Добавил:
ivanov666
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Processing Techniques for Different Furs. Tutorial
.pdf
21
in these categories. Sheepskins with uniform thin hair have a staple structure,
with semi-fine hair – a staple or staple-braided structure, with a mixed hair –
a braid structure.
A bundle of homogeneous wool, interconnected by grease into larger
bundles is called staple. The fibers consist of one fluff and have a high uniformity in fineness and equalization in length, as well as normal crimp. This
staple shape is typical for fine-wool sheep.
The staple-braided structure is related to fur of mestizo animals. It consists mainly of thick, uniform downy hair, penetrated with sparse transitional
and guard hairs, forming a plait protruding above the downy hair. This fur
structure ia typical for semi-coarse-wool breeds od sheep.
A braid structure is typical for sheep of coarse-wooled breeds (Russian
and steppe). Braids consist of downy, transitional and guard hairs. The transitional and guard hairs protrude high above the downy ones, forming
slightly wavy or straight coarse braids with dead hair.
The fineness is the diameter of the wool fibers in micrometers. This term
is used to characterize the thickness of the hair. Wool fineness (quality) depends on the sheep breed, age, sex, topographic areas, as well as on the feeding conditions of the animals.
Preliminary processing. Sheepskins should be removed in a layer by
a longitudinal incision along the midline of the chest and abdomen to
the base of the tail saving the entire area of the sheepskin from the front legs
to the wrist joint, and from the hind legs to the hock joint. Then, they are
cleaned from blood, dirt, meat and lard cuts and straightened, but not
stretched. They are preserved by wet-salted, acid-salt, dry-salted or fresh-dry
methods. Fresh drying and freezing of sheepskins are not allowed. Sheepskins should be frozen by a wet-salted method at the procurement station.
There are various defects of sheepskins. Fur sheepskins and sheepskins
are sorted according to GOST 28509-90. Sheepskins are classified acoording
to their purpose (fur and fur coat) and theiry type (fine-wooled, semi-finewooled, semi-coarse-wooled, coarse-wooled Russian and steppe, Romanov).
The area of the sheepskin is determined by multiplying the length (from
the upper edge of the neck to the base of the tail) by the width, measured
along a line located 3–4 cm below the front flanks. For sheepskins and fur
sheepskins, except for Romanovskaya, the standard establishes a minimum
area of 24 dm
animals – 35 dm
2
; for Romanov lamb skins: 25 dm2, for Romanov skins of adult
2
.
The method of preserving raw materials greatly influences the skin area.
For example, the acid-salt method causes a higher shrinkage of the skins
22
compared to wet-salted. Dry-salted and fresh-dry methods lead to greater
skin shrinkage. Therefore, the standard provides for coefficients that determine the ratio of the area of sheepskins of various conservation methods to
the area of paired skins.
Depending on the length of the hair, sheepskins are divided into wool,
semi-wool and low-wool. The type of sheepskins is determined depending
on the number of defects and their location.
The sheepskins conserved by the fresh-dry method are smoked. They
are used for everyday life. Sheepskins that do not meet the requirements of
grade IV, fur sheepskins with a wool length of less than 1 cm, sparse-haired
skins with hair slipping (more than 50 % of area) refer to non-standard. Defects of fur sheepskins are indicated in units.
The structure of sheepskins is characterized by the presence of a thin
epidermis, which occupies 1.8–2.5 % of the skin thickness. Skin grain has
uniformly dispersed small pores and a fairly smooth surface. The dermis is
clearly divided into papillary and reticular layers. The thickness of the papillary layer is greater than the thickness of the reticular layer. In coarse-wooled
sheep, due to the deeper deposition of hair, the papillary layer is 70–80 % of
the dermis thickness, in fine-wooled sheep – about 50 %. The papillary layer
is very loose due to the abundance of hair follicles, sebaceous and sweat
glands and muscles that raise the hair. The skins of young animals have
the papillary layer which is more developed than in the skins of adult animals. Collagen fibers of the dermis are arranged in a loop. The reticular layer
is characterized by the fineness of collagen bundles, which are less dense
than in the skins of other animals, and has the horizontal character of the ligature, as well as a significant amount of fat, which weakens the strength of
the ligature. Fat is often located at the border of the papillary and reticular
layers. Therefore, its removal, during the operations of dressing, weakens
the connection between the layers.
