Summary of basic knowledge of leather

2020-02-17 13:45

1. Definition of leather:

The unprocessed skin that is directly peeled from the animal is called raw skin, and the skin made by various processing techniques is called leather.

2. Types of skin strokes:

Including cows, pigs, sheep, snakes, horses, kangaroos, crocodiles, and other skins, of which cowhide, pigskin, and sheepskin account for 95%.

The anatomy of the dermis:

Four layers of leather

①Grain layer ②Reticular layer ③Tissue layer ④Muscle layer

composition of leather

water

protein

Fat

minerals

other substances

content(%)

64

33

2

0.5

0.5

Fourth, the characteristics of various leather materials

Fetal cowhide: The leather surface is finely spun with beaded grain, and the hand feels soft and elastic. The suede leather has a particularly soft hand. There are growth marks for males, and high-grade uppers for women.

Calfskin: The beading on the leather surface is slightly rough, with obvious growth marks, strong pulling force, good elasticity, and good hand feeling. It is mostly used for men's and women's high-end shoes.

Children's leather: slightly rougher than calfskin, the leather fibers are slightly loose, and the elongation is very high. Men's B-grade shoes

Cowhide: The leather surface is rough and flawed, and it is cheap for men.

Lambskin: The leather surface is firm, the strength is enough, the pores and the bead pattern are regular, and it is used for beautiful women's high-end shoes or dress shoes.

Goat leather: The larger the leather surface, the less detailed the bead pattern is, and it can be rubbed into a round bead pattern surface, women's B-level shoes.

Snake skin: The embroidery is very special, the leather is thin, but it is uncomfortable to wear.

Horse leather: loose leather, rough leather surface, finer buttocks leather, used for men's running shoes.

Kangaroo Leather: Durable, soft, similar to children's leather, for men's and women's shoes.

With its unique naturalness, breathability, and flexure, leather is used in furniture, shoemaking, clothing, and handbags in a wide range of life, which cannot be replaced by any other chemical products. Dongguan Leather Factory

Fifth, the identification of leather?

1. The texture of the leather is natural and inconsistent (the texture of PU and PVC leather is consistent)

2. It feels fleshy (skin feel) astringent, while artificial leather feels smooth

3. Leather smells like an animal, while artificial leather is a chemical smell

4. Burning the leather with fire has a burnt smell of fat burning, and the artificial leather has a green flame and liquefies after burning, and the smell is pungent

5. Look at the cut surface, the dermis has fibrous tissue, and the artificial leather generally has small pores foaming chemical raw materials on the cut surface.

6. Concealment of raw hides

(mainly beef tendon, blood vessel lines, scratches, knife wounds, wind nails, horsefly eyes, pinholes, loose surfaces, cracked surfaces)

1

Injury due to survival

A. Stab wounds: stab wounds from wire wind and tree thorns or injuries from gladiatorial fights?

B. Branding: use hot iron and sulfuric acid to make a seal?

C. Insect spots: damage from slaughtering scars left by pests, bulls and snakes that bite the surface of the cowhide.

D. Knife injury, fibrous tissue damage during slaughter

E. Blood vessels: insufficient bloodletting during slaughter

F. Peeling: lacerations caused by excessive elongation of the peeling machine

2

damage in preservation

A. Salt spot: uneven staining due to the formation of phosphate

B. Corruption: the bead surface or fiber is in a state of corrosion and decomposition

C. Cracks: If the skin is stored for too long, the skin will be too dry and the bead surface will burst.

7. Categories of finished leather

①Bead surface: bead surface skin, grinding surface pattern, nut skin

②Pearl leather: Preserve natural and excellent uppers, which can be embossed to change the appearance with different styles of cattle and cattle species and growth process.

③ Grinding surface texture: poor bead surface, use sandpaper to polish the flaws to improve the usage rate, and can be embossed or flat

④Lump skin: the fiber layer after the dough skin is removed, the anti-hairy skin or the coating becomes the paint skin, that is, the wet or PU skin or the dry PU skin after PU molding is attached.

Eight, leather inspection specifications

Leather grade: inspection and grading according to the usage rate, combined with shoe type, guest acceptance, strength, leather material, and size, usually divided into five grades

Grade A: above 85%

Grade B: 75%-85%

Class C: 65%-75%

Class D: 55%-65%

Class E: 55% or less

Generally, the domestic leather material is increased by 5 percentage points, that is, the A grade is above 90% - the E grade is below 60%.

