Chapter 4 Test

Question 1

What is the most common type of regenerated fiber?

Answer 1

Rayon

Question 2

What is polyester?

Answer 2

A common synthetic polymer fiber that is added to many natural fibers to make them stronger

Question 3

What are some disadvantages of manufactured fibers?

Answer 3

They can deteriorate in bright sunlight and melt at a lower temperature than natural fibers

Question 4

What are fibers woven into?

Answer 4

Textile

Question 5

What are fibers that are spun together called?

Answer 5

Yarn or thread

Question 6

What’s the term used when fibers are transferred directly from a victim to a suspect or vice versa?

Answer 6

Direct transfer

Question 7

What is the difference between primary transfer, secondary transfer, and direct transfer?

Answer 7

A direct transfer is the passing of evidence from victim to suspect or vice versa; secondary transfer is the transfer of evidence such as a fiber from a source to a person and then to another person.

Question 8

Within 24 hours, how many estimated fibers could have been lost from the victim in an investigation?

Answer 8

95%

Question 9

What are some questions forensic scientists will ask?

Answer 9

What type of fiber is it (composition and rarity)? What color is it? Does the dye match clothes or other objects? How many fibers were found? Where was the fiber found? Where did the fiber originate? Were there multiple fiber transfers? What crime was committed and the time between the crime and the discovery?

Question 10

What are the ways fiber evidence can be gathered?

Answer 10

Using tape, forceps, a vacuum, or a sticky lint roller

Question 11

What methods can analyze fibers without damaging them?

Answer 11

With a light microscope using polarizing light microscopy, infrared spectroscopy, microspectrophotometry, and ultraviolet light analysis

Question 12

Where do natural fibers come from?

Answer 12

Animals, plants, and minerals

Question 13

Where are natural plant fibers produced from?

Answer 13

Seeds, fruits, stems, and leaves

Question 14

What is cellulose?

Answer 14

The polymer that all plant fibers have in common, made of glucose, which allows fibers to absorb water but not dissolve.

Question 15

What is protein?

Answer 15

The polymer that animal fibers all have in common.

Question 16

What is cotton?

Answer 16

Cotton is the most common plant fiber in textiles. It has an irregular diameter and doesn’t reflect light to your eye or appear shiny. It is found in the seedpod of the cotton plant and can be easily woven and dyed.

Question 17

What is hemp?

Answer 17

Hemp is a stem fiber similar to flax, used for a long time in Asia, and has gained popularity in North America. It is strong and dense, highly crystalline, and resists rot and light damage.

Question 18

What is jute?

Answer 18

Jute fibers make too coarse textiles, but they are strong, dense, and highly crystalline. They resist rot and light damage and are used for mats, rope, and twine.

Question 19

What is fiberglass?

Answer 19

It is the fiber form of glass; it is a mineral fiber.

Question 20

In the 19th century, only plant and animal fibers were only used to make textiles. Half the fibers are produced synthetically, however, what are they categorized as?

Answer 20

regenerated fibers or synthetic polymer fibers.

Question 21

What are the different names of weave patterns?

Answer 21

The weave patterns are plain, basket, satin, twill, and leno.

Question 22

What is tabby?

Answer 22

Tabby is another name for the plain weave and is the simplest pattern.

Question 23

What is twill?

Answer 23

Twill weaves are very strong, dense, and compact, have different faces, and diagonal designs on the surface. It is when a weft is woven over three or more warps and then under one.

Question 24

What is satin?

Answer 24

Satin weaves are not durable, tend to snag and break during wear, have a shiny surface, high light reflectance, and little friction with other garments. It is when one weft crosses over three or more warp threads.

Question 25

What is meant by a thread count?

Answer 25

The number of threads that are packed together for any given amount of fabric. It is the number of horizontal weft threads and vertical warp threads in a square inch of fabric.

Question 26

What is manila?

Answer 26

This is the fiber extracted from the leaves of the abaca plant. The fiber bundles are taken from the surface of the leaves.

Question 27

What is linen?

Answer 27

Linen is made from the stem fiber flax. It has short and brittle fibers but is longer than cotton, is smooth, shiny, and resists wear.

Question 28

What is abaca?

Answer 28

The plant is similar to a banana tree; its leaves hold the fiber manila.