The fur of sheepskins consists of thin, thick, and curly hair. Typically,
it is white. Sheepskins contain a large amount of fatty deposits (grease).
Therefore, special attention should be paid to the processes of degreasing and
finishing of sheepskins.
Sorting. Sheepskin batches are sorted according to the followingcharacteristics:
1) Type – sheepskins (fine-wool, semi-fine-wool, semi-coarse); fur
sheepskins (Romanov, Russian, steppe, Mongolian).
23
2) Wool height:
• wool sheepskins with a height of the hair from 30 to 50 mm, from 50
to 70 mm, from 70 to 90 mm
;
• semi-woolen sheepskins with a hair height from 10 to 30 mm;
• short-woolen.
3) Method of conservation: wet-salted, acid-salt, dry-salted, fresh-dry;
4) Color: white and other colors;
5) Size: sheepskins with an area of 24 to 35 dm
2
, from 36 to 60 dm2,
from 61 to 90 dm2, more than 90 dm2;
6) Grade groups: sheepskins of I, II, III grades; sheepskins of IV grade
sheepskins with a lot of defects are assembled in separate batches and processed using a special technology;
7) Imitation of sheepskins: with upgrading the hair, without upgrading
the hair, without upgrading the hair and manufacturing in unpainted form;
8) For manufacturing fur products with specially processed hair, sheepskins of I, II, and III grades are selected. Such defects as shallow burr, slight
bulk, incorrect cut, holes, lard and meat cut are allowed. Fine-wooled sheepskins preserved by of fresh-dry method, as well as sheepskins with skin delamination are not allowed;
9) For manufacturing sheepskins of simple fur processing, the grade
of II, III, and IV, thin-haired, with "stunted" and "wadded" hair, fine-wooled
sheepskins after the dry method of preservation, and sheepskins with skin
delamination are used;
10) For manufacturing rough sheepskins, semi-coarse, semi-woolen
sheepskins with the inhomogeneous fur hair of a braid-like structure and medium density, with a hair height of 30–40 mm are used.
Sheepskins selected for a production batch are sent to the following operations of demanuring such as removing heads, paws, tails and other nonprocessing areas of sheepskins, and cutting tags.
The area of each sheepskin is measured in dm
2
according to the GOST
28509-90 developed for undressed sheepskins. Then, the weight of the production batch is determined. According to the weight and area, the size of
the production batch and the equipment load rate are set. The capacity of
the equipment and the value of float rate are also taken into account.
Fur sheepskins
Application. Sheepskins are sheared, dyed, combed. Manufactures im-
itate valuable types of furs such as otter, beaver, fur seal, nutria, mink, tiger,
leopard, etc. Headdresses, collars, children and women fur coats are made
;
s
24
from fur sheepskins. Sheepskins are produced in sheared form, undyed, dyed,
ordinary or special processed, with artificial curls and velor.
The height of the sheared sheepskin hair depends on the applications:
hats – from 10 to 14 mm; outer fur clothing – from 14 to 20 mm; imitating
broadtail lamb – from 6 to 8 mm.
Sheepskins are divided according to the method of dyeing: monochromatic dyeing, airbrushed dyeing (dark hair on a light background), printing
dyeing, hair ends dyeing (with white, brown, black hair ends), photographic
film printing.
Fur sheepskins of special processing are the most valuable. They differ
from sheepskins of simple processing by increased sheen, good smoothness,
and friable hair that does not change shine under the influence of moisture.
Sorting. According to GOST 4661-76, sheepskins are sorted into
dressed unpainted, dyed, rough, sheared, simple and special processed sheepskins.
