Fiber Types
These fibers are made from animal hairs, plant fibers, and minerals
What are natural fibers?
These fibers will look uniform with very little variation between them
What are synthetic fibers?
Fibers can be analyzed under a microscope. Name 2 characteristics that are usually analyzed with a microscope.
What is color, diameter, texture, style...?
Fibers should be picked up with these and placed in a paper bindle
Fiber is considered this type of evidence.
What is trace or class?
These fibers are man-made in a factory
What are synthetic fibers?
These fibers will have a cuticle when viewed under the microscope.
What is wool, cashmere, mohair...?
Fiber dye analysis can be done through this process where a solvent is pulled up a piece or filter paper and the dye composition is separated.
What is Thin Layer Chromatography (TLC)
Apart from by hand, fibers may also be collected with these other two methods.
What is forensic vacuuming and tape lifting?
Clothing may be made out of a pure fabric such as 100% cotton T-shirts or this
This is one of the most common types of fiber. It makes up most of the clothes we wear including T-shirts.
What is cotton?
These natural fibers look like long twisted ribbons under a microscope
What is cotton?
Fibers can be analyzed similarly to paint by vaporizing them and putting them through this 6 letter process.
What is PY-GC-MS?
Fibers embedded firmly in the evidence should be packaged like this.
What is the entire item is sent to the lab wrapped in paper?
Fibers are usually analyzed under this type of microscope that allows the analyst to view two samples at once.
What is a comparison microscope?
This type of synthetic fiber is often used to make parachutes and rope
What is nylon?
Fibers are usually viewed under this kind of microscope where two samples can be viewed simultaneously.
What is a comparison microscope?
Similarly to glass, fibers can be analyzed by measuring how light interacts with them which is called this
What is Refractive index (RI)?
Fibers collected from a unknown origin are called this.
What are questioned samples?
Fiber is not individualizing evidence for this reason.
What is it is too similar to other fabrics or it is mass-produced?
This type of fiber is extremely elastic allowing it to work well with morph suits, activewear, and superhero costumes.
What is Spandex?
A fiber can be cut it half and viewed from the side. This allows the analyst to measure this
What is the diameter or cross-section?
This process measures how infrared light interacts with fibers.
What is Fourier Transform Infrared Spectroscopy or (FTIR)?
Fibers may have come from a source that is still at a crime scene. Gathering fibers from a potential source for comparison is a collection of this type of sample.
What is a known sample?
Linen comes from this type of plant
What is flax?