Question

Objectives of scouring of cotton. 
A. To remove natural fatty matter from textiles. 
B. To remove added fatty matter from textiles. 
C. To remove pectins from textiles. 
D. To remove coloring matter from textiles. 

• A. A, B and D only
• B. A and C only
• C. A, B, C and D
• D. C and D only"

Hint:

Remember the specific roles of pre-treatments: - Singeing: Removes surface fuzz. - Desizing: Removes added size. - Scouring: Removes natural waxes and pectins for absorbency. - Bleaching: Removes natural color for whiteness.

Answer 1

The Correct Option is B

Step 1: Define the purpose of scouring. Scouring is a cleaning process that uses an alkaline solution to remove natural, non-cellulosic impurities from cotton fibers. The primary goal is to make the fiber highly absorbent for subsequent wet processing like bleaching and dyeing.

Step 2: Analyze the listed objectives.
- A. To remove natural fatty matter from textiles: Cotton contains natural waxes and fats that make it hydrophobic (water-repellent). Scouring saponifies these fats, making them soluble in water so they can be washed away. This is a primary objective.
- B. To remove added fatty matter from textiles: Added matter like spinning oils or knitting oils are typically removed in a separate, prior process called "desizing" or a specific pre-washing, not the main scouring process which targets natural impurities.
- C. To remove pectins from textiles: Pectins are natural gummy substances in cotton that bind other impurities to the fiber. Scouring degrades and removes them. This is a primary objective.
- D. To remove coloring matter from textiles: Scouring removes some natural coloring matter, but the primary process for decolorizing cotton is bleaching. Therefore, removing color is not a main objective of scouring itself.

Step 3: Conclude based on the primary objectives. The main goals of scouring are to remove natural waxes/fats (A) and pectins (C) to improve absorbency. Therefore, A and C only is the correct choice.