INTRODUCTION:

The hides and skins of certain animals which has been separated from the fleshy and fatty materials and prepared by means of chemical agents in such a way that it resists the influence to which it is naturally subjected is known as leather. Leather was produced from a variety of hides, kips, and skins.¹ There were generally two ways of tanning process which have different types of tanning agent in the manufacturing of leather; first, vegetable tanning process and second, chemical tanning process.²

Vegetable Tanning Agents:

In this process, the substances used in tanning were the bark, fruit, wood, leaves, and pods of different of plants and trees and shrubs, which has the property of combining with gelatin to form an insoluble impenetrable compound, was another very important raw material for the leather industry.

The various vegetable tanning materials were used in the tanneries of United Provinces were:

1. Babul (Acacia Arabica)

2. Divi-divi (Caesalpinacoriaria)

3. Sumach

4. Dhoara or Balki (AnogeissusLatifolia)

5. Sal (Shorearobusta)

6. Glunt (Ziziphusxylopyra)

7. Myrobolan or Har and Beraira (Terminaliachebula)

8. Banda (the ordinary word for mistletoe)

9. Amaltas (Cassia fistula)

10. Aonla (Phyllanthus Emblica)

11. Avaram (Cassia auriculata)

12. Wattle (Acacia decurrens)

Chemical Tanning Agents:

The substances used in tanning the hides and skins were chemical agents mostly Sodium Dichromate. In consequences, the tanning industry of considerable size had been build up; but on account of the lack of local tan stuff and the presence of an important section of the chemicalindustry, chrome tanning was becoming more important.

Tanning Process or Operation:

Tanning word is derived from the Latin word for oak bark, denoted the process which converted the putrescible animal skin into the leather.³ The tanning industry in India till the 19^th and early 20^th century could be classified as:⁴

· Tanneries producing finished vegetable tanned leather using bag tanning process.

· Tanneries producing vegetable tanned leather using the European methods.

· Tanneries producing chrome tanned leather.

Animal skin is the basis of leather and some knowledge of its intricate structure and complex chemical composition is essential to an appreciation of the extremely complicated reaction involved in making leather.⁵ The skin of ordinary animals is composed of two parts, the epidermis, built up of cells which at the bottom are round and soft, becoming flattered and harder towards the surface and the corium or the true skin consisting of fibres which are loose and coarse at the flesh side and finer and more closely packed towards the surface. The fibres at the grain side are all horizontal, while that lower down lies in all directions. The bundles of fibres are tied together by bands which redissolved in the liming process, allowing these fibres to swell. The fibres then combine with the tannin to form leather.⁶

In United Provinces, during the 19^th and 20^thcentury, mostly the bag tanning process was used by the native tanner. The operation involved in any tanning process could be classified:⁷

· Pre-tanning

· Tanning

· Post-tanning

Pre-Tanning Processes or Operations:

1. Flaying:

When the animals were died or slaughtered as a food. The flayers were flaying the hides or skins from their animal body by the primitive method through a sharp knife.⁸

2. Curing:

Preparing hides or skins begins by currying them with salt. This step of tanning for all kinds of hides involved the removal of the moisture. Since the hide removal from the back of animal was immediately attacked by bacteria. These bacteria which entered the pelt through the flesh side multiplied rapidly eating and pelt substance. It emitted a fluid which patronized the substance into a compound which was easily soluble in water. Since the bacteria did not survive without moisture, to protect the skin, tanner either treated the skin with some compound which the bacteria did not attack or removed all the moisture from the skin. For the latter, a layer of salt was placed between two hides; a number of hides were thus placed in packs and left in the sun for drying.⁹

3. Soaking:

The hides were received dry salted and they were soaked and worked in a stock-drum until they were soft enough for the next process. The main object of this process was to cleanse the salts hides thoroughly of all blood, salt, andother extraneous substances. It was a very important process as it removed the salt, which delayed the liming process.¹⁰ Buffalo hides taken 30-40 hours to soak while cow hides taken 10-20 hours.¹¹

4. Liming:

The washed hides were split into sides and placed in pits containing a mixture of lime, sajji (impure soda) in the proportion of one seer of lime for one hide and one seer of sajjifor every ten seers of lime. The hides remained in the pits for 3 to 8 days depending on the season. Longer liming was necessary for the cold weather.¹²

5. Unhairing:

Lime has the effect of plumping out the shrunken hides, by allowing the fibres to swell and open, and of releasing the hair roots, thereby facilitating unhairing.¹³ These hides were removed and unhaired with a blunt knife khurpi, and placed once again in the pit with a new lime solution of the same strength as before but to which sajjiwas not added. At this stage, great care had to be used in order not to damage the grain of the hides in any way.¹⁴

