RLG,+RY,+RW,+KS,+DH+-+7+fibers

__**FIBERS**__



Intro


 * Useful Vocabulary:**

Amorphous- no defined shape, loose arrangement of polymers

Crystalline- regular shape, polymers packed side by side

Direct transfer- passing of evidence between people

Fiber- smallest unit of a textile

Mineral fiber- mineral crystals in a recognizable pattern

Monomer- small molecule that may bond to monomers to form a polymer

Natural fiber- naturally produced fiber

Polymer- long chains of repeating units

Synthetic fiber- fiber from a man-made substance

Secondary transfer- transfer from evidence from a source to a person (carpet to person)

Textile- material made by interlacing yarns

Yarn- fibers spun together


 * Differences In Natural and Synthetic Fibers**

Cotton: "flattened hose" appearance - up to 2 inches long, tapering to a blunt point - may have a frayed "root" - hollow core not always visible

Flax: "bamboo stick" appearance - sraight with angles but not very curved - "nodes" are visible as an X every inch or so - often occur in bundles of several fibers

Silk: - do not taper, yet exhibit small variations in diameter - may be paired (raw silk) with another fiber - no internal structures

Wool: - surface scales may be visible - hollow or partially hollow core - fibers up to 3 inches long tapering to fine point

Man-made: - vary widely in cross- sectional shape and diameter - generally straight to gentle curves - very uniform in diameter - may have surface treatment that appears as spots, stains, or pits



Different Textile Weave Patterns
Plain: contains alternating warp and weft threads, firm, wears well, snag resistant, low tear strength, tends to wrinkle

Basket: contains alternating pattern of two weft threads crossing two warp threads, has open or porous weave, does not wrinkle, not very durable, tends to distort as yarns shift, shrinks when washed

Satin: contains one weft crossing over three or more warp threads, not durable, tends to snag and break during wear, has shiny surface, very reflective of light, creates little friction with other garments

Twill: weft is woven over three or more warps and then under one, pattern in next row shifted over one to the left or right by one warp thread, very strong, dense and compact, has different faces, shows diagonal design on surface, soft and pliable

Leno: uses two warp threads and double weft thread, two adjacent warp threads cross over each other, weft travels left to right and woven between two warp threads