TANNINS - Sources of Tanning Materials

pt. 1 (4th topic)

• Organic compound, glucosidal, acid reaction, very astringent (dry, tightening sensation)

• bitter taste ex. tea

Tannin

Ability to unite/bind with certain types of proteins

• ex. proteins in animal skin

Tannin

It is a process when tannins bind/ unite to protein of animal skin

Tanning

Tannin reacts with ___ ___ producing dark-blue or greenish-black compound

iron salt

Tannin reacts with iron salt producing

dark-blue or greenish-black compound

a strong, flexible, resistant, insoluble substance

leather

liquid inside plant cell

cell sap

Tannin are found in ___ of in specific plant part: (6)

Cell sap

1. Bark

2. wood

3. leaves

4. roots

5. fruits

6. galls

abnormal plant growth because of egg laying activities of insects (twigs)

Galls

what is very old industry

Tanning

Raw chief material in tanning

Hemlock bark

How many tanneries in New England and what is abundant bark (cheapest)

50

Hemlock

Become one of the chief leather markets of the world

Boston

When hemlock bark became scarce what is alternative

oak bark - chestnut - western trees and foreign materials

Source of Tanning Materials (5)

1. Barks

2. Woods

3. Leaves

4. Fruits

5. Roots

4 types of barks for source of Tanning materials

1. Hemlock Barks

2. Oak Barks

3. Mangrove Barks

4. Wattle Barks

• main source of tannins in US

• contains 8-14% tannins

• used for making sheepskin leather, sole leather

Hemlock bark

Scientific name

1. Eastern Hemlock

2. Western Hemlock

1. Tsuga canadensis

2. Tsuga heterphylla

• Widely used to obtain tannin

• Has 4 oak species (chestnut, black, california tanbark, red & white)

Oak barks

Give the 4 oak species

1. Chestnut oak

2. Black oak

3. California tanbark oak

4. Red and White oak

contains 6-11% tannins

Chestnut and black oak

Black oak:

• Produce an extract called __ that gives yellow collor in leather

• 6-11% tannin

quercitron

contain small amount of tannin (species of oak bark)

Red and white oak

Give the Scientific Name

1. Chestnut oak

2. Black oak

3. California tanbark oak

4. Red and White oak

1. Quercus montana

2. Quercus velutina

3. Lithocarpus densiflorus

4. Quercus borealis and Quercus alba

Most important american species oak

Chestnut oak

all ___ contains tannins (bark)

Mangroves

• Very hard and heavy

• contains 22-33% tannin

Mangroves bark

Rarely use alone bec. it gives bad color in leather (bark) and cheapest tanning material

Mangroves bark

Cheapest tanning material (bark)

Mangroves bark

What mangrove species main source?

Red mangrove

Red mangrove scientific name

Rhizophora mangle

• contains very high amount of tannins: 40 - 50% (bark)

• refers to several species of acacia trees

Wattle barks

Wattle bark produces solid, very firm, ___ ___ leather

faintly pink

Wattle bark:

• Give 3 species of acacia tree

1. Acacia dealbata

2. Acacia decurrens

3. Acacia pycnantha

Highest tannin content in barks (source of Tanning materials)

Wattle bark

Give the 2 woods (source of Tanning materials)

1. Chestnut

2. Quebracho

became useful when the tannin extraction process was developed (wood)

Chestnut wood

Worlds most important source of tannin at the present time (wood)

Quebracho

Quebracho means

ax breaker

• Hardest wood (what specific gravity)

• used for railroad tiles

• Quebracho woods

• 1.30 - 1.40

Give the 3 leaves (source of Tanning materials)

1. Sumac leaves

2. Sicillian sumac leaves

3. Gambier leaves

• dried leaves

• the leaves are picked in the fall when they begin to red

Sumac leave

Give the 3 native sumacs leaves

1. Rhus glabra

2. Rhus typhina

3. Rhus copallina

• best for gloves and bookbinding

• Produce pale color, soft texture leather (leaves)

Sicillian sumac leaves

Gambier leaves also called

white cutch

also called white cutch, a resinous substance

Gambier leaves

Give the 3 fruits (source of Tanning materials)

1. Myrobalan

2. Divi divi

3. Valonia

• unripe fruits

• Produce spongy leather with light yellow color

Myrobalan

Myrobalan fruit produce ___ leather and what color

spongy, light yellow

(Fruit)

• Comes from dried, twisted seed pods

• contains high tannin (40-50%)

Divi divi fruit

comes from the sun-dried acorn cups of turkish oak (fruit)

Valonia

Give the 2 Roots (source of Tanning materials)

1. Canaigre

2. Palmetto

(Roots)

• Tanner’s dock, extensively cultivated

• Produce a bright-orange, firm, heavy leather

Canaigre roots

Roots that contains low tannin content (10%)

Palmetto