6. Fleshing:

This process consists of cutting the flesh off the hides with sharp knife specially made for this purpose. There were two methods of doing this work, either European or Indian. With the European method of fleshing very large two-handled knives were used while in Indian method small knives known as rampiwere used. This work was difficult to do and could only be done by trained men.¹⁵

6. Scudding:

This consists of scraping hairs that might be on the hides. It was done over a beam with a blunt knife specially made for this purpose. After the hides had scudded they were carefully selected for the different kinds of work for which they were suited and stamps put on the different classes to distinguish them. They were then weighed one by one and the weight is known as the “lime weight” recorded. After weighing, the hides were bated.¹⁶

7. Deliming:

It consists of the removal of pelt hair by a combination of chemical and mechanical processes. A lime solution again pasted to destroy the hair or attack the hair roots. So, that it would come free of the pelt; the pelts were soaked in the deliming solution again in the paddle vats, which generated a rubbing action to finally remove all the remaining hair on the hides.¹⁷

Tanning Processes or Operations:

1. Bating:

The limed hides which were swollen were unhaired and fleshed on a tanner’s beam, which was a stone slab, using a rampior curriers knife. These fleshed hides were placed in clean water for 4 to 6 hours. This was followed by the next stage of tanning known as bating. The main purpose of the bating was the removal of the lime. The hides for bating were placed in large earthen vessels containing a fermented mixture of tan gharasof very old tan liquor of about 15° and one seer of kan (rice husk). Around four hides were placed in one vessel for about 4 days. Some tanners used water mixed with molasses or powered mahwa flower as bates.¹⁸

2. Suspending:

The hides after bating lay on a slab and scraped on the grain side and then wrung dry. For removing the lime, the butt end of the hide was fixed to the top of a stout immovable stake, the neck was lapped over the middle of a bamboo, about 3 feet long, which was then turned by men at either end like a windless. These were hides were once again rinsed in the old tan liquor, then kneaded, rubbed and wrung dry on the stake again.¹⁹

3. Pickling:

The pickling of a pelt places it in a condition to receive and absorb the actual tanning agent. It was accomplished with a variety of acids, the most common of which was sulfuric acid, mixed with the common salt. This process was a form of preservation in itself and was the final step before the actual tanning.²⁰

Tanning:

1. Tanning of hides:

These hides were sewn up with munj into a bag containing a tan mixture of 15 seers of new and 10 seers of half-spent tannin (disintegrated babul bark), water and weak tan-liquor, another tan mixture consist of 2 or 4 pounds of small banda twigs which were pounded and mixed with water. Banda was sometimes substituted with babul bark, sal bark, and myrobolan. These hides bags filled with one of the above mixtures were suspended by the neck from a wooden tripped over a tree. The liquid which forced through the pores of the hide dripped into the tree below, this was again poured into the bag. After 24 hours, the hide was brought down and neck end was sewn up and the butt opened, the above process was repeated.²¹ The hide was laid out in the final step, each side was sprinkled with four ounces of Khari (impure salt) and four ounces of bark dust which was rubbed into the hide.²² By doing this, Indian tanner forced the tanning agent through the loose hide. In this way, the native tanner, tanned the raw hides and sent them for manufacture.²³

In chrome tanning, this method consisted of soaking the pelt in large revolving drums filled with soluble chromium salts, primarily basis sodium dichromate.²⁴

2. Tanning of skins:

The native tanners adopted different methods for the tanning of skins which rarely used the bag process for skins, while the European tanners employed the same methods for the tanning of hides and skins, only the process in the case of the latter were proportionately shorter and materials used for tanning were smaller in quantities, the principle was essentially the same.

In the United Provinces, the tanning of skins was entirely in the hands of chikuas or chiks, who called themselves Mohammadans. They looked down with scorn on the Chamars who worked in cowhides.²⁵ The skins of goat and sheep were first of all washed and then limed for a day. The liming consisted of simply laying the skins in a mixture ofquicklime and water for 5 to 15 days depending on the season, as in the case of hides, longer liming was necessary for cold weather. The limed skins, which were swollen, were then unhaired and fleshed on a tanner’s beam, which was a stone slab, using a two-handled knife. These skins were then placed in clean water for 4 to 6 hours and then began the next stage of tanning known as bating.²⁶ One consisted of smearing the skin with a thick paste made by boiling down mahva flower, half a pound of marua was used for one skin, which was then kept for 8 days. The skins were later washed and laid in the tan-liquor, which was placed in a mellow tan-liquor, which is one which had already been used several times; the skins were then gradually promoted until they reached the strongest and newest liquor. This process took 8 to 15 days, during which the skins were frequently handled, usually 2 to 3 times in a day. These skins were then wrung out, for the butt end of the skins was fixed to the top of a stout immovable stake, the neck was lapped over the middle of a bamboo about 3 feet long, which was turned by men at each end like a windless. These skins were finally rubbed with sajji (impure soda) and bark dust, forcing the tanning agent through the loose skins. They were finally dried in the sun and were ready for market.²⁷

