Ch. 3

Tenacity

(tensile strength) ability of a textile to withstand a pulling force; measured by clamping both ends of the fabric and pulling on each end with force, measuring the force needed for breakage or rupture

Visual Inspection Points

1. Length of Fiber- untwist the yarn to determine the fiber length 2. Luster of Lack of Luster 3. Body, Texture, Hand

Parts of a Natural Fiber

1. The Cuticle of Skin- an outer covering 2. An Inner Area 3. A Central Core that may be hallow

Cellulose

Fibers based on plants; tend to be heavy, absorbent, heat resistant, prone to wrinkling, damaged by acids and mildew, and highly flammable

Morphology

Physical Structure

Fiber Classification System

TABLE 3.1

Natural Fibers

Those that are in fiber form as they grow or develop and come from animal, plant, or mineral sources

Denier Per Filament (dpf)

a way of identifying fiber size often used when describing or specifying yarns, calculated by dividing the yarn size by the number of filaments (ex: 40 denier yarn/20 filaments= 2dpf); most apparel is 1-7, carpet is 15-24, textiles are less than 1 to 1000 plus

Cohesiveness

ability of fibers to cling together during spinning

Shrinkage Resistance

ability of a fabric to retain its original dimensions throughout care; related to the fabrics reaction to moisture or heat

Dimensional Ability

ability of a fabric to retain its original size and shape through use and care, which is desirable; include the properties of shrinkage resistance and elastic recovery

Cover

ability of a fiber to conceal a product

Absorbency

ability of a fiber to take up moisture from the body or from the environment; measured as moisture regain where the moisture in the material is expressed as a percentage of the weight of the moisture-free material; related to static build-up

Wicking

ability of a fiber to transfer moisture along its surface; fibers that wick well are not ver absorbent; moisture is transported along the surface rather than being absorbed

Translucence

ability of a textile to allow light to pass through it; fibers that are (like nylon or polyester) must be altered by additives during production or by changing their cross section to provide cover

Heat/Thermal Retention

ability of a textile to hold heat; affected by fiber yarn, and fabric structure and layering of fabrics

Elasticity (Elastic Recovery)

ability of a textile to return to its original dimension or shape after elongation; measured as the percentage of return to original length; varies with the amount of elongation and with the length of time the fabric is stretched

Resiliency

ability of a textile to return to its original shape after bending, twisting, or crushing

Abrasion Resistance

ability of a textile to withstand the rubbing it gets during use

Strenth

ability to resist stress

Loft (Compression Resiliency)

ability to spring back to the original thickness after being compressed

Electrical Conductivity

ability to transfer electrical charges; do not build up static charge readily and do not attract lint or create problems with static cling

Heat Conductivity

ability to transfer heat through a fabric

Light (Sunlight Reistance)

ability to withstand degredation from natural or aritfical light

Hygroscopic

absorb moisture without feeling wet

Stretching (Drawing)

casuses the random, unoriented polymer chains in manufactured fibers to slide and become more parallel to each other and to the longitudinal axis of the fiber; reduced fiber diameter and compacts the molecules

Alkalis (Bases)

compounds that remove hydrogen ions from acids and combine with the acid in a chemical reaction

Acids

compounds that yield hydrogen ions to alkalis in chemical reactions

Cradle to Cradle

concept that is environmentaly intelligent framework that examines the overall impact of the production, use, care, disposal, and recycle potential of products, including textile products, from economic, industrial, and social perspectives

Creep

delayed or gradual recovery from elongation

Heat Sensitivity

describes a fiber's reaction to heat; these properties identify safe pressing temps

Flammability

describes how a fabric reacts to ignition sources and how it burns

Texture

describes the nature of the textile's surface; identified by both visual and tactile senses

Surface Contour

describes the outer surface of the fiber along its length; may be smooth, serrated, striated, or rough; it affects luster, hand, texture, and apparent soiling of the fabric

Hydrophilic

fibers absorb readily

Photomicrographs

fibers are magnified 250-1000 times

Esters (Polyester)

fibers based on synthetic organic compounds; tend to be non absorbant, lightweight, resistant to wrinkling, resistant to most chemicals, and melt when exposed to flames or high heat

Generic Group

fibers in this type of group have similar chemical compositions; the properties in one group differ from those in another

Pilling

formation of balls of fiber on the fabric surface; often occurs when fibers of differing abrasion resistance (such as cotton and polyester) are combined in one fabric

Oleophilic

have a strong attraction or affinity for oil

Hydrophobic

have little or no absorbency; are often OLEOPHILLIC; problems with static are more likely to develop in these because they do not conduct electrons readily

Hydrogen Bonds, Van Der Waals Forces

intermolecular forces that hold molecular chains together; the closer the chains are to each other the stronger the bonds; HYDROGEN is the attraction of positive hydrogen atoms of one chain to the negative oxyegen or nitrogen atoms of another; WAALs are weak bonds between atoms tat are physically close together; occur in crystalline areas and help make crystalline polymers stronger than amorphous ones

Filaments

long, continuous fiber strands of indefinite length, measured in miles or kilometers ; may be either monofilament (one filament or multifilament (a number of filaments); can be smooth(silklike)or bulked (crimped in some way-cottonlike or woollike); examples are crepe de chien, acetate taffeta, polyester satin, etc.; sold by denier of the yarn or tow

Manufactured (Man-Made) Fibers

made into fiber form from chemical compounds produced in manufacturing facilities, and include such fibers as acrylic used in sweaters and awnings and aramid used in bullet-proof vests and brake liners. TABLE 3.1.

