Sizing in textile industry
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The document discusses the process of textile sizing, which involves applying an adhesive coating to yarn to enhance its properties, such as strength and smoothness. It details various sizing materials, their functions, types, and the advantages and disadvantages of sizing. Key ingredients include gums, lubricants, antiseptics, and agents for improved wetting and foaming control.
Sizing in textile industry
- 1. Study on Textile Sizing Presented by: Md: Fahimuzzaman Department of Textile Engineering Mawlana Bhashani Science and Technology University
- 2. Sizing • The process of applying a protective adhesive coating upon the yarns surface is called sizing. • Starch, gelatine, oil, wax, and manufactured polymers such as polyvinyl alcohol, polystyrene, polyacrylic acid, and polyacetates are employed as a size materials Starch Gelatine
- 3. Objects of Sizing • To protect the yarn from abrasion • To improve the breaking strength of the yarn • To increase smoothness of yarn • To increase yarn elasticity • To decrease hairiness • To decrease the generation of static electricity
- 4. Types of Sizing • Pure sizing: when the size pick up % is about 3 – 10 % • Light sizing: when the size pick up % is about 11 -16% • Medium sizing: when the size pick up % is about 17 – 40 % • Heavy sizing: when the size pick up % is above 40 %
- 5. Size Ingredients & Their Functions 1. Gums: There are two types of gum: Natural: Wheat flour, corn flour. Synthetic: Polyvinyl alcohol, Carboximethyl cellulose, Polyacryloamide. Functions: Coat the warp yarn with a film. Impart smoothness. Blind the protruding fibres to the yarn surface. Increase elasticity.
- 6. Size Ingredients & Their Functions 2. Lubricants or Softeners Vegetable & animal fats, Japan wax, tallow, cotton seed & castor oils, stearine, glycerin, soap, TRO etc. Function: To give a softer feel to the sized yarn. To reduce stickiness of yarn. To smoothen the yarn. 3. Antiseptic or Anti Mildew Agent: Phenol, boric acid, carboxylic acid, zinc chloride, sodium silicofluoride, cresol etc. The quantity used is very low 0.1 to 2%. Function: To prevent the growth of mildew. To prevent spoiling of the size mix during storing it for long time. To help to store the sized yarn.
- 7. Size Ingredients & Their Functions 4. Wetting Agent: Sulphanol A, soap, avirol, alizarin oil etc. The amount of wetting agents introduced into the size should not exceed 0.1 to 0.15 gm/ltr. Function: To improve the size wet ability. Improve the penetration of the size between the fibres. Uniform distribution of the sizing solution on the yarn surface is obtained. 5. Antifoaming Agent: Silicones, stearine-paraffin emulsions, benzene, pyridine. The antifoaming agents in amounts of 0.05 to 0.1 gm/ltr are stirred in a small quantity of warm water. Function: To prevent formation of foam.
- 8. Size Ingredients & Their Functions 6. Tinting Agent: Blue is used as tinting agent. Function: To increase the brightness & remove yellowish color of yarn. To prevent dusting off. To form a particular shade. 7. Weighting Agent: The most commonly used substances are soluble inorganic powders such as china clay, talc, barium or calcium sulfate. Function: To give additional weights to the goods. To prevent opening of cloth.
- 9. Properties of sized yarn: Higher elasticity Higher yarn strength Lower flexibility Lower extension or elongation Lower frictional resistance Increased smoothness Less weakness Insensible to over drying Less hairiness
- 10. Disadvantages of Sizing Cost of land and machine is high Requires lot of labors Requires utility like gas, electricity etc and their cost is high Cost of ingredients The process is long and it takes time There is a risk of degradation of yarn The yarn diameter is increased Requires robust loom