Post-tanning Processes or Operations:

1. Splitting:

Leather was similar to an ordinary band saw turned on its side that the rapidly splitting blade edge was horizontal. Leather was fed into the splitting tools which according to the thickness of leather into uniformity throughout the entire pelt.²⁸

2. Shaving:

After splitting, the pelt was then fed by saving tools which further adjusted the uniformly the pelt’s thickness.²⁹

3. Dyeing:

Aniline dyes were laid on and scrubbed into the finished leather with a stiff brush. They were obtainable in every bazaar and were very popular. Most European and many native leather dressers used nothing else. The skin was simply stretched on a stone slab and the dye applied to it. The Indian tanners used the word “rangana” to indicate the processes of tanning. They were dyer rather than a preserver. By varying the contents of their hide bags, they could produce different shades of buff; e.g. dhaora gave a light yellow colour, babul buff, sal gave a deep orange-brown colour, one chhatak of copper and eight pieces of myrobolans gave black colour and harsinghar flowers and sappan wood gave red colour leather. These were merely rubbed on to the leather.³⁰

4. Staking:

It was the process of softening the pelt by both pulling and rolling it to made it pliable. Staking governed the final firmness or softness of the pelt.³¹

5. Finishing:

It was the process of applying a thin film of several available finishing substances over the grain surface of the pelt. A finished film enhanced the colour and increased the pelt’s resistance to stain and abrasion.³²

Technical changes in the leather industry during the colonial period:

The native tanners continued using the bag tanning processes for the tanning of hides and skinsuntil the British introduced the western processes of vegetable tanning and currying in 1857. These processes first were introduced in the tanneries established by the govt., which were producing leather for military equipment.³³

The English process consisted of first washing the hides were soaked in the stock drum, which was built of planks, with a space of about two inches between each. The drum revolved in a pit full of water which percolated freely. The inside of the drum was studded with large wooden pins. The hides were stocked here until they were soft enough for the next process. The objectives of soaking and stocking were to soften the hides and remove the salt, as this impeded plumping; the hides were removed from the drum and washed.³⁴

The hides were then placed in pits containing quicklime. These pits were six in number and were of a graduated strength. The strength of the lime solution and duration of process depended upon the class of leather to be produced. It took 10 to 15 days for each hide to pass through each of six pits. Lime had the effect of pumping out the shrunken hides, by allowing the fibres to swell and open, and of releasing the hair roots, which facilitated unhairing. The limed hides were laid over a tanner’s beam which was a coarse block of wood in an almost vertical position. The hairs were scraped off by the beams men with a blunt knife standing over and behind the beam. The unhaired hide was then turned over and fleshed with a sharp two-handled knife, with great skill. At some places in U.P., fleshing machines were also used. At this point, the hide was removed and tanned separately. The lime having served its purpose had to be removed. For this purpose, the hides were bated.³⁵

For bating, the hides were placed in drums revolving in a pit containing a mixture of bran and water. They were remaining in this drum for 4 to 5 hours. Bran in fermentation produced ammonia, which removed the lime from the pores of the pelt cleaning out the filth and foreign matter and also expanding the fibres of the skin in the process. The hides were then laid out on a table and violently scrubbed to remove the released hair and dirt, but the main object of the scrubbing was to extract the fat deposit at the roots of the hair. From here the pelts were taken to the pits for the proper tanning³⁶.

For tanning, the hides were first placed in the “suspenders” or “colouring pits” containing weak and mellow tan-liquor which set the grain and gave colour. The hides were hung up separately on a bamboo lying over the pit, flesh sides in. After 6 days, they were promoted to the ‘floaters’ which the six pits of graduated strength. From here the pelts went into the “dusters” which were it's containing a strong tan-liquor. Some finely ground bark powder was placed between each layer of hides to maintain the strength of the tan-liquor. The hides remained in the floaters and dusters for 3 or 4 months; here they were occasionally handled until they were fit to go into the “layers”. Here they lay for 6 to 8weeksin a strong liquor and layer of fine bark between each pair. Here the hides were not handled while the floaters and dusters were graduated, the layer was not.³⁷

In some tanneries of U.P. drum tanning was introduced at the beginning of 29^th century. The hides were placed in the drum for 48 to 50 hours. This drum tanned leather was suited for ornamental work such as bookbinding. Chrome tanning was also done in a drum with the aid of chemicals.³⁸

