tuesday lecture – fibers and dyes reading: textbook, chapter 15
TRANSCRIPT
Fibers - History
Use of plant fibers seems to predate that of animal fibers
Note: relatively few plants or animals produce fibers that can be woven or spun – use seems fairly recent
Fig. 15.1, p. 556
Fibers - History
10,000 yrs ago – linen (from Linum) in Turkey
Use of plant fibers seems to predate that of animal fibers
Note: relatively few plants or animals produce fibers that can be woven or spun – use seems fairly recent
Fig. 15.1, p. 556
Fibers - History
10,000 yrs ago – linen (from Linum) in Turkey
8,000 yrs ago – fiber sandals in Missouri
Use of plant fibers seems to predate that of animal fibers
Note: relatively few plants or animals produce fibers that can be woven or spun – use seems fairly recent
Fig. 15.1, p. 556
Fibers - History
10,000 yrs ago – linen (from Linum) in Turkey
8,000 yrs ago – fiber sandals in Missouri
7,000 yrs ago – sheep domesticated
Use of plant fibers seems to predate that of animal fibers
Note: relatively few plants or animals produce fibers that can be woven or spun – use seems fairly recent
Fig. 15.1, p. 556
Fibers - History
10,000 yrs ago – linen (from Linum) in Turkey
8,000 yrs ago – fiber sandals in Missouri
7,000 yrs ago – sheep domesticated
5,400 yrs ago – cotton fibers used in Mexico
Use of plant fibers seems to predate that of animal fibers
Note: relatively few plants or animals produce fibers that can be woven or spun – use seems fairly recent
Fig. 15.1, p. 556
Fibers - History
10,000 yrs ago – linen (from Linum) in Turkey
8,000 yrs ago – fiber sandals in Missouri
7,000 yrs ago – sheep domesticated
5,400 yrs ago – cotton fibers used in Mexico
5,000 yrs ago – silk in Asia
Use of plant fibers seems to predate that of animal fibers
Note: relatively few plants or animals produce fibers that can be woven or spun – use seems fairly recent
Fig. 15.1, p. 556
Plant vs. Animal Fibers
Plant fibers: composed – partly - of cellulose
-
Animal fibers: composed of protein molecules
Fig. 15.2, p. 557
Plant vs. Animal Fibers
Plant fibers: composed – partly - of cellulose
- can be heated
- hard to dye
- attacked by fungi, mold, termites
- less elastic but more absorbent of water
Animal fibers: composed of protein molecules
- denatured by heat brittle
-
Fig. 15.2, p. 557
Plant vs. Animal Fibers
Plant fibers: composed – partly - of cellulose
- can be heated
- hard to dye
- attacked by fungi, mold, termites
- less elastic but more absorbent of water
Animal fibers: composed of protein molecules
- denatured by heat brittle
- readily accept dyes
Fig. 15.2, p. 557
Plant vs. Animal Fibers
Plant fibers: composed – partly - of cellulose
- can be heated
- hard to dye
- attacked by fungi, mold, termites
- less elastic but more absorbent of water
Animal fibers: composed of protein molecules
- denatured by heat brittle
- readily accept dyes
- attacked by moths, silverfish
Fig. 15.2, p. 557
Plant vs. Animal Fibers
Plant fibers: composed – partly - of cellulose
- can be heated
- hard to dye
- attacked by fungi, mold, termites
- less elastic but more absorbent of water
Animal fibers: composed of protein molecules
- denatured by heat brittle
- readily accept dyes
- attacked by moths, silverfish
- more elastic, less absorbent of water
Fig. 15.2, p. 557
Classification of FibersSeed/Fruit Fibers – aid in seed dispersal
- cotton, coir, kapok
Bast Fibers – from phloem of stem
- hemp, jute, ramie, linen
Hard Fibers – from leaves of monocots
- sisal, henequen, Manila hempMaterial % Cellulose
Cotton 98
Ramie 86
Hemp 65
Jute 58
Deciduous woods 41-42
Coniferous woods 41-44
Cornstalks 43
Wheat straw 42
Classification of FibersSeed/Fruit Fibers – aid in seed dispersal
- cotton, coir, kapok
Bast Fibers – from phloem of stem
- hemp, jute, ramie, linen
Hard Fibers – from leaves of monocots
- sisal, henequen, Manila hempMaterial % Cellulose
Cotton 98
Ramie 86
Hemp 65
Jute 58
Deciduous woods 41-42
Coniferous woods 41-44
Cornstalks 43
Wheat straw 42
