Textile sizing The process of applying a protective adhesive coating upon the surface of the yarns is called sizing. Starch, gelatine, oil, wax, and manufactured polymers such as polyvinyl alcohol, polystyrene, polyacrylic acid, and polyacetates are employed as size materials 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

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