Density (Specific Gravity)

measure of fiber weight per unit volume; lower-density fibers can be made into thick fabrics that are more comfortable than high-density fibers that result in heavy fabrics; fibers with the same diameter may not have the same denier or tex value since fiber density affects weight

Oriented

molecular chains that are crystalline and parallel to the fiber's lengthwise axis; fibers that are highly oriented are also highly crystaline- however highly crystalline fibers are not always highly oriented- and they are strong and stiff, recover quickly from stretch, and are nonabsorbent and difficult to dye (polyester, nylon, aramid)

Edge Abrason

occurs when the textile is folded

Flex Abrasion

occurs when the textile is moving and bending

Sustainability

practices and policies that reduce enviornmentla pollution and do not exploit poeple or natural resources in meeting the lifestyle needs of the present without compromising the future

Filament Tow

produced as a loose rope of several thousand fibers, is crimped or textured, and cut to staple length

Dyeability

receptive to coloration by dyes; fibers that absorb water quickly dye well and have good dye affinity

Fiber Crimp

refers to the waves, bends, twist, coils, or curls along the length of the fiber; increases cohesiveness, resiliency, resistance to abrasion, strectch, bulk, anad warmth; increases absorbency and skin-contact comfort, but reduces luster; helps trap air within the fabric and next to the skin, making the fabric warmer; inherent crimp occurs in wool; exists iin an undeveloped state in bicomponent manufactured fibers in which it is developed in the fabric or the garment (like a sweater) with heat or moister during finishing

Compressibility

resistance to crushing

Aging Resistance

resistance to deleterious changes over time

Moth Resistance

resistance to insect damage, including moths, beetles, crickets, roahces, and spiders

Luster

results from the way light is reflected by a surface; BRIGHT fibers have a high luster, MEDIUM-LUSTER fibers are semibright or semidull

Residual Shrinkage

shirnkage that occurs after the first care cycle

Staple Fibers

short fibers measured in inches or centimeters (2-46 cm); except for silk, all natural fibers are staple; used to produce spun yarn fabrics; sold by denier and fiber length

Fiber Properties Affected By Orientation and Crystallinity

strength, elongation, moisture absorption, abrasion resistance, and dyeability; amorphous fibers such as wool, cotton, and rayon are relatively weak and easily elongated but have poor elasticity and good moisture absorbency, dyeability, and flexibility

Spinning

term used to describe extruding manufactured fibers

Flexibility

the ability to bend repeatedly without breaking

Allergenic Potential

the ability to cause physical reactions such as skin redness resulting from exposure to the fiber

Fabric Crimp

the bends caused by distortion of yarns due to weaving and knitting; when a yarn is unraveled from a fabric, fabric crimp can easily be seen in the yarn and in the fibers removed from the yarn

Cross-Sectional Shape

the cross-sectional shape of a fiber affects luster, bulk, body, texture, and hand; ROUND, DOG-BONE, TRIANGULAR, LOBAL, MULTISIDED, OR HALLOW (FIGURE 3.3)

Elongation

the degree to which a fiber may be stretched without breaking; measured as percent elongation at break by measuring the change in length and comparing that to the original length; should be considered in relation to elasticity

Degree of Polymerization

the number of molecules connected in a chain; long chains indicate a high degree of polymerization and high degree of fiber strength; short chains indicate low degree and low strength (like rayon); length can also be described as weight

Mildew Resistance

the resistance to the growth of mold, mildew, or fungus

Drape

the way a fabric falls over a 3D form like a body or table

Hand

the way a textile feels to the skin

Care

treatements that are required to maintain the new look of a textile product during use, cleaning, or storage

Parts of a Manufactured Fiber

usually consist of a skin and a core

Tex

weight in grams of 1000 meters of fiber or yarn

Denier

weight in grams of 9000 meters of fiber or yarn; when used to describe a fiber, denier refers to the fineness or coarseness of the fibers- small numbers describe fine fibers, and large numbers describe coarse fibers; related to end use

Polymerization

when small molecules- monomers- join together to form a polymer (a long chain); creates the molecular chains that make of fibers

Amorphous

when the chains are arranged in a random or disorganized way within the fiber

Crystalline

when the chains are organized parallel to each other