Daqin Leather Factory mainly produces and processes various types of leather, imitation leather, fabrics, multi-functional manuals/notebooks/calendars/managers/address books/voice folders/briefcases/key bags/document bags/etc. cultural and educational products and business leather product. The company adheres to the principle of "honesty, high quality and competitive price". Sincerely welcome customers at home and abroad to negotiate business with the power plant and create a better tomorrow!

First, the definition of leather:

The unprocessed hide is directly peeled from the animal, which is called raw hide, and the hide made by various processing techniques is called leather.

2. Types of skin strokes:

Including cows, pigs, sheep, snakes, horses, kangaroos, crocodiles, and other skins, of which cowhide, pigskin, and sheepskin account for 95%.

The anatomy of the dermis:

Four layers of leather

①Grain layer ②Reticular layer ③Tissue layer ④Muscle layer

composition of leather

water

protein

Fat

minerals

other substances

content(%)

64

33

2

0.5

0.5

Fourth, the characteristics of various leather materials

Fetal cowhide: The leather surface is finely spun with beaded grain, and the hand feels soft and elastic. The suede leather has a particularly soft hand. There are growth marks for males, and high-grade uppers for women.

Calfskin: The beading on the leather surface is slightly rough, with obvious growth marks, strong pulling force, good elasticity, and good hand feeling. It is mostly used for men's and women's high-end shoes.

Children's leather: slightly rougher than calfskin, the leather fibers are slightly loose, and the elongation is very high. Men's B-grade shoes

Large cowhide: rough leather with many imperfections, cheap shoes for men.

Lambskin: strong leather surface, sufficient strength, regular pores and bead patterns, beautiful women's high-end shoes or dress shoes.

Goat leather: The larger the leather surface, the less detailed the bead pattern is, and it can be rubbed into a round bead pattern surface, women's B-level shoes.

Snake skin: The embroidery is very special, the leather is thin, but it is not comfortable to wear.

Horse leather: loose leather, rough leather surface, finer buttocks leather, used for men's running shoes.

Kangaroo Leather: Durable, soft, similar to children's leather, for men's and women's shoes.

With its unique naturalness, breathability, and flexural properties, leather is used in furniture, shoemaking, clothing, and handbags in a wide range of life, which cannot be replaced by any other chemical products.

Fifth, the identification of leather?

1. The texture of the leather is natural and inconsistent (the texture of PU and PVC leather is consistent)

2. It feels fleshy (skin feel) astringent, while artificial leather feels smooth

3. Leather smells like an animal, while artificial leather is a chemical smell

4. Burning the leather with fire has a burnt smell of fat burning, and the artificial leather has a green flame and liquefies after burning, and the smell is pungent

5. Look at the cut surface, the dermis has fibrous tissue, and the artificial leather generally has small pores foaming chemical raw materials on the cut surface.

6. Concealment of raw hides

(mainly beef tendon, blood vessel lines, scratches, knife wounds, wind nails, horsefly eyes, pinholes, loose surfaces, cracked surfaces)

1

Injury due to survival

A. Stab wounds: stab wounds from wire wind and tree thorns or injuries from gladiatorial fights?

B. Branding: use hot iron and sulfuric acid to make a seal?

C. Insect spots: damage from slaughtering scars left by pests, bulls and snakes biting the surface of the cowhide.

D. Knives, fibrous tissue damage during slaughter

E. Blood vessels: insufficient bloodletting during slaughter

F. Peeling: lacerations caused by excessive elongation of the peeling machine

2

damage in preservation

A. Salt spot: uneven staining due to the formation of phosphate

B. Corruption: the bead surface or fiber is in a state of corrosion and decomposition

C, laceration: if stored for too long, the skin will be too dry and the bead surface will burst

7. Categories of finished leather

①Bead surface: bead surface skin, grinding surface pattern, nut skin

②Pearl leather: Preserve natural and excellent uppers, which can be embossed to change the appearance with different styles of cattle and cattle species and growth process.

3. Grinding surface pattern: poor bead surface, use sandpaper to polish the defect to improve the usage rate, and can do embossing or flat surface

4. Leather: the fiber layer after the dough is removed, the anti-hair leather or the coating becomes the coating leather, that is, the wet or PU leather or the dry PU leather after PU moulding

Eight, leather inspection specifications

Leather grade: inspection and grading according to the usage rate, combined with shoe type, guest acceptance, strength, leather material, and size, usually divided into five grades

Grade A: above 85%

Class B: 75%-85%

Class C: 65%-75%

Class D: 55%-65%

Class E: 55% or less

Generally, the domestic leather material is increased by 5 percentage points, that is, the A grade is above 90% - the E grade is below 60%.