By the nature of the fur, sheepskins are classified as:
• fine-fleece sheepskins with homogeneous soft silky hair, consisting
of downy hair, the fineness of which does not exceed 25 microns;
• semi-fine wool sheepskins with less homogeneous and softer ha
ir,
consisting of coarser hair with a fineness of 25.1–31.0 µm;
• semi-coarse sheepskins with heterogeneous hair, including semi-
coarse smooth patterns, consisting mainly of guard hair.
By the hair color, sheepskins are divided into monochrome sheepskins;
dyed and multi-tone sheepskins; sheepskins with different patterns.
By the type of processing, sheepskins are sorted as specially and typically processed.
By the skin size, sheepskins are classified in the same way as raw materials.
There are several grades of fur sheepskin:
• I grade – sheepskins with thick hair on the main area and denser hair
on the bottom parts;
• II grade – sheepskins with denser hair, especially on the bottom
and
side parts.
Depending on the number and size of defects, sheepskins are divided
into five groups.
In terms of chemical composition and indicators of physical and mechanical properties, sheepskins should comply with the following standards.
25
Skin surface:
Shrinkage temperature
> 70 ºС
Mass fraction
moisture
< 14 %
chromium oxide (chrome tanned sheepskins)
0.8–1.8 %
ash
< 8.0 %
substances extracted by organic solvents
10–20 %
pH of the aqueous extract
4.0–7.5
Tensile strength
sheepskins with an area of more than 40 dm2 (manufactured according to the Government contract)
> 9.8 MPa
sheepskins with an area of 40 dm2 and less than 40 dm2
> 5.9 MPa
Full elongation for a sheepskin at a stress of 4.9 MPa
< 30.0 %
Mass fraction of substances extracted by organic solvents
< 2.0 %
Color fastness to dry friction
for black dyed sheepskins
< 3 points
for colored sheepskins
< 2 points
Fur hair surface:
Marking. A certain sequence of digital designations should be applied
on the surface of sheepskins. O stands for snuffed sheepskins. According to
the type of sheepskins: fine-fleece – 1, semi-fine-fleece – 2, semi-coarse – 3.
According to the sheepskin grade: the first grade – 1, the second grade – 2.
According to the defect group: the first group – 1, the second group – 2,
the third group – 3, the fourth group – 4, the fifth group – 5. The area of
sheepskins is indicated in dm
2
.
Wool sheepskins
Application. Wool sheepskins are used to manufacture outerwear, hats
and mittens. Wool sheepskins are produced in undyed, dyed (black, brown,
blue and other colors) forms, and finished with latex film formers. The skin
surface should be well tanned. The quality of the tanning process is determined by the penetration depth of a tanning agent (penetration level).
The penetration level of chrome tanned and sulphite-cellulose tanned sheepskins should be at least ⅓ of the skin thickness. The sheepskins should be
dyed uniformly, without spots and glossy stripes, soft, non-greasy to
the touch. The sheepskins should be elastic, non-sticky, and resistant to dry
26
friction, uniformly colored over the entire area, without cracks and peeling
during stretching.
Sorting. The quality of dressed wool sheepskins is evaluated in accord-
ance with GOST 1821-75. Depending on the quality of the hair, the wool
sheepskins are divided into three types: Romanov, Russian, and steppe. Romanov sheepskins are subdivided into groups. Romanov felt sheepskins of
st
the 1
group, Romanov adult sheepskins of adult animals of the 1st and
nd
2
groups. Romanov felt sheepskins produced from young animals at
the age of 5–8 months refer to the group of the best quality.
Wool sheepskins are sorted into four grades (I, II, III, IV). Surface dyed
sheepskins are divided into three grades (I, II, III). The variety of wool sheepskins is determined by the number, size and location of defects. Defects are
characterized according to their length in dm (tears, crowbars, deep undercuts – more than ⅓ of the thickness) and their area in dm
2
(holes, bald
patches, sores, skinny patches, not overgrown pockmarks, slipping hair,
moleheads, pockmarks, bumps, fat spots, uneven color, aromas, fragrance,
deep undercuts, etc.).
