Chapter 2

Hand

way a fiber, yarn, or fabric feels when handled hand of a fiber is affected by its shape, surface, and configuration soft, crips, dry, silky, stiff, board, or harsh

Fibrillation

when stiff fibers splinter along their length; form unsightly splinters on the surface of the fabric ex: lyocell

Flameproof Fibers

will not burn

How does fiber absorbency affect the properties of a textile?

Absorbency affects: skin comfort, static build-up, dimensional stability in water, stain removal, water repellency, and wrinkle recovery.

Why can cotton be produced only in staple form but manufactured fiber such as polyester can be produced in both filament and staple form?

Cotton only grows as a staple, but polyester can be produced in long filaments and kept as filaments, or be cut into short staples.

What is crimp and how does it affect the properties of a textile?

Crimp is the bends and twists along the length of a fiber. It increases resiliency, bulk, warmth, elongation, absorbency, and skin comfort. Makes the hand harsher and luster is reduced as crimp increase. Allows the fiber to stand off the skin so fabric will not cling to the wearer's skin. Also helps make the fiber able to withstand being bent back on itself many times without breaking.

Spinnerette

Device with tiny holes that produces filament fibers; holes can be made in different shapes to form the cross-sectional shape of each fiber.

What is pilling? Why is it more apparent on some fibers than on others?

Pilling is the formation of groups of short or broken fibers on the surface of a fabric that tare tangled together into tiny balls (pills). More apparent on hydrophobic fibers because their fibers have greater electrical static attraction for each other ran do not fall off the fabric surface. Wool also pills because it has a scaly surface.

What differences in appearance and hand would you expect between two identical fibers, one with round fibers and the other with triangular fibers?

Round Fibers = bulkier fabric, possibly smoother, more slippery hand Triangular Fibers = more luster

Tow

Thousands of filaments grouped to gather forming a thick rope adding crimp to a fiber by heat setting the fibers in a crimped configuration

Which fiber would be more suitable for athletic wear; one that wicks or one that absorbs moisture? Why?

Wicking fibers are more suitable for athletic wear because it wicks sweat along the fiber surface to the outer surface so it can evaporate and improve comfort, versus a fiber that absorbs moisture would hold the sweat and feel wet.

State the fiber property that most affects the indicted condition: a. pilling propensity b. producing permanent pleats c. improving insulation d. resistance to wear from rubbing e. static buildup f. determination of hand g. excessive wrinkling h. good drawability i. preventing clammy feeling on a hot day j. resisting pulling force k. degree of luster

a. pilling = hydrophobic & strength & static electricity b. pleats = resiliency & thermoplasticity c. improving insulation = crimp/longitudinal configuration d. resistance to wear from rubbing = abrasion resistance e. static buildup = hydrophobic fibers f. determination of hand = fiber shapes, surfaces, and configuration g. excessive wrinkling = resiliency & absorbency & thin fiber diameter h. good drawability = strength &stretch i. preventing clammy feeling on a hot day = wicking & absorbency j. resisting pulling force = strength & elasticity k. degree of luster = fiber shape/surfaces

What changes in the spinneret would have to be made for the following to occur: a. to produce thicker filament fiber b. to increase the number of filaments being produced c. to change the cross-sectional shape of the fiber being produced

a. to produce thicker filament fiber = bigger holes b. to increase the number of filaments being produced = increase number of holes c. to change the cross-sectional shape of the fiber being produced = change shape of holes

Wicking

ability of a fiber to transfer moisture form one section to another; usually along the fiber surface, but is may also fast through e fiber when a liquid is absorbed by the fiber smooth surface fiber reduced wicking action

Flammability

ability to ignite or burn (flammable, flame resistant, or flame proof)

Elasticity

ability to increase in length when under tension (elongation) and then return to the original length when released (recovery) Stretch and recovery when tension is placed on the fiber or fabric makes for a more comfortable garment and causes less seam stress also tends to increase breaking strength of the fabric complete recovery helps prevent bagginess from occurring at elbows/knees and it prevents the garment from becoming loose fitting ex: spandex, elastrell-p, lastrol, and rubber = elastomeric

