 15ml of triethanol amine + 5ml of ethanol)/ 1tablet (making powder) total hardness indicator - Titrate against 0.01M prepared EDTA solutions in burette until the color charges from wine... dyes changing their shades, insoubilize dyes, cause tippy dyeing, reduce dye diffusion and hence results in poor washing and rubbing fastness Printing Break emulsions, change thickener efficiency and viscosity, and those problems indicated for dyeing Finishing Interfere with catalysts, cause resins and other additives to become nonreactive, break emulsions and deactivate soaps Estimation of water hardness... using hard water –  Precipitation of soaps;  Redeposition of dirt and insoluble soaps on the fabric being washed – this can cause yellowing and lead to unlevel dyeing and poor handle;  Precipitation of some dyes as calcium or magnesium salts;  Scale formation on equipments and in boilers and pipelines;  Reduction of the activity of the enzymes used in desizing;  Decrease solubility of sizing agents;...Hardness Scales     German degree French degree American degree British degree Definition of Different Hardness 1 1º H (German) Hardness: 10 mg CaO in 1 litre of water 2 1º H (French) Hardness: 10 mg CaCO3 in 1 litre of water 3 1º H (English) Hardness: 10 mg CaCO3 in 0.7 litre of water 4 1º H (American) Hardness: 1 mg CaCO3 in 1 litre of water Other scales for expressing water hardness ... substances per 100,000 parts of water is known pp/100,000 Grains per imperial gallon (gpg imp): The number of grains of substances per 1 British imperial gallon of water (1 imperial gallon of water weighs 10.0 pound) is known gpg imp Relation of different scales - 1 ppm = 1.0 mg/l = 0.1 pp/100,000 = 0.0583 gpg (U.S.) = 0.07 gpg imp Conversion factor of different water hardness scale Scale Hardness USA . student Be a smart & innovative student Water and Water Treatment Water can be classified as - 1. Rain water. 2. Surface water stock in ocean, rivers or lakes. 3. Subsoil water, which has percolated. Water ,Hardness,Surfectents , Detergent Total Textile Process at a Glance The course comprised – 1. Applied chemistry: Water & water treatment, surfactants 2. Dyeing: Dyeing theory &. mg/l Total solids < 500 mg/l Water Hardness Generally soaps create foam in water, but in present of some materials the foam creation is reduced and need more soap for producing foam, and