Lesson 5 Page 1
Discover: I Spy Fibre
Fibres are the tiny threads that make up any type of fabric. Fibres can come from natural sources such as cotton or wool.
Some fibres are synthetic or man-made. Examples are polyester, fleece, or nylon.
Fibres often are left behind from the clothing a person was wearing or from contact they had with other items such as furniture, car upholstery, blankets, ropes, etc. Forensic scientists can collect these fibres and analyze them to gain more information about their source.
Fibres will look unique when examined closely under a microscope. Some things investigators look at include
- Colour
- Texture – Does it look smooth or fuzzy?
- Diameter – How thick is the fibre?
- Shape – Is it straight or curly? Hollow or solid?
Investigators also test fibres with various chemicals to see how they react. By combining their knowledge of physical and chemical characteristics, investigators can determine what kind of fibre was left at a scene and possibly where it may have come from.
Notebook: How do various fibres look?
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Science Connection
In addition to the appearance of various fibres, scientists can analyze how fibres react to various chemicals. Some common chemicals used in fibre analysis include acetone (nail polish remover), vinegar, and bleach.
If you are interested in learning more about chemical fibre analysis, you can try the Fibre Analysis activity on the Wonderville website. Be sure to ask for adult permission and help before doing this activity.