Classification of FibersSeed/Fruit Fibers – aid in seed dispersal
- cotton, coir, kapok
Bast Fibers – from phloem of stem
- hemp, jute, ramie, linen
Hard Fibers – from leaves of monocots
- sisal, henequen, Manila hempMaterial % Cellulose
Cotton 98
Ramie 86
Hemp 65
Jute 58
Deciduous woods 41-42
Coniferous woods 41-44
Cornstalks 43
Wheat straw 42
Fiber Extraction
Seed Fibers (Cotton) – actually trichomes, not fibers
Ginning – separates fibers from seeds
Mostly Bast Fibers:
Retting – rots away non-fiber parts
Scutching – beat and scraping retted plant material to remove broken pieces of woody matter
Hackling – drawing a mass of fibers across pins to separate and align fibers
Leaf Fibers
Decorticating – crushing plant material and scraping away the nonfibrous material
Fiber Extraction
Seed Fibers (Cotton) – actually trichomes, not fibers
Ginning – separates fibers from seeds
Mostly Bast Fibers:
Retting – rots away non-fiber parts
Scutching – beat and scraping retted plant material to remove broken pieces of woody matter
Hackling – drawing a mass of fibers across pins to separate and align fibers
Leaf Fibers
Decorticating – crushing plant material and scraping away the nonfibrous material
Fiber Extraction
Seed Fibers (Cotton) – actually trichomes, not fibers
Ginning – separates fibers from seeds
Mostly Bast Fibers:
Retting – rots away non-fiber parts
Scutching – beat and scraping retted plant material to remove broken pieces of woody matter
Hackling – drawing a mass of fibers across pins to separate and align fibers
Leaf Fibers
Decorticating – crushing plant material and scraping away the nonfibrous material
Cotton – Ancient History
G. barbadense
G. hirsutum
G. herbaceum
G. arboreum
Tetraploids AADD
Diploids AA
4 independent domestications of cotton
Problem: New World domesticates – have one genome present in wild only in Old World
Possible resolution: AA genome predates continental separation
Fig. 15.9, p. 564
Cotton – Ancient History
G. barbadense
G. hirsutum
G. herbaceum
G. arboreum
Tetraploids AADD
Diploids AA
4 independent domestications of cotton
Problem: New World domesticates – have one genome present in wild only in Old World
Possible resolution: AA genome predates continental separation
Fig. 15.9, p. 564
Cotton – Ancient History
G. barbadense
G. hirsutum
G. herbaceum
G. arboreum
Tetraploids AADD
Diploids AA
4 independent domestications of cotton
Problem: New World domesticates – have one genome present in wild only in Old World
Possible resolution: AA genome predates continental separation
Fig. 15.9, p. 564
Cotton – More Recent HistoryHand Labor – Associated with Slavery in U.S.
Cotton Gin – Enhanced Value
Fig. 15.11, p. 565
Cotton Cloth - Details
Cleaning – boiling in caustic soda, then treat with hydrogen peroxide removes pectins, waxes; lightens color of fibers
Mercerizing (invented by J. Mercer) – soak thread or textile under pressure in caustic soda fibers swell, change shape
Sizing – add starch or gel to thread, fills in irregularities, strengthens
Sanforization – ammonia process, swells fibers and prevents shrinking
Permanent press – use chemicals to cross-link cellulose polymers garment retains shape even after washing
Dye Plants
Paradox: We associate plants with beautiful colors, yet most plant pigments do not make good dyes
Dye Plants
Paradox: We associate plants with beautiful colors, yet most plant pigments do not make good dyes
Resolution: Most plant pigments are chemically instable – when removed from the environment of the plant cell they are quickly degraded or washed away
Dye Plants
Paradox: We associate plants with beautiful colors, yet most plant pigments do not make good dyes
Resolution: Most plant pigments are chemically instable – when removed from the environment of the plant cell they are quickly degraded or washed away
Plant Dyes:
- must be chemically stable (many oxidize when exposed to air)
- must bind to object being dyed (=fastness)
Mordant: chemical that increases adherence of dye to fabric
- may also change color of dye