Wool sheepskin processing technology. The main technological oper-
ations for wool sheepskin processing are: soaking, hair degreasing, fleshing,
hair cutting, pickling, and tanning.
The duration of the processing cycle should not exceed:
• sheepskins with thick skin, which are sent to the finishing operations,
are processed for 20 calendar days;
• sheepskins with dressed fur hair are processed for 17–19 calendar
days;
• sheepskins without finishing processing are processed for 12 calen-
dar days;
• undyed sheepskins are processed for 9 calendar days.
The batch size, equipment loading rate, and the amount of chemical materials are evaluated in accordance with a reference weight of sheepskins
(Table 1). Table 1 presents the conversion factors which are used to determine the weight of sheepskins in terms of the weight of freshly dry raw materials.
Wet-salted and acid-salted raw materials are soaked in clean water at
20 ºС for 4 hours. If the wet-salted sheepskins are dried during their storage,
the soaking process is similar to the process used for dry-salted raw materials. However, the duration of their processing may be reduced to 2–4 hours.
27
The parameters of the first soaking process for dry-salted raw materials
Type of
sheepskin
Weight of a sheepskin, kg
Weight of m
2
skin surface after
fleshing
Conversion fac-
tors for fur raw
materilas
Raw materials
sheepskin after tan-
ning
semi-
finished product
fresh-
dried
dry
-
salted
wet-
salted and acid
-
salted
fresh-
dried
dry-
salted
wet-
salted and
acid
-
salted
Fine fleece
3.6
4.5
6.3
2.5
0.85
3.2
1.0
1.25
1.75
Semi-fine
fleece
2.6
3.2
4.5
1.8
0.85
3.2
1.0
1.25
1.75
Semicoarse
2.2
2.8
3.9
1.5
0.72
3.0
1.0
1.25
1.75
are:
• float rate – 10;
• temperature – 25–30 ºС,
• process duration – 16–24 hours.
• The composition of the working solution is prepared according to
the Standards developed for the production of wool sheepskins:
• 40 % formalin – 1.0 cm
3
/dm3;
• sodium fluorosilicate – 1.0 g/dm3;
• sulfanol – 2.0 g/dm
3
.
Table 1. Calculations of batch sizes, equipment loading rates, the amount
of chemical materials in accordance with the sheepskin weight
Then, the second process of soaking is performed at the same values of
the float rate and temperature. This process takes 8 hours. The working solution contains sodium fluorosilicate (0.75 g/dm
If the sheepskins are not placed into the bath fully, the duration of the soaking
process increases.
The soaking process of fresh-dried and dry-salted sheepskins is recommended to conduct in the presence of enzymes. There is a scheme in which
the second soaking is carried out in the presence of enzymes for 8–20 hours
at the pH 5.
3
) and sulfanol (1.0 g/dm3).
28
Preliminary or intermediate processing of raw materials in organic solvents is also recommended to accelerate the process of soaking. Removing
a significant amount of fatty substances from the skin facilitates the penetration of the soaking solution. In addition, it leads to a 4–5-fold decrease in the
process duration.
After soaking, the sheepskins are sammed. The operation of samming
can be carried out by the MMG-1500-M fleshing machine with blunt knives.
Sheepskins are placed on the machine shaft and squeezed out with a constant
flow of clean water (temperature – 20 ºС).
The next process is degreasing. It is carried out in the bath at a float rate
of 7 and a temperature of 42 ºС. The process lasts for 1 hour. The composition of the working solution is: sulfanol (8.0
sodium carbonate (0.5 g/dm
3
). Water is poured into the bath. Then the work-
3
g/dm
); formalin (0.5 g/dm3);
ing solution is added and sheepskins are loaded. The rotation of the bath is
continuous. After 30 minute drainage of the working solution, the second
degreasing is carried out at the same process parameters.
Then, two rinses with clean water are carried out at a temperature of
38 ºС for 30 minutes. Between these two operations, the intermediate drainage (30 minutes) and final drainage (2 hours) are conducted.
