Fur Processing Technologies

The Ministry of Science and Higher Education of the Russian Federation Kazan National Research Technological University








            G. Lutfullina, V. Sysoev, E. Valeeva


FUR PROCESSING TECHNOLOGIES


            Tutorial







Kazan
KNRTU Press
2021

         UDC 675.6(075)




Published by the decision of the Editorial Review Board of the Kazan National Research Technological University


Reviewers:
Cand. Sc. (Technology) D. Semenov Cand. Sc. (Philology) G. Mullakhmetova









         Lutfullina G.
         Fur Processing Technologies : tutorial / G. Lutfullina, V. Sysoev, E. Valeeva; The Ministry of Education and Science of the Russian Federation, Kazan National Research Technological University. - Kazan : KNRTU Press, 2021. - 80 p.

         ISBN 978-5-7882-3080-1

       This study guide describes technologies of fur processing, the principles of raw materials selection, types of technological processes and operations, and their parameters and equipment.
       The study guide is intended for practical classes and lectures for training Bachelor’s degree students majoring in Technologies of Textile Industry. The study guide can also be used for Doctoral and Master’s degree students conducting their research in the field of fur and leather processing.
       It has been created at the Department of Plasma Chemistry and Nanotechnology of High Molecular Materials.


UDC 675.6(075)


ISBN 978-5-7882-3080-1     © G. Lutfullina, V. Sysoev, E. Valeeva, 2021
                            © Kazan National Research Technological
University, 2021

CONTENTS


INTRODUCTION..................................................4
1. FUR PROCESSING TECHNOLOGIES.
MAIN PRINCIPLES ............................................. 7
  1.1. Classification of fur products and raw materials.......7
  1.2. Properties of fur raw materials .......................8
  1.3. Properties of semi-finished fur products .......................9
  1.4. Types of technological processes .................... 12
  1.5. Technological process parameters..................... 14
  1.6. Technological operations of fur processing .......... 16
    1.6.1. Preliminary processes and operations ............ 16
    1.6.2. Fur dressing .....................................22
    1.6.3. Dyeing operations ................................31
    1.6.4. Dyeing of fur velour .............................48
2. CHEMICALS FOR FUR AND LEATHER PROCESSING ................ 50
  2.1. Joseph H Lowenstein & Sons Inc Products ..............50
  2.2. Pulkra Chemical Products .............................55
  2.3. Chemical Products of Russian Research Institute of Fur Industry.62
3. ENGLISH-RUSSIAN DICTIONARY................................66
REFERENCES .................................................. 77

3

                INTRODUCTION





     The study guide focuses on the fur processing technologies including preliminary preparation, dressing, dyeing and finishing prosseses for manu-factiring various fur raw materials. The study guide presents the main characteristics of semi-finished fur products and the main process prameters of their manufacture. It is intended for Bachelor’s degree program "Technologies of Textile Industry".
     The fur industry processes fur and sheepskin raw materials and manufactures various fur and fur coat products.
     Historically, Russia possesses enormous fur resources. Therefore, our ancestors revered furs and believed that they were one of the indicators of wellbeing. In the past, furs were used as money. The names of some banknotes came from the names of some parts of the skins. In ancient Novgorod, a dime was called as the scruff of the neck of an animal (hryvvenik in Russia).
     Skins of marten, sable, ermine, beaver, leopard, fox, and squirrel were the most popular furs in Russia. The common people wore clothes made of goat skins and sheepskins. Craftsmen passed on fur dressing methods and skills from generation to generation as professional secrets. Therefore, the fur manufacturing technologies, which were used by our ancestors, have not been completely preserved. Starting from the 17th century, the processing methods for various types of furs and fur raw materials were described in more or less detail.
     The processing of skins was carried out according to the following scheme. The skin was soaked in a river or in a pond for 6-12 hours, fleshed with a blunt scythe and fermented in vats for 6-7 days. The fermentive solution was made from water, flour and salt. After the fermentation, the skins were hung out on poles to dry in the summer or to freeze the moisture in the winter. Sheepskins were crumpled with an iron hook and combed with a sharp iron comb. Finally, their flesh sides were rubbed with calcined gypsum.
     To carry out the tanning process, the skins were folded in rows with the hair down, covered with oak bark, poured with fermentive solution and left under the load for a week. The procedure was repeated 2-3 times, after which the skins were dried and curried. The removal of grease was carried out with clay and gypsum.
     Fur skins were not tanned. They are tumbled with feet. The fur side was cleaned using flour. In Russia, the furs of such animals as white hare,

