Textile Fibers and Cordage Evidence

Cards (82)

  • Textile Fibers
    In general and broad sense, the word "textile" is derived from the Latin word "textillis" and the French "textere", which means "to weave".
  • Yarn
    consists of fibers or filaments that have been twisted together
  • Textile Production
    1. Textiles begin as fibers.
    2. Fibers are made into fabrics.
    3. Fabrics are made into clothing and other products.
  • Fiber Evidence
    smallest unit of a textile material that has a length many times greater than its diameter
  • Fibers can be spun with other fibers to form a yarn that can be woven or knitted into a fabric.
  • Classification of Fibers
    Major Classifications:
    1. Natural Fibers
    2. Natural/Man-made Fibers
    3. Man-Made Fibers
  • Non-Technical Test of Textile Fibers: Feeling test
    involves touching and feeling the fabric to know its component fibers
  • Feeling Test
    • Wool fabrics will feel warm when touched.
    • Fabric made up of plant fibers such as cotton, linen, and rayon fabrics will feel cool to touch.
  • Non-technical Test for Textile Fibers: Burning or Ignition Test
    • preliminary macroscopic examination
    • determines whether fiber is mineral, animal, or vegetable fiber
    • destructive test
  • Burning or Ignition Test
    A single fiber is applied with flame at one end and the following are noted:
    • Manner of Burning
    • Odor of Fumes
    • Appearance of Burnt End
    • Color of Ash
    • Action of fumes on moistened red and blue litmus paper
    • Effect of litmus on a piece of filter paper moistened with lead acetare.
  • Ignition Test Result: Natural Fiber
    Ash is soft and odor is of burning hair or paper.
  • Ignition Test Result
    Cellulosic Fibers
    • Burn rapidly with yellow flame
    • Afterglow
    • Soft gray ash
  • Ignition Test Result
    Cotton
    • ignites on contact with flames
    • burns quickly
    • yellowish to orange afterglow
    • does not melt
    • odor of burning paper, leaves, or wood
    • fine, feathery, gray ash
  • Ignition Test Result
    Hemp, Linen, and Ramie yields the same results as cotton.
  • Ignition Test Result
    Rayon
    • Burns slowly without flame
    • slight melting
    • soft black ash
  • Ignition Test Result
    Silk
    • burns slowly, burns itself out
    • does not melt
    • shrinks from the flame
    • black residue
    • hollow irregular bead, becomes gritty grayish-black ash powder
  • Ignition Test Result
    Tencel yields the same result as Rayon.
  • Ignition Test Result
    Wool and Other Protein Fibers
    • Burns with an orange sputter color
    • does not melt
    • shrinks from the flame
    • strong odor of burning hair or feathers
    • black residue
    • hollow irregular bead, becomes gritty black ash powder
    • burns itself out
  • Ignition Test Result
    Synthetic Fiber
    • both burn and melt
    • tend to shrink away from the flame
    • burn with an acrid, chemical, or vinegar-like odor
    • leaves a plastic bead
  • Ignition Test Result
    Acrylic
    • Flames and burns rapidly with hot, sputtering flame
    • black smoke
    • acrid fishy odor
    • hard, irregularly-shaped residue
  • Ignition Test Result
    Acetate
    • flames and burns quickly
    • odor similar to burning paper and hot vinegar
    • hard, dark, solid bead residue
  • Ignition Test Result
    Nylon
    • shrink from the flame
    • burn slowly giving off black smoke
    • odor likened to celery
    • residue: initially a hard, cream-colored bead that becomes darker
  • Ignition test result
    Olefin/Polyolefin
    • chemical type odor
    • hard, tan-colored bead
    • flames create black smoke
  • Ignition test result
    Polyester
    • shrink from the flame giving off black smoke
    • somewhat sweet chemical odor
    • residue: hard, cream-colored bead that becomes darker tan
  • Ignition Test Result
    Spandex
    • burns and melt
    • does not shrink from the flame
    • chemical type odor
    • residue: soft sticky black ash
  • Technical Test for Textile Fibers
    1. Microscopic Test
    2. Fluorescent Test
    3. Chemical Test
  • Microscopic Test of Natural Fibers
    Cotton
    • single elongated cell
    • flat, spirally twisted ribbon-like tube with granular surface
    Mercerized Cotton - no natural twist, swollen, straight, smooth and rounded with a shining surface
  • Microscopic Test of Natural Fibers
    Linen
    • having multiple sided cylindrical filaments with fine pointed edges
    • filaments show nodes at intervals
    • looks like a bamboo stick having joints that result into a little unevenness
  • Microscopic Test of Natural Fibers
    Wool
    • irregular, roughly cylindrical, multi-cellular structure with tapered ends
  • Three Basic Layers of Wool
    1. Epidermis - outer layer
    2. Cortex - middle layer
    3. Medulla - inner layer
    Note: Medulla is seen only in coarse and medium wool fibers under highly powerful microscope.
  • Microscopic Test of Natural Fibers
    Silk
    • Fine and Lustrous filaments are shown clearly looking like a transparent rods with triangular shape
    • Elliptical shape
    Wild silk/Tussah fiber - flattened, coarse, thick, and broader fiber having fine wavy lines all across its surface
  • Microscopic Test of Manmade Fibers

    These fibers are difficult to identify through microscope because of similar appearance of many fibers.
  • Microscopic Test of Natural Fibers
    Rayon
    • uniform diameter with glass-like shine
    • if delustered, fiber shows marks similar to pepper
    • viscose fiber looks irregular
  • Microscopic Test of Manmade Fibers
    Acetate
    • lesser irregular than viscose fiber of rayon
    • has indentations that look like occasional marks when viewed longitudinally
  • Microscopic Test of Manmade Fibers
    Nylon
    • generally appears fine, round, smooth, and translucent
    • shiny appearance
  • Microscopic Test of Manmade Fibers
    Aramid
    • looks smooth and straight
    • may be round like a peanut's shape
  • Microscopic Test of Manmade Fibers
    Polyester
    • smooth, straight, round
    • changes in context of texture and luster due to finishing processes
  • Microscopic Test of Manmade Fibers
    Spandex
    • appearing like groups of fibers fused together
    • Lycra fiber - fused multifilament
    • individual fibers are dotted and in shape like that of a dog-bone
    • straight when viewed longitudinally
  • Microscopic Test of Manmade Fibers
    Polypropylene
    • looks somewhat round (cross sectional)
    • looks straight and smooth (longitudinally)
  • Microscopic Test of Manmade Fibers
    Glass
    • looks smooth, round, translucent, shiny, and flexible