Fibers Analysis Notes

Forensic Fiber Analysis

ESSENTIAL QUESTIONS

1.
How can you distinguish between a natural and
manufactured fiber?

2.
How can you distinguish between animal and
plant-derived fibers?

3. What techniques are used in forensic fiber

analysis?

Part 1:
What is a fiber?

● A fiber is the smallest unit of a textile material that has a length

many times greater than its diameter.

● A fiber can be spun with other fibers to form a yarn that can be

woven or knitted to form a fabric.

● Fibers can be categorized as one of two types:

○ Natural—derived entirely from plant or animal sources.

○ Manufactured—made from long chains of molecules called

polymers

Multiple Choice

Fibers are classified as either:

• natural fibers or synthetic fibers.

• polymers or synthetic fibers.

• acrylic fibers or plant fibers.

• olefins or synthetic fibers.

Plant–Derived Fibers

● Flax – oldest cultivated (linen)

● Cotton – most prevalent

● Hemp – source of 1st paper

● Bamboo – cellulose fiber

Animal–Derived Fibers

● Silk – derived from silkworm or spider

● Sinew – animal tendon

● Wool – sheep

Animal–Derived Fibers

● Other – cashmere (goat), mohair (goat),

● angora (rabbit), alpaca, camel, and qiviut (muskox)

● Fur – whole pelt

Manufactured Fibers

●

More than half of all fibers used in the production of textile
materials are man-made.

●

Man-made fibers may originate from natural materials such as
cotton or wood (artificial); others originate from chemicals
(synthetic).

●

Rayon –1st artificial fiber from wood

●

Acetate – artificial from wood (satin)

●

Nylon –1st synthetic fiber

●

Acrylic – synthetic wool

●

Polyester – most common synthetic

●

Specialty fibers – Kevlar, Spandex

Natural vs. Synthetic

Multiple Choice

Natural fibers come from:

• animals.

• plants.

• minerals that are mined from the ground.

• All of these choices.

Multiple Choice

The name for man-made fibers is:

• processed fibers
• synthetic fibers
• natural fibers
• modified fibers

Multiple Choice

Hair is composed of a protein called...

• keratin

• medulla

• casein

• cellulose

Multiple Select

Fiber evidence is gathered with:

• vacuums.

• tape.

• glue.

• forceps.

• lint roller.

Multiple Choice

the smallest indivisible unit of a textile, it must be at least 100 times longer than wide.

• fiber

• yarn

• textile

• monomer

Multiple Choice

Which of the answers describe natural fibers?

• rayon, nylon, wool

• cotton, polyester, cashmere

• linen, cotton, silk

• silk, spandex, polyester

Multiple Choice

Which of the following is a synthetic fiber?

• rayon

• silk

• cashmere

• polyester

Multiple Choice

Fibers are considered what kind of evidence? 

• Individual
• Class
• Direct
• Indirect

​Copy the table into your notes. Then use the video on the next slide to fill in the table.