Lecture 18 - Cotton and Flax

Question 1

the most valuable fibers are those that are pure _________ and white

Answer 1

cellulose

Question 2

what material in fibers make it much poorer quality, as it is not as strong and more brownish in color

Answer 2

lignin

Question 3

how are fibers classified

Answer 3

according to their use
textile, cordage, filling, and mineral fibers

Question 4

how are natural fibers subdivided

Answer 4

subdivided based on their origins

Question 5

surface fibers

Answer 5

outer layer of leaves, seeds, or fruits (ex: cotton)
bast/soft fibers are clusters of phloem fibers found in the inner bark of some dicot stems

Question 6

bast/soft fibers

Answer 6

bast/soft fibers are clusters of phloem fibers found in the inner bark of some dicot stems

Question 7

hard/leaf fibers

Answer 7

produced from the vascular bundles or veins in leaves ( made up of both xylem, phloem, and surrounding sheath fibers

Question 8

benefits of using natural fibers compared to others

Answer 8

a reduction in cost and weight, light weight, and safer

Question 9

cotton family and genus

Answer 9

family - Malvaceae
genus - Gossypium

Question 10

physical description of cotton

Answer 10

perennial shrub grown as an annual with seeds packed into a capsule (cotton ball)

Question 11

what was one of the first fiber plants to be domesticated by humans

Answer 11

cotton

Question 12

major cotton producing countries

Answer 12

china, US, india, pakistan

Question 13

use of cotton

Answer 13

cloth, paper, lint, vegetable oil, margarine, feed meals

Question 14

most commonly produced cotton species

Answer 14

G. hirsutum

Question 15

Upland cotton ( Gossypium hirsutum)

Answer 15

most commonly produced. Uses a lot pesticides

Question 16

cotton seeding rate

Answer 16

24-31kg/ha

Question 17

how long does cotton take to mature

Answer 17

5-6 months

Question 18

how is cotton harvested

Answer 18

hand picked because it produces higher quality

Question 19

cotton processing steps

Answer 19

Ginning - removal of seeds and debris
Carding - fibers are combed to produce web
silver - twisting web into rope
drawing - more alignment
spinning
cleaning - boiled and bleached
mercerization - stretched and chemical bath
sizing - stiffening agent
permanent press - chemicals used to cross-link polymers

Question 20

spindles and doffers cotton picker

Answer 20

machinery that pulls cotton out of bolls

Question 21

major pest of cotton and how it is controlled

Answer 21

cotton bollworm
controlled through predators, insect ides, resistant varieties

Question 22

what is bt cotton

Answer 22

transgeneic cotton that is resistant to bollworms

Question 23

scientific name of flax

Answer 23

linum usitatissimum

Question 24

what type of material does flax make

Answer 24

linen

Question 25

what might be the oldest fabric made using plants

Answer 25

linen

Question 26

flax center of diversity

Answer 26

Near east

Question 27

wild progenitor of flax

Answer 27

linum bienne

Question 28

grouping of cultivated flax

Answer 28

fibre flax
large-seeded flax
intermediate flax
dehiscent flax

Question 29

current theory for flax domestication

Answer 29

disruptive selection

Question 30

what type of fibre is flax

Answer 30

soft bast fibre made of phloem cell bundles

Question 31

how is linen prepared

Answer 31

retting the stems (allow microbes to ferment on them)- done by leaving in moisture
retted fibers are dried than broken and bleached by sun

Question 32

what is abaca or manila hemp used for

Answer 32

used in tea bags, dollar bills, manila envelopes, cigarette filters, and rope

Question 33

difference between flax and hemp fibers

Answer 33

hemp is stiffer and used in cordage, canvas, and sail cloth

Question 34

what are jute fibers used for

Answer 34

used as sacks, twine, or carpet backing. Fibers are rough/brittle and don’t take dye