Unit
- Cotton: A cellulose fiber prized for absorbency, breathability, and softness. Its staple length ranges from 1 to 2 inches, influencing yarn strength and fabric hand. Long-staple varieties like Egyptian cotton produce finer, more durable yarns.
- Linen: Derived from flax plant stems, linen fibers are two to three times stronger than cotton. They have a natural luster, low elasticity, and excellent moisture wicking. The fiber length (12-20 inches) requires wet spinning for smooth yarn.
- Wool: Protein fiber from sheep fleece, characterized by crimp, scales, and natural elasticity. The crimp frequency (per inch) determines fineness; merino wool has 20-30 crimps per inch, producing soft, springy yarns. Wool can absorb up to 30% moisture without feeling wet.
- Silk: Continuous filament produced by silkworms. The triangular cross-section gives silk a prismatic luster. It is the strongest natural fiber (4.8 g/denier) and has excellent drapability, but degrades under prolonged UV exposure.
- Bast fibers (hemp, jute, ramie): Extracted from plant stems through retting. Hemp fibers are 60% stronger than cotton and have natural antimicrobial properties. Jute is coarser, used for packaging and geotextiles. Ramie resists mildew and stains.
- Fiber classification by origin: Seed (cotton), bast (flax, hemp), leaf (sisal, abaca), animal (wool, silk, cashmere). Each category has distinct morphological features that affect processing, dye uptake, and end-use performance.
- Fiber fineness and length: Measured in micrometers (diameter) and millimeters (staple length). Finer fibers (e.g., 12-15 micron merino) yield softer fabrics. Longer staples produce stronger, smoother yarns with less pilling tendency.
- Moisture regain: The percentage of water a fiber can absorb at standard conditions (65% RH, 21°C). Cotton has 8.5%, wool 15-17%, silk 11%, polyester 0.4%. High regain fibers are more comfortable but shrink and wrinkle more.
- Cashmere: A fine animal fiber from the undercoat of cashmere goats, measuring 14 to 19 microns in diameter. Its extreme softness and lightweight insulating properties make it prized for luxury garments. However, cashmere has low tensile strength and requires blending with stronger fibers like wool or nylon to improve durability in woven or knitted fabrics.
- Fiber blending: Combining two or more fiber types in a yarn or fabric to achieve desired performance characteristics. Common blends include cotton-polyester for wrinkle resistance and durability, or wool-nylon for abrasion resistance in socks. The blend ratio affects cost, hand, moisture management, and care instructions, allowing designers to tailor fabrics to specific end uses.
- Fiber identification methods: Designers use burn tests, microscopic analysis, and chemical solubility to identify unknown fibers. For example, cotton burns with a paper-like odor and leaves ash, while wool smells like burning hair and forms a crushable bead. Microscopic cross-section views reveal unique shapes like silk’s triangular profile or cotton’s twisted ribbon structure, aiding quality control.
Design Principle
Principle: Fiber Selection Dictates Fabric Performance
Definition: The inherent properties of a fiber; tenacity, elongation, moisture management, and thermal retention; define the functional limits of the finished fabric. A designer must match fiber characteristics to the intended use environment.
Application: For activewear, choose polyester (low moisture regain, quick drying) blended with cotton (comfort). For luxury suiting, worsted wool (crimp gives resilience) with a small percentage of nylon to improve abrasion resistance. The fiber blend ratio directly controls cost, drape, and care requirements.
Quick Revision
- Natural fibers are categorized by origin: seed, bast, leaf, animal; each has unique mechanical and aesthetic properties.
- Fiber fineness (diameter) and staple length influence yarn count, strength, and fabric hand.
- Moisture regain affects dimensional stability, comfort, and dyeability; crucial for end-use selection.