Question

From the following, highest moisture regain can be seen in

• A. Linen
• B. Jute
• C. Silk
• D. Acetate

Hint:

• Moisture regain is the weight of water in a material expressed as a percentage of the oven-dry weight of the material.
• Natural fibers (especially cellulosic like cotton, linen, jute, and protein like wool, silk) generally have higher moisture regain than synthetic fibers.
• Jute is particularly hygroscopic. Wool has very high regain as well.
• Among the options: Jute>Silk $\approx$ Linen>Acetate.

Answer 1

The Correct Option is B

To determine which fiber—Linen, Jute, Silk, or Acetate—has the highest moisture regain, let’s break down the concept and solution in a detail. 

What is Moisture Regain?

Moisture regain is a measure of how much water a textile fiber can absorb from the air under standard conditions (typically 65% relative humidity and 20°C). It’s expressed as a percentage, calculated using the formula:

Moisture Regain (%) = (Weight of absorbed water / Dry weight of the fiber) × 100

For example, if a dry fiber weighs 100 grams and absorbs 12 grams of water, its moisture regain is 12%. This property is important in textiles because it affects comfort, dyeing, and processing. Fibers with higher moisture regain feel more comfortable in clothing (as they absorb sweat) and are easier to dye but may be less durable in wet conditions.

Let’s examine each fiber listed in the question, focusing on its composition and how it influences moisture regain:

1. Linen

• Type: Natural, plant-based (cellulosic) fiber from the flax plant.
• Structure: Linen is made of cellulose, a natural polymer that loves water (hydrophilic). Its molecular structure has many hydroxyl (-OH) groups that attract and hold water molecules.
• Moisture Regain: Approximately 12%. This means 100 grams of dry linen can absorb about 12 grams of water.
• Why?: The cellulose structure allows linen to absorb moisture effectively, making it breathable and comfortable for clothing like summer shirts.

2. Jute

• Type: Natural, plant-based (cellulosic) fiber from the jute plant.
• Structure: Like linen, jute is primarily cellulose but has a coarser and more porous structure. It also contains some lignin (a less hydrophilic component), but its cellulose content dominates.
• Moisture Regain: Approximately 13.7%. This means 100 grams of dry jute can absorb about 13.7 grams of water.
• Why?: Jute’s high cellulose content and porous structure allow it to hold more water than linen, making it suitable for applications like sacks or burlap, though it’s less common in clothing.

3. Silk

• Type: Natural, animal-based (protein) fiber produced by silkworms.
• Structure: Silk is made of proteins (fibroin) with a smoother, less porous structure than cellulosic fibers. It has some ability to absorb water due to its protein chains, but it’s less hydrophilic than cellulose.
• Moisture Regain: Approximately 11%. So, 100 grams of dry silk can absorb about 11 grams of water.
• Why?: Silk absorbs moisture reasonably well, which contributes to its luxurious feel and comfort in clothing, but its protein structure limits its water-holding capacity compared to cellulosic fibers.

4. Acetate

• Type: Semi-synthetic fiber made from cellulose (from wood pulp or cotton) that is chemically modified into cellulose acetate.
• Structure: The chemical modification (acetylation) replaces some of the hydroxyl groups in cellulose with acetate groups, making it less hydrophilic (less attracted to water).
• Moisture Regain: Approximately 6.5%. This means 100 grams of dry acetate can absorb about 6.5 grams of water.
• Why?: The chemical changes reduce its ability to bond with water, making acetate less absorbent than natural cellulosic fibers. It’s often used in linings or garments where low moisture absorption is desired.

Why Does Moisture Regain Vary?

The ability of a fiber to absorb water depends on its chemical composition and physical structure:

• Cellulosic fibers (like linen and jute) have many hydroxyl groups that form hydrogen bonds with water, leading to higher moisture regain.
• Protein fibers (like silk) have some water-attracting groups but fewer than cellulose, so their moisture regain is moderate.
• Semi-synthetic fibers (like acetate) have chemically altered structures that reduce water-attracting sites, resulting in lower moisture regain.

Comparing the Fibers

Now, let’s compare the moisture regain values of the four fibers based on standard textile data:

• Linen: ~12%
• Jute: ~13.7%
• Silk: ~11%
• Acetate: ~6.5%

To find the fiber with the highest moisture regain, we look for the largest percentage:

• 6.5% (Acetate) is the lowest.
• 11% (Silk) is higher than acetate but lower than the others.
• 12% (Linen) is higher than silk but not the highest.
• 13.7% (Jute) is the highest value.

Thus, Jute has the highest moisture regain.

Why Jute?

Jute’s slightly higher moisture regain compared to linen can be attributed to its coarser, more porous structure, which allows it to hold more water despite having a similar cellulose-based composition. This makes jute particularly absorbent, though its rough texture makes it less common in clothing compared to linen or silk.

Final Answer

Among Linen, Jute, Silk, and Acetate, Jute has the highest moisture regain at approximately 13.7%.