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Fibers PowerPoint Presentation

Fibers

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Fibers

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  1. Fibers Hair & fiber note No. 3

  2. Fiber • A fiber is the smallest unit of a textile material (fabric) • A fiber has a length many times greater than its diameter • There are two types of fibers: • Natural fibers • Synthetic (man-made) fibers

  3. Natural fibers • Originating from plants & animals • Cotton fibers Flax (linen) wool • Exhibiting more random texture

  4. Synthetic fibers • Man-made fibers • Polyester Acrylic Rayon • Exhibiting a uniform, un-natural texture

  5. Fibers as evidence • Information to look for • Fiber types and color • Fiber number – The greater the number, the more likely an actual contact occurred • Fiber location – on different areas of the body or on specific items at the crime scene • Make fiber association with a specific source – fabrics from victim, suspect, and/or scene

  6. Identification and Comparison of Fibers • Microscopic examination • Color – compositional differences in the dyes • Fiber surface – delustering particles that may be added by manufactures • Microspectrophotometer – compares fiber colors through spectral patterns • Chromatography – gives a more detailed analysis of the dye composition