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Tuesday Lecture – Fibers and Dyes . Reading: Textbook, Chapter 15. Collect assignments – plant-derived chemicals added to food products. Fibers - History. Use of plant fibers seems to predate that of animal fibers

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Tuesday lecture fibers and dyes
Tuesday Lecture – Fibers and Dyes

Reading: Textbook, Chapter 15



Fibers history
Fibers - History food products

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 history1
Fibers - History food products

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

10,000 yrs ago – linen (from Linum) in Turkey

Fig. 15.1, p. 556


Fibers history2
Fibers - History food products

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

10,000 yrs ago – linen (from Linum) in Turkey

8,000 yrs ago – fiber sandals in Missouri

Fig. 15.1, p. 556


Fibers history3
Fibers - History food products

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

10,000 yrs ago – linen (from Linum) in Turkey

8,000 yrs ago – fiber sandals in Missouri

7,000 yrs ago – sheep domesticated

Fig. 15.1, p. 556


Fibers history4
Fibers - History food products

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

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

Fig. 15.1, p. 556


Fibers history5
Fibers - History food products

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

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

Fig. 15.1, p. 556


Plant vs animal fibers
Plant vs. Animal Fibers food products

  • Plant fibers: composed – partly - of cellulose

  • Animal fibers: composed of protein molecules

Fig. 15.2, p. 557


Plant vs animal fibers1
Plant vs. Animal Fibers food products

  • 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 fibers2
Plant vs. Animal Fibers food products

  • 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 fibers3
Plant vs. Animal Fibers food products

  • 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 fibers4
Plant vs. Animal Fibers food products

  • 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 fibers
Classification of Fibers food products

  • Seed/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 hemp

Material % Cellulose

Cotton 98

Ramie 86

Hemp 65

Jute 58

Deciduous woods 41-42

Coniferous woods 41-44

Cornstalks 43

Wheat straw 42


Classification of fibers1
Classification of Fibers food products

  • Seed/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 hemp

Material % Cellulose

Cotton 98

Ramie 86

Hemp 65

Jute 58

Deciduous woods 41-42

Coniferous woods 41-44

Cornstalks 43

Wheat straw 42


Classification of fibers2
Classification of Fibers food products

  • Seed/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 hemp

Material % Cellulose

Cotton 98

Ramie 86

Hemp 65

Jute 58

Deciduous woods 41-42

Coniferous woods 41-44

Cornstalks 43

Wheat straw 42


Fiber extraction
Fiber Extraction food products

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 extraction1
Fiber Extraction food products

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 extraction2
Fiber Extraction food products

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


Seed fibers cotton

Fig. 15.7, p. 562 food products

Seed Fibers - Cotton


Cotton ancient history
Cotton – Ancient History food products

Fig. 15.9, p. 564

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

G. arboreum

G. hirsutum

Diploids AA

Tetraploids AADD

G. herbaceum

G. barbadense


Cotton ancient history1
Cotton – Ancient History food products

Fig. 15.9, p. 564

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

G. arboreum

G. hirsutum

Diploids AA

Tetraploids AADD

G. herbaceum

G. barbadense


Cotton ancient history2
Cotton – Ancient History food products

Fig. 15.9, p. 564

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

G. arboreum

G. hirsutum

Diploids AA

Tetraploids AADD

G. herbaceum

G. barbadense


Cotton more recent history
Cotton – More Recent History food products

Hand Labor – Associated with Slavery in U.S.

Fig. 15.11, p. 565

Cotton Gin – Enhanced Value


Cotton spinning
Cotton - Spinning food products


Cotton today
Cotton - Today food products

Cotton – Issues:

Chemical Use

Irrigation


Cotton cloth details
Cotton Cloth - Details food products

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
Dye Plants food products

Paradox: We associate plants with beautiful colors, yet most plant pigments do not make good dyes


Dye plants1
Dye Plants food products

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 plants2
Dye Plants food products

  • 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


Reminder
Reminder food products

This Thursday, April 21 – class will meet at UT Institute of Agriculture Gardens, next to the Vet School. Dress appropriately to be outside and take a garden tour.