Textile Fibers and Cordage Evidence

• 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