4

squirrel, marten, and sable were curried with high quality. For example, the Germans gave squirrel skins for currying in the Russian town of Slobodskoy. However, finishing and dyeing processes were not well developed in Russia. Russian furs were famous for their extraordinary beauty, so little attention was paid to their finishing decoration.
     The first attempt at dyeing fur in Russia dates back to the second half of the 17th century, when the skins were smoked or rubbed with soot to obtain a darker color. Then the fur was dyed using vegetables dyes. A great achievement of the first half of the 19th century was the dipping treatment of skins in a solution of dyes and mordants. In the 60s of the 19th century, campesh and turmeric were used as dyes.
     Until the 80s of the 19th century, the fur dyeing was handicraft. Later, manufactories were opened in Moscow and St. Petersburg. In 1899, a fur factory was founded in the town of Slobodskoy.
     A significant transformation of Russian fur factories began in the 1920s. Large fur factories were reconstructed and built in Moscow, Kazan, Leningrad, Kharkov, Kirov, etc. Central Research Laboratory was established. In 1943, it was transformed into Russian Research Institute of Fur Industry. The technology of skin processing was improved. Fur factories were equipped with new equipment.
     During the Great Patriotic War (1941-1945), the fur industry provided the Soviet army with warm clothing. In the post-war years, a number of large fur factories were built in Moscow, Baltsy (Moldova) and Kaunas (Lithuania). Many factories were reconstructed. The volune of processing of various types of raw materials (skins of mink, blue fox, silver-black fox, rabbit, astrakhan, and sheepskin) increased due to the rapid development of agriculture and fur farming. The technologies for finishing and decorating fur sheepskins were developed. They led to the improvement of quality and appearance of products, as well as the finished product range was expanded.
     Nowadays, the fur industry aims at reorganizing and improving the manufacture of fur products and developing new industrial technologies. Therefore, the main technological tasks of the fur industry are:
     •  creation of multilevel modular manufacture for the commercial processing of raw materials using advanced technologies;
     •  use of efficient equipment and high-quality chemical materials;
     •  introduction of process automation in the preparation of working solutions and automated control of process parameters (temperature, float ratio, concentration, pH, etc.).

5

     The solution of these tasks is one of the priorities of the fur industry due to its high share of the cost of fur semi-finished products (up to 70 %) in the production cost.
     In addition, the fur industry aims at increasing the environmental safety of fur processing. The fur factories use a huge amount of running water, which is usually discharged into nearby rivers after passing through the production cycle. Futhermore, the creation and application of waste-free technologies and the reuse of fur production waste are the important tasks of the fur industry.

6

                1.     FUR PROCESSING TECHNOLOGIES. MAIN PRINCIPLES




    1.1.   Classification of fur products and raw materials


     Fur products are devided into:
     • raw materials (fur and sheepskin);
     • semi-finished products (fur and sheepskin);
     • finished fur products.
     Fur products are the products of furrier factories. We will consider the first two groups (raw materials and semi-finished products) which are processed and dyed at the factories.
     Fur raw materials are classified as:
     1. Fur raw materials:
     -  winter type;
     -  spring type.
     2. Furskin raw materials:
     -  winter type;
     -  spring type.
     3. Furskins of sea animals.
     4. Sheepskins.
     Fur semi-finished products are devided into:
     1) astrakhan fur;
     2) lambskins;
     3) sheepskins;
     4) woolskins;
     5) fur skins of sea animals;
     7) fur plates, furs and fur trims.
     Fur raw materials are skins of wild and domestic animals with high quality of the hair and leather, which are suitable for manufacturing various fur products.
     Fur semi-finished products are processed and sometimes dyed and cut.



7

    Fur skins are unmanufactured hides or skins of fur-bearing animals, which are hunted or bred in fur farms. According to the season of hunting fur skins are subdivided into raw materials of winter and spring types.






    1.2. Properties of fur raw materials



     The quality of the skin is characterized by the following properties:
     •  thickness and uniformity;
     •  area size;
     •  weight;
     •  density;
     •  thickness of the epidermis and subcutaneous tissue;
     •  degree of development of the hair;
     •  ratio of papillary and reticular layers of the dermis;
     •  plexus of fibers in the dermis;
     •  degree of development of topographic areas;
     •  chemical and protein composition;
     •  defects.
     These properties depend on the method of skin processing. The nature of the fur skin is one of the most important characteristics for determining the quality of raw materials.
     For different types of fur raw materials, the thickness and strength of the skin vary significantly for different topographic areas. Typically, the most resisting part of the skin is the animal backbone.
     The skin area may vary in a wide range from 100 to 20,000 cm².
     The skin weight also varies significantly depending on the type of raw materials.
     The skin density determines the duration of skin processing. The rate of diffusion of various substances affects the tensile strength of the skins.
     The degree of development of the hair affects the dermis yield. The more developed the skin hair, the lower the yield of the dermis, since the weight of raw material includes the weight of wool. The more hair on the skin, the less the strength of the papillary layer of the dermis. The degree

