Scouring Process Objectives and Factors in Textile

Introduction

Scouring is the process of removing all the natural and added impurities like oil, wax, fat, and so on to produce hydrophilic and clean textile material. It is an important step in the wet processing process.

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Objectives of Scouring

1. To increase the fabric's hydrophilicity
2. To remove as many impurities as possible, such as oils, waxes, gum, and husks.
3. Increasing the absorbency of fabric or textile materials without causing physical or chemical damage
4. To make a clean material by adding alkali
5. Removing natural color and preparing the fabric for the next process

The Change Occurring in Cotton Fibers During Scouring

1. Soaps are created by combining saponifiable oils and free fatty acids
2. Pectins and pectoses are broken down into pectic acid-soluble salts
3. Proteins are broken down into soluble amino acids or ammonia
4. Minerals are mostly dissolved
5. Saponifiable matters emulsify non-saponifiable oils
6. The soap removes additional dirt and dissolves it in suspension
7. Residual sizing materials are degraded into soluble byproducts

Scouring Process Depending Factors

1. Type of cotton
2. Color of cotton
3. Cleanliness of cotton
4. Twist and count of the yarn
5. Construction of the fabric

Chemicals Used in Scouring Process

1. Caustic Soda → Neutralize acidic material, saponify glycerides (waxes and oils)
2. Surfactants → Reduce surface tension while decreasing interfacial tension
3. Detergents → Oil, fats, and waxes are emulsified, and oil-borne stains are removed
4. Chelating Agent → Deactivate metal ions
5. Sodium Silicate → Lignin penetration and degradation
6. Builder → Increase the effectiveness of detergents
7. Solvent → Dissolve oily materials to assist in emulsification

Forms of Scouring

Yarn scouring

1. Hank form
2. Package form
3. Continuous sheet form

Fabric scouring

1. Open width form (Jigger and Pad batch machine)
2. Rope form (Kier and winch machine)

Scouring Methods of Cotton

Generally, there are two principal methods of cotton scouring

1. Kier boiling process (Discontinuous)
2. Scouring in J box (Continuous)

Scoured Cotton Sample