Russian Research Institute of Fur Industry has developed the following
technology for wool sheepskin processing using Russian reagents. This technology is used for fresh-dryied or dry-salted raw materials. The float rate is
10 for preliminary processes. Preliminary processes begin with the first hair
soaking at a temperature of 25–30 ºС. The duration of the process is 2–
4 hours. The composition of the bath is: Effect M (1.0 g/dm
(0.5 g/dm
at a temperature of 30 ºС. The process duration is 14-16 hours. Bath composition is: Tetramol (2.0 g/dm
(0.5 g/dm
3
). Then, the skins are sammed and sent to the second hair soaking
3
3
); sodium carbonate (0.3 g/dm3).
); Gamma 1 (2.0 g/dm3); FH preparation
3
); Gamma 1
After hair samming, the entire skin is squeezed out in a centrifuge,
sheared, fleshed and degreased at a temperature of 40–42 ºС for 1–2 hours.
The working composition is: Tetramol (2.0–4.0 g/dm
(0.5 g/dm
3
); 40% formalin (0.5 g/dm3). Then, the skins are washed with clean
3
); sodium carbonate
water for 30 minutes at a temperature of 30 ºС. After that, the skins are sent
to pickling at a float rate of 7.
The process of pickling is carried out at a temperature of 35 ºС for 14–
16 hours. The composition of the bath is: sodium chloride (50.0 g/dm
Gamma 2 (0.5 g/dm
(6.0 g/dm
3
) diluted with water in the ratio of 1 to 5 is added to the bath. This
3
); Mexinol (2.0 g/dm3). After an hour, formic acid
3
);
29
is followed by ageing (24–48 hours), after which the skins are sent for tanning and fattening (temperature 38 ºС, duration 6–8 hours). The composition
of the bath is: sodium chloride (50.0 g/dm
(6.0 g/dm
3
). After an hour, dissolved chrome tanning agent (8.0 g/dm3) is
added to the bath. After an hour, sodium bicarbonate (1.5 g/dm
3
); Gamma 3 (1.0 g/dm3); Mexinol
3
) are added
to the bath in two steps to pH 3.8–3.9. After ageing (12–24 hours), the skins
are sent for samming and sleeking. Then, the process of two-stage drying is
carried out. Further processing is carried out according to the proposed technology.
Then, the process of drumming is carried out for 3.5–4 hours using
3
30 cm
of Gamma 7 per sheepskin and 10 cm3 of Antistatic M per sheepskin.
Further processing is carried out according to the proposed technology.
The sheepskin hair is cleaned according to the technology using:
Polyfix – 50 cm
300 cm
3
.
3
/dm3; formic acid – 75 cm3/dm3; 95 % ethyl alcohol –
Pulkra (Boehme) has developed the technology for fresh-dried sheepskin processing. The float rate is 10 for preliminary and dressing processes.
The first soaking takes place at a temperature of 25 ºС for 10–14 hours.
The soaking solution contains: Atezana LPV (1.0 g/dm
(2.0 g/dm
3
). According to the proposed technology, the skins sre soaked for
3
); Atezana Ultra
an hour, then they are stirred every hour for 5 minutes.
After that, Further, mechanical washing of the hair is carried out using
"Sabrese" machine. This is followed by samming in a centrifuge, cutting, and
fleshing. Then, the second soaking is carried out at a temperature of 25 ºС
for 10–12 hours. The composition of the bath is: sodium chloride
(10.0 g/dm
(1.0 g/dm
3
); Atezan LPV (1.5 g/dm3); Atezan Ultra (1.0 g/dm3); Foryl PK
3
). After that, the processes of rinsing with clean water, mechanical
rinsing using "Sabrese" machine, samming in a centrifuge, cutting, fleshing,
washing, and degreasing are carried out at a temperature of 38 ºС for 2 hours.
The composition of the bath is: Foryl PK (1.0 g/dm
(1.5 g/dm
sent to pickling, which is carried out at 30 ºС for 14–16 hours. The composition of the bath is: sodium chloride (50.0 g/dm
GLS (2.0 g/dm
3
); sodium carbonate (0.3 g/dm3). Then, the skins are washed and
3
3
); after an hour – 85% formic acid 5.0 (g/dm3).