8

of development of skin hair and its density determine the heat saving and wear resistance properties of the fur. The nature of the fur skin and its strength characteristics are of importance for assessing the quality of fur raw materials.
     The thickness of the subcutaneous tissue varies greatly depending on the nature of raw materials. The share of subcutaneous tissue accounts for 10-25 % of the mass of skins. The smaller the thickness of the subcutaneous tissue, the greater the yield of finished products, and the less the waste.
     The ratio of the papillary and reticular layers of the dermis affects its properties. The papillary layer can make up 20-70 % of the thickness of the entire dermis. Generally, the reticular layer determines the tensile strength of fur raw materials. The papillary layer mainly determines the softness of fur skins.
     The chemical composition of skins has a great influence on their properties. The most important components of fur skins are proteins: collagen and keratin. The content of other constituents (water, fats) varies from 70 % to 75 %, which affects the relative content of proteins.
     The defects affect the quality of fur raw materials. The more the defects, the more they affect the quality of topographic areas of the skin, and the worse its quality.
     The properties that characterize the quality of raw materials may change under the influence of some factors, such as the origin and living conditions of an animal; slaughtering methods; primary processing; storage conditions.






    1.3. Properties of semi-finished fur products



     The main properties of semi-finished fur products correspond to consumer, sanitary and hygienic requirements.
     The main consumer properties of semi-finished fur products are:
     •  beauty;
     •  strength,
     •  wear-resistance,
     •  heat protection.

9

     The beauty of a fur coat depends on the shine, softness, fluffiness, height, color and friability of the hair. The wear resistance of the fur is determined by the strength of the bond between the hair and the skin and the strength of the hair itself.
     Sanitary and hygienic properties of semi-finished fur products are characterized by their ability to pass air, not to interfere with the removal of sweat, resistance to moisture. Fur and sheepskin semi-finished products are good heat accumulators due to the hair structure and skin microstructure. It characterizes heat saving properties of final products.
     The most common defects of a fur semi-finished product are those that are not corrected or removed during the processing of raw materials. Defects may form during the processes of cutting, milling, washing, dyeing and bleaching of the skins. Defects are evaluated either in linear units of measurement or in units of area, or in pieces.
     The properties of a semi-finished fur product combine the properties of the hair and fur skin as a whole.
     The properties of the hair are:
       •  height (length);
       •  density;
       •  softness;
       •  strength;
       •  crease;
       •  elasticity;
       •  felting;
       •  color and color fastness;
       •  soiling;
       •  gloss.
     The quality of fur skins is characterized by the following properties:
     •    thickness;
     •    strength of the face layer;
     •    seam strength;
     •    plasticity;
     •    ductility;
     •    elongation;
     •    wetness;
     •    shrinkage temperature;

10

     •  chemical composition (mass fraction of moisture, fat, ash, chromium salts, acidity).
     The combination of hair and skin properties chatacterizes the performance properties of fur skins. They are determined by heat saving, waterproof and wearproof properties as well as by skin size and weight.
     The hair ability to hold air (heat protective properties) depends on the hair structure, density, and the degree of hair compression during the wearing of a finished product. The best heat protective properties have the skins of polar fox, beaver, fox, reindeer, fur sheepskin. Skins with rare and low hair (barn rat, calyx, foal, ground squirrel) have low heat-saving properties.
     The wear resistance of the fur depends on the strength of the hair and its connection with the dermis, fragility, abrasion, felting and lightfastness of the color, the methods of skin processing, the thickness and density of the topographic areas.
     The weight of the skin depends on its size, the thickness and density of the fur skin, the density and length of the hair, the hunting period and the habitat of animals, the methods of dressing and dyeing the skin. The weight of fur has a great influence on the ergonomic properties of semi-finished and final fur products.
     The quality of a fur semi-finished product is assessed by the following methods:
     •  organoleptical analysis (Table 1);
     •  wear-testing;
     •  instrumental methods.


Table 1. Organoleptical analysis of fur semi-finished products

                          Maximum, Acceptable limits of
        Indicator          points   quality assessment 
                                     decrease, points  
Hair dressing quality        16            2-3         
Hair color                   10             1          
Fur skin dressing quality    14            2-4         
Total                        40            2-8         

     Instrumental (laboratory) methods of quality assessment include microscopic, chemical, physicochemical analysis. Instrumental methods are used

11