Cover

ability to occupy an area a thick fiber or one with crime p or curl gives fabric better cover than a thin, straight fiber; the fabric is warm and looks/feels substantial, but requires fewer fibers to be made

Abrasion Resistance

ability to resist wear for rubbing that contributes to fabric durability garments with high breaking strength and abrasion resistance can be worn often and for a long period of time before signs of physical wear appear

Absorbency

ability to take in moisture expressed as a percentage of moisture regain

Thermoplastic

able to be melted these fibers soften when heat is applied and may melt to a liquid state when higher that is applied

Hygroscopic

absorb moisture worth feeling damp ex: silk and wool

Hydrophilic

absorbs water easily ex: cotton and acetate all natural anima and vegetable fibers are, as are rayon, lyocell, and acetate

Crimp

bends and twists along the length of a fiber greater crimp increases resiliency, bulk, warmth, elongation, absorbency, and skin comfort, but hand becomes harsher and luster is reduced as crimp increases allow the fiber to stand off the skin so fabric will not cling to the wearer's kin and to produce a cold sensation when worn also helps make the fiber able to withstand being bent back on itself many times without breaking

Resiliency

capability of a material to spring back to shape after being creased, twisted, or distorted connected with wrinkle recovery ex: polyester (outstanding); cotton (poor)

Flexibility

capability of the fiber to bend easy and repeatedly without breaking ex: acetate (good flex) vs. glass (bad flex)

Filament Fibers

fibers whose lengths are too long to be measured in inches. ex: silk (only natural fiber that is found in filament form)--1600 yrs long on average

Dry Spinning

fiber solution, mixed with a solvent, is forced through the spinnerette into warm air, the warm air helps evaporate the solvent, and the liquid stream then hardens. ex: acetate and modacrylic

Strength

fiber's ability to withstand stress force needed to break the fiber = tenacity and is expressed ing rams per denier or grams per fiber weight strong fibers = glass, nylon, and polyester weak = acetate and acrylic

Epitropic Fibers

fibers that conduct electricity have no static problems eliminate shocks, fabric cling, and dust attraction esp. important in hospitals, computer work areas, etc.

Hydrophobic

fibers that have difficulty absorbing water and are only able to absorb small amounts ex: glass all manufactured fibers (except rayon, lyocell, and acetate)

Stable Fibers

fibers whose lengths are measured in inches ex: cotton (0.5-2.5 in. long)

Pilling

formation of groups of short or broken fibers on the surface of a fabric that are tangled together in the shape of a tiny ball (called pills) formed when ends of a fiber break form the fabric surface, usually from wear make fabrics look worn and unsightly and feel less comfortable

Static Electricity

frictional electric charge caused by the rubbing together of tow dissimilar materials effects = clothing's clinging to the wearer or lint from electric charge being retained and built up on the surface hydrophobic = prone to static (except glass, no static charge can build up on the surface of glass)

Flame-Resistant Fibers

have a relatively high ignition temperature and slow rate of burning, may also be self-extinguishing

Luster

light reflected form a surface increased light reflection from smoother surface, less crimp, flatter cross-sectional shape, and longer fiber length

Specific Gravity

ratio of the mass of the fiber to an equal volume of water at 4 degrees C lightweight fiber enables a fabric to be warm without being heavy ex: acrylic

Flammable Fibers

relatively easy to ignite and sustain combustion

Melt Spinning

solid material is melted to form a liquid solution that is forced through the spinneret and into cool air, where the liquid fiber streams harden into continuous filament. ex: glass, nylon, polyester, and olefin fibers

Wet Spinning

solution is forced through the spinneret and then into liquid solution in which the fiber solution streams harden tiny continuous filaments. ex: acrylic & viscose ray on fibers

Natural Fiber

those fibers found in nature--obtained from plants or animals

Manufactured Fibers

those fibers man-made from chemical solutions that are forced through tiny holes (spinneret) to form filaments--designed to resolve particular problems and answer specific needs