); after 30 minutes – Pellan
3
); Atezan Ultra
After the process of ageing (12–14 hours), the skins are tanned at 35 ºС
for 14–16 hours. The working solution contains: sodium chloride
(40.0 g/dm
agent (33 % basicity, 5.0 g/dm
(2.0 g/dm
3
); Pellan GLS (2.0 g/dm3). After 30 minutes, chrome tanning
3
) are dosed to the bath in dissolved form. After 3 hours, the second
3
), Pellan GLH (3.0 g/dm3), and Tannit LSV
30
portion of chrome tanning agent (10.0 g/dm3) is added, After 45 minutes,
sodium bicarbonate (1.0 g/dm
three doses every 30 minutes in the amount of 2.0–2.5 g/dm
3
, pH 4) is added. Then,bicarbonate is added in
3
. The pH at
the end of tanning is equal to 3.9.
The next process of washing is carried out at 30 ºС in the presence of:
Foryl LHTs-S/ADL (0.5 g/dm
3
); 60 % acetic acid (0.5 g/dm3). This is followed by ageing for 12–14 hours, drying, moistening, staking, sleeking, cutting, sorting, and degreasing in a dry cleaning machine in the presence of
perchlorethylene or trichlorethylene (2 cm
4 minutes. Then, the processes of drying, moistening, staking, and sleeking
are repeated. The working composition contains 550 cm
of Kutafix RF, 100 cm
3
of alcohol, and 50 cm3 of 85 % formic acid. Sleeking
3
), Tricopon VP (1 dm3) for
3
of water, 300 cm3
is carried out 4-5 times at a temperature of 180 ºС.
The operation of dyeing and greasing are carried out after preliminary
preparation of the semi-finished product. Pulkra (Boehme) has developed
the following technology for hair dyeing using metal complex dyes (float
rate – 10–15). Neutralization as a prelimenary process is performed at a temperature of 40 ºС for 1.5 hours. The composition of the bath is: 25 % ammonia (2.0 g/dm
3
); Foryl PC (0.5 g/dm3). After that, washing and dyeing operations are carried out at 65 ºС with metal complex dyes of the Dorapel M in
the presence of Doregal PEV reagent. The composition of the bath is: formic
acid (0.2 g/dm
15 minutes, Dorapel M (x g/dm
(1.0 g/dm
3
); after 10 minutes, Doregal PEV (1.0 g/dm3) is added; after
3
) is added; after an hour, 85% formic acid (1.0 g/dm3). Finally,
3
) is dosed; after 30 minutes Pellan FSN
the solution is drained out after 30 minutes.
Then, the process of washing is carried out to obtain a transparent solution. After that, the skins are fatliquored at 45 ºС for 2 hours in the presence
of Pellana GLH (3.0 g/dm
3
) and Sirial OFB (3.0 g/dm3). After 1.5 hours,
85 % formic acid is dosed. After 30 minutes, the solution is drained out. This
is followed by washing, samming in a centrifuge, drying, moistening, staking, and steeking. The working solution contains 550 cm
of Kutafix RF, 100 cm
3
of alcohol, 30 cm3 of 85 % formic acid, and 20 cm3
3
of water, 300 cm3
of Softymol L6. Steeking should be carried out 5 times. Skins of light colors
are processed at 160–180 ºС, skins of dark colors are processed at 200 ºС.
Then, the process of drumming is carried out for 2 hours in 100 kg of
coarse sawdust for 150 skins and 3.0 dm
are shaken, combed, and dried at 35 ºС. The the process of sleekingis repeated in 860 cm
3
20 cm
of Glanzlyustr S, and 20 cm3 of Softymol L6. Sleeking should be
3
of water, 50 cm3 of Kutafix RBM, 50 cm3 of alcohol,
3
of Kutafix LGF. Then, the skins
Соседние файлы в предмете [НЕСОРТИРОВАННОЕ]