Question

A method of dyeing fabric blends:

• A. \( \text{Union dyeing} \)
• B. \( \text{Top dyeing} \)
• C. \( \text{Solution dyeing} \)
• D. \( \text{Direct dyeing} \)

Hint:

To remember "Union" dyeing, think of the fibers coming together in "union" to show one single color. If you wanted the fibers to show different colors (a heather effect), that would be called "Cross dyeing."

Answer 1

The Correct Option is A

Concept: Blended fabrics consist of two or more different types of fibers (e.g., Polyester and Cotton). Because each fiber has different chemical affinities, achieving a uniform color across the entire fabric requires specialized dyeing strategies.

Step 1: Identify the method for uniform color in blends.
Union dyeing is a process where a fabric containing two or more different fibers is dyed a single, uniform color. This is achieved by using a dye bath that contains different classes of dyes, each specific to one of the fibers in the blend, but matched to the same shade.

Step 2: Evaluate other options.

• Top dyeing: Dyeing wool fibers after they have been combed into "tops" but before spinning.
• Solution dyeing: Adding pigment to the liquid polymer before fiber extrusion.
• Direct dyeing: A method used primarily for 100% cellulosic fabrics.