TopicsImportance of soft water for

better quality product

Prepared by

Name:Suman Das

Id :151-23-176

Dept of Textile

Daffodil International University (permanent campus)

29 Batch

Welcome To Our

Presentation

Outline Introduction

Key sources of water

Types of water

Water consumption in textile wet processing industry

Problem create by hard water

Standard quality of soft water for dye house

Water resources are sources of water that are useful .Uses of water include agricultural ,industrial, household, recreational and environmental activities. The majority of human uses require fresh water.

98 % of the water on the Earth is salt water and only three percent is fresh water; slightly over two thirds of this is frozen . The remaining unfrozen freshwater is found mainly as groundwater.Water Is the life –line of textile industry

Introduction

Key sources of water

Surface water Ground waterFrozen waterDesalination

Types of water Hard Water: Hardness is defined as the the presence of sulphates, carbonets and bi-carbonets of calcium, magnesium and ferrous salts make hard water.

Soft water:Water containing little or no dissolved salts of calcium or magnesium, especially water containing less than about  85 P.P.M(parts per million) of calcium carbonate.

Types of water hardness:Temporary hardness: The presence of calcium(Ca),magnesium(Mg) and Iron(Fe) makes the water temporary hard.

Temporary hardness can be removed easily by boiling the water.

Permanent hardness: When water contains soluble salts of calcium and magnesium such as their sulphates and chlorides.

Permanent hardness can’t be removed by boiling.

Water Consumption in Textile Processing Industry

Water is used widely throughout textile processing operations. Almost all dyes, specialty chemicals, and finishing chemicals are applied to textile substrates from water baths. In addition, most fabric preparation steps, including desizingscouring Bleaching and mercerizing  The amount of water used varies widely in the industry, depending on specific processes operated at the mill, equipment used.

Hard water can create so many problems during wet processing from desizing to finishing in textile mills. Since every process is related to the next process, so all  processes should be done exactly to get best result or best quality product. To do it first we have to know what problems hard water can create in different stage of wet processing.

In Boiler: If hard water is used in boiler, then a layer is formed on the inner surface of the vessel. This layer is very hard just like as stone which is not removed without hammer or chesser or tessel. This is called scale. In boiler, temporary hard water produce CaCO3 & Mg(OH)2, the combination of CaCO3 & Mg(OH)2 is called scale

Desizing: Hard water de-active enzymes & insolubilize size materials such as starch, PVA etc.

Problem create by hard water

Scouring: Hard react with soap during scouring. Soap is the Na & K salt of higher fatty acid (C17H35COONa). The Ca & Mg salt of hard water react with soap and produce insoluble organic salts which becomes the wastage of soap.

CaSO4 + 2 C17H35COONa --> (C17H35COO)2Ca + Na2SO4                                                     Insoluble organic salt

Bleaching: Hard water decompose bleach bath.H2O2 --> H2O + [O]

Mercerizing: It forms insoluble metal acid, reduce absorbency and luster.

Problem create by hard water

Dyeing: Ca2+ and Mg2+ ions of hard water react with dye molecules and precipitated the dye. As a result dyestuff are spoilt. Hence, uneven shade (depth of dyeing) of color is produced.

Printing: It break the emulsion, change it’s thickness and efficiency and it is also harmful for thickener. Hard water cause problems in printing process like dyeing.

Problem create by hard water

Uneven shade

From above, we saw that hard water causes problems in every process of wet processing. So, we have to use such water that is suitable for wet processing and don’t create any problem. Ideal quality of feed water for textile industry is :

Finishing: Hard water interfere with catalysts, cause resins and other additives to become non reactive, break emulsion and deactives soap

Problem create by hard water

•pH should be in the range of 7 – 8.•Water should be odorless & colorless.

•Water hardness : maximum 5° dH.•Solid content : < 50 mg/L.•Dissolved solids : < 1 mg/L.•Inorganic salts : < 500 mg/L.•Organic salts : < 20 mg/L.•Iron (Fe) : < 0.1 mg/L.•Mn : < 0.02 mg/L.•Cu : < 0.005 mg/L.•Nitrate : < 50 mg/L.•Nitrite : < 5 mg/L.

Standard quality of soft water for dye house

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