Transcript Fiber Science

Fiber Science
Animal Fibers Lesson 2
I.
Wool production
A.Wool has likely been used longer than any other
fiber by humans to make clothing
B. Early humans may have started using sheep skins
for clothing
1.
Soon discovered that the wool fibers
could be twisted into thread
2.
Realized animals did not have to be
killed to harvest fibers and the animal continued
to grow wool fiber
3.
May even have started a selective
breeding program to develop sheep with finer
wool
C.
Wool is highly desired for fabric
1. Durable
2. Warm in the winter
3. Can be worn in the summer
because it absorbs moisture
4. Lends itself to a variety of uses
a. Fine garments
b. Durable garments
c. Tapestriesd.
d.
Blankets
e. Rugs
D.
Wool animals
1.
Sheep
2.
Angora goats
3.
Alpacas
4.
LLamas
Wool characteristics
1. Wool is made of type
of protein called keratin (also found in horns,
hooves, fingernails, and skins)
2. On animals, wool has both
primary follicles that produce coarser, outer hair
(designed to keep water away from body); and
finer, inner hairs that provide insulation
E.
3. Wool grows by adding cells to the
hair structure
a. Cells overlap and resemble
scales
b. Scales help fibers mat and hold
together (i.e. felt, yarn)
4. Wool has a wavy appearance =
crimp; the more crimp, the more
desirable the wool
• 5. The skin secretes a grease-like substance
from the skin that helps keep the wool soft,
pliant, and able to shed water (live animal
substance = yolk; processed substance =
lanolin)
F.
Wool processing
1.Wool is shorn from the sheep
2.Shorn wool is bundled together; not cleaned
and called grease wool
3.Process of cleaning (removing the yolk/foreign
material) is called scouring
4.Wool is graded (assigned a quality rating)
5.Wool is blended with other wool fibers to
create a particular type of wool fabric
6.After blending, the fibers are untangled (called
carding)
7.Carded fibers are spun and twisted together
to form thread/yarn to be woven into cloth
II.
Silk production
A.Silk probably originated in Ancient China
around 2600 BC
B.Hundreds of years later, silk was produced and
marketed in many parts of Asia
C.Characteristics of silk
1. Silk is the strongest of all natural
fibers and tends to hold its shape well
2. Silk fibers are very fine (.00059 to
.00118 inch in diameter), and very long
(Length of fiber contributes to its strength)
3. Silk is very receptive to dyeing and
shows colors well
4. Silk cloth is comfortable and absorbs
moisture better than any of the other natural
fibers
D. Sericulture
1. Sericulture: culture of the silk worm
2. Out of over 30,000 species of spiders and
113,000 species of insects that make silk
(insect order Lepidoptera); most silk is
produced by the moth Bombyx mori.
3. Thailand, China, and Japan are leading
countries in sericulture
4.
Silk-making process
a.
An adult female moth lays around 700
eggs (no larger than a pinhead) on specially
prepared paper
b.
When the eggs begin to hatch, they are
laid on bamboo
frames covered with mulberry leaves
c.
Tiny larva hatch and feed on the leaves
i.
May devour 30,000 times their
weight at hatching
ii.
May increase their hatch weight
up to 10,000 times
d.The larva grow for a period of about 35 days
i. Larva shed their skins four times
ii. Larva grow to a length of about 3 inches
and ½ inch diameter
e.After the growth period, the larva attaches
itself to a straw structure placed on the pad,
and begins to spin a cocoon
i.
Silk material for the cocoon is
secreted from two glands inside the larva’s
mouth
ii.
Silk is forced out of the mouth
through two openings called spinnerets
iii. The cocoon is completed in 2-3 days
and may contain as much as a mile of silk
filament
f. As the larva begins to go through
metamorphosis, it is killed
with heat and
the silk collected – some larva are allowed to
continue living, grow into adults and are used
for breeding/laying eggs
g. Collection of silk filaments
i.
Each cocoon usually produces about
100 yards of combined filaments
ii.
Silk taken from the cocoon is called
raw silk