While the tanning by native tanners was completed at this stage, in tanneries conducted on European principles, the tanned hides underwent many processes before they were fit for manufacture, First of all, the hides were shaved off of all inequalities, reducing as far as possible the hide to the same thickness throughout. To remove creases, dirt, and bloom (a compound of tannic acid and gelatin), the hide was made wet and scoured by hand with a stone or by a machine which had a rapidly revolving Cogger roller. These were then placed in a revolving drum with sumach mixed with water for 20 minutes, and then half dried. Finally, the hides were set out on a table, flesh side downwards on a layer of dubbing (made from the best of native tallow and cod- oil) and rubbed heavily. These hides were then ‘slacked out’ and given a coat of oil, and allowed to hang for four hours. This process was repeated. The leather was ready for the cutter’s shop.³⁹

CONCLUSION:

Leather is manufactured by the number of the technical process from its raw hides and skins.⁴⁰ Tanning is the process in which hides and skins influenced to change in leather. Colonial govt. has introduced many new technologies or modern processes which were applied in manufacturing leather in this province. Newly started leather factories in United Provinces have applied new tanning processes named finished vegetable tanning using bag tanning process, vegetable tanning using the European methods of tanning and chrome tanned leather. So, it can be said that colonial govt. have taken many steps and introduced many new modern techniques for improvement of the leather industry in this province.

REFERENCES:

1. Sangeeta Bansal, Preeti Sodhi. Pineapple Leaf Fibers: ECO Souvenir. Research J. Humanities and Social Sciences. 5(2): April-June, 2014, 141-147.

2. Aslam Hossain, Sanjay Roy, Partha Sarathi Guin. The Importance of Advance Biomaterials in Modern Technology: A Review. Asian J. Research Chem. 2017; 10(4):441-453.

3. Wilson, J. A. (1928). Chemistry of leather manufacture, p. 1.

4. Sharma, M. (2014).Workers and leather industry in Kanpur (1861-1947): transition from craft to factory production,, p. 52.

5. Wilson, J. A. (1928). Op. Cit., p. 19.

6. Sharma, M. (2014).Op. Cit., p. 52.

7. Ibid.

8. Shrivastava, L. N., (1934). Leather industry, p. 2.

9. Sharma, M. (2014).Op. Cit., p. 53.

10. Walton, H. G. (1903). Op. Cit., p. 7.

11. Martin, J. R. (1903). A Monograph on Tanning and Working in Leather in the Bombay Presidency.Printed at the Government Central Press, p. 9.

12. Sharma, M. (2014). Op. Cit., p. 53.

13. Walton, H. G. (1903). A Monograph on Tanning and Working in Leather in the United Provinces of Agra and Oudh. Government Press, United Provinces, p. 7.

14. Martin, J. R. (1903). A Monograph on Tanning and Working in Leather in the Bombay Presidency.Printed at the Government Central Press, p. 10.

15. Ibid.

16. Ibid.

17. Willcox, D. J. (1969). Modern leather design. Watson-Guptill, p. 6.

18. Sharma, M. (2014).Op. cit., p. 53, Also see, Walton, H. G. (1903). Op. cit., p. 9, &Briggs, G. W. (1920). The Chamars.Association Press.

19. Ibid, Also see, Walton, H. G. (1903). Op. cit., p. 10, &Briggs, G. W. (1920). Op. Cit., pp. 256-257.

20. Willcox, D. J. (1969). Op. Cit., p. 6.

21. Sharma, M. (2014).Op. cit., p. 54, Also see, Briggs, G. W. (1920). Op. Cit., p. 257.

22. Ibid.

23. Ibid

24. Willcox, D. J. (1969). Op. cit., p. 6.

25. Sharma, M. (2014). Op. cit., p. 55, Also see, Briggs, G. W. (1920). Op. Cit.

26. Ibid.

27. Ibid.

28. Willcox, D. J. (1969). Op. Cit., p. 6.

29. Ibid.

30. Walton, H. G. (1903). Op. Cit., pp. 17-18.

31. Willcox, D. J. (1969). Op. Cit., p. 7.

32. Ibid.

33. Sharma, M. (2014). Op. Cit., p. 58, Also see, Briggs, G. W. (1920). Op. Cit.

34. Walton, H. G. (1903). Op. Cit., p. 7, Also see, Sharma, M. (2014). Op. Cit., p. 59.

35. Ibid.

36. Ibid, pp. 7-8, Also see, Sharma, M. (2014). Op. Cit., pp. 59-60.

37. Ibid, p. 8, Also see, Sharma, M. (2014). Op. Cit., p. 60.

38. Ibid, pp. 8-9, Also see, Sharma, M. (2014). Op. Cit., p. 60.

39. Ibid, pp. 16-17, Also see, Sharma, M. (2014). Op. Cit., pp. 60-61.

40. S.N. Panda, S.K. Biswal, U.P. Tripathy. Deinking Technology; its Modification and Recent Developments: A Review. Asian J. Research Chem. 2018; 11(1):189-194.

Received on 24.10.2018 Modified on 31.10.2018

Res. J. Humanities and Social Sciences. 2019; 10(1):80-84.

DOI: 10.5958/2321-5828.2019.00014.7