Presentation on theme: "Materials for Textile Fibres properties and end uses."— Presentation transcript:
Materials for Textile Fibres properties and end uses
Abrasion Resistance Abrasion resistance is the (fibre) ability to resist to wear from rubbing which contributes to fabric durability. Garments made from fibres that possess both high breaking strength and abrasion resistance can be used for a long time before signs of physical wear. Nylon is used extensively in action outwear, such as ski jacket because it is very strong and resists abrasion extremely well. Acetate is often used for linings in coats and jackets because of its excellent drapability and low cost.
Absorbency Absorbency is the ability to take in moisture. It is usually expressed as a percent of moisture regain. Moisture regain is the amount of water a bone- dry fibre will absorb from the air under standard conditions (70%F, 65% relative humidity) Fibres able to absorb water easily are called hydrophilic fibres (e.g cotton and wool fibres plus rayon and acetate).
Absorbency Those fibres that have difficulty in absorbing water are called hydrophobic fibres (e.g polyester, nylon). The moisture regain for most man-made fibres are 4%. Glass fibre absorbs no water at all.
Effect of fibre absorbency Skin comfort: little absorption of perspiration results in a clammy feeling Static Build-up: Problems such as sparks occur with hydrophobic fibres because there is little moisture content to help dissipate the built-up charge on fibre surface. Dimensional Stability in water: Hydrophobic (polyester) fibres shrink less when washed than hydrophilic fibre (cotton). Wrinkle recovery fabric: Hydrophobic fibres usually possess better wrinkle recovery, particularly when laundered.
Cover Cover is the ability to occupy an area. A thick fibre or one with a crimp or curl will give the fabric better cover than a thin, straight fibre. The fabric will also be warmer, look and feel more substantial and require fewer fibres to make it. Wool is a widely used fiber for blankets and winter wear because its crimp gives excellent cover, resulting in large amount of air being trapped in the fabric. The “dead air” spaces provide insulation against the cold.
Elasticity Elasticity is the ability to increase in length when under tension (elongation) and then return to the original length when released (recovery). Fibers that can elongate at least 100% are called elastomeric fibres. Spandex and rubber are two fibres that are in this category.
Environmental Conditions The effect of environmental conditions on fibres vary. How fibres react and ultimately, how the fabrics react to certain exposure or storage is important. Wool garments (animal fibres) should be mothproofed when stored. Nylon and silk show strength loss when extended exposure to sunlight. Therefore, they normally are not used for curtains and drapes. Cotton has poor resistance to mildew and should not be allowed to remain wet for long periods of time.
Flexibility Flexibility is the ability of a fiber to bend easily as well as repeatedly without breaking. A flexible fibre such as acetate can be made into a highly drapable fabric and garment (hangs with graceful folds). A rigid fibre like glass usually makes a fabric that is relatively stiff. Usually the thinner the fiber, the better its drapability.
Pilling Pilling is the formation of groups of short or broken fibers on the surface of a fabric which are tangled together in the shape of a tiny ball called a pill. These pills are formed when the ends of a fiber break from the fabric surface. Pilling is not a desirable property since it makes fabrics look worn and unsightly.
Pilling Hydrophobic (polyester) fibers tend to pill much more than hydrophilic fibres since the hydrophobic fibers have a greater attraction for each other and do not fall off the fabric surface. Pills are not found on the collar of a 100% cotton shirt but are quite common after a period of wear on similar shirt made of cotton and polyester. Wool although hydrophilic, pills because of its scaly surface. The fibers snag each other, tangle, and form a pill. Strong fiber tends to hold pills to the fabric surface. Because weak fibres break, pills fall off easily and pilling is not noticeable.