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Indian Leather Industry Overview
The leather industry occupies a place of prominence in the Indian economy in view of its massive potential for employment, growth and exports. There has been an increasing emphasis on its planned development, aimed at optimum utilisation of available raw materials for maximising the returns, particularly from exports. The exports of leather and leather products gained momentum during the past two decades. There has been a phenomenal growth in exports from Rs.320 million in the year 1965-66 to Rs.69558 million in 1996-97. Indian leather industry today has attained well merited recognition in international markets besides occupying a prominent place among the top seven foreign exchange earners of the country.
The leather industry has undergone a dramatic transformation from a mere exporter of raw materials in the sixties to that of value added finished products in the nineties. Policy initiatives taken by the Government of India since 1973 have been instrumental to such a transformation. In the wake of globalisation of Indian economy supported with liberalised economic and trade policies since 1991, the industry is poised for further growth to achieve greater share in the global trade.
Apart from a significant foreign exchange earner, leather industry has tremendous potential for employment generation. Direct and indirect employment of the industry is around 2 million. The skilled and semi-skilled workers constitute nearly 50% of the total work force.
The estimated employment in different sectors of leather industry is as follows:
Flaying, curing & Carcass Recovery:8,00,000 Tanning & Finishing:1,25,000 Full Shoe:1,75,000 Shoe Uppers:75,000 Chappals & Sandals:4,50,000 Leather Goods & Garments:1,50,000
Structure of the industry
The leather industry is spread in different segments, namely, tanning & finishing, footwear & footwear components, leather garments, leather goods including saddlery & harness, etc.
The estimated production capacity in different segments is as under
Hides:64 million pieces Skins:166 million pieces
Footwear & Footwear Components
Shoes:100 million pairs Leather shoe uppers:78 million pairs Non-leather shoes/chappals etc:125 million pairs Leather Garments:6 million pieces Leather Products:70 million pieces Industrial Gloves:40 million pairs Saddlery:6000 pieces
The major production centres for leather and leather products are located at Chennai, Ambur, Ranipet, Vaniyambadi, Trichi, Dindigul in Tamil Nadu, Calcutta in West Bengal, Kanpur in Uttar Pradesh, Jalandhar in Punjab, Bangalore in Karnataka, Delhi and Hyderabad in Andhra Pradesh.
Raw material supplies
There exists a large raw material base. This is on account of population of 194 million cattle, 70 million buffaloes, 95 million goats. According to the latest census, India ranks first among the major livestock holding countries in the world. In respect of sheep with 48 million sheeps, it claims the sixth position. These four species provide the basic raw material for the leather industry.
The annual availability of 166 million pieces of hides and skins is the main strength of the industry. This is expected to go up to 218 million pieces by the end of year 2000. Some of the goat/calf/sheep skins available in India are regarded as speciality products commanding a good market. Abundance of traditional skills in training, finishing and manufacturing downstream products and relatively low wage rates are the two other factors of comparative advantage for India.
Tanning and finishing capacity
With tanning and finishing capacity for processing 1192 million pieces of hides and skins per annum spread over different parts of the country, most of which is organised along modern lives, the capability of India to sustain a much larger industry with its raw material resource is evident. In order to augment the domestic raw material availability, the Government of India has allowed duty free import of hides and skins from anywhere in the world. It is an attraction for any foreign manufacturer who intends to shift his production base from a high cost location to low cost base.
Export Potential
The leather industry, one of the major foreign exchange earners of the country recorded significant growth since the beginning of the decade. Today the share of the value added finished products in the total exports from leather sector are 80% as against 20% in 1970s.
Top ten Indian leather exporters
Tata International Ltd. Florind Shoes Ltd. Punihani International Farida Shoes Ltd. Mirza Tanners Ltd. T. Abdul Wahid & Company Hindustan Lever Ltd. Super House Leather Ltd. RSL Industries Ltd. Presidency Kid Leather Ltd.
Indian Leather Footwear Industry
India is the world's second largest producer of footwear; its production estimated over 700 million pairs per annum. At about US $ 300 million per year, footwear accounts for 18
percent share of total exports of leather exports.
Various types of shoes produced and exported from India include dress shoes, casuals, moccasins, sports shoes, horacchis, sandals, ballerinas, and booties. Major production centres are Chennai (Madras), Delhi, Agra, Kanpur, Mumbai (Bombay), Calcutta and Jalandhar.
Most of the modern footwear manufacturers in India are already supplying to well established brands in Europe and USA. The large domestic market and the opportunity to cater to world markets makes India an attractive destination for technology and investments. Equally relevant is it for the footwear components industry, at this juncture, it is posed for real growth and diversification.
Indian Leather Goods Industry
Items produced by this sector include, in addition to bags, handbags, handgloves and industrial gloves, wallets, ruck sacks, folios, brief cases, travelware, belts, sports goods, upholstery and saddlery goods.
A surfeit of modern units in Chennai, Kanpur and Calcutta employing skilled human resources and equipped with modern and sophisticated machinery account for a diversified range of superlative small leather goods including bags, purses, wallets, industrial gloves etc. made of quality leathers of cows, sheep, goats and buffaloes. The products meet the requirement of bulk buyers and consumers in Europe, USA and Australia.
The major market for Indian leather goods is Germany, with an offtake of about 25 per cent of the leather goods produced in India followed by USA, UK, France and Italy. With products ranging from designer collections to personal leather accessories, this sector has a share of 20.53 per cent in the leather industry, while maintaining an average growth rate of 11 per cent recorded in the last five years.
Indian Saddlery Industry
India is one of the largest producers of saddlery and harness goods in the world. The saddlery industry was established in the 19th century primarily to cater to the needs of military and police. From then on initiatives were taken to develop, the industry and today there are over 150 units in the organised sector, out of which approximately 105 are 100% export oriented units.
Kanpur, in the state of Uttar Pradesh, is a major production centre for saddlery goods in India accounting for more than 95% of the total exports of saddlery items from India. Kanpur, because of its specialisation in tanning and finishing of buffalo hides is the only centre in the country where harness leather, which is major input for saddlery industry, is manufactured.
The export of saddlery and harn'ess items have showed an annual growth rate of about 40% reaching DM 64 million during 1998-99. The major importers of Indian saddlery are Germany, USA, UK, France, Scandinavia, Netherlands, Japan, Australia and New Zealand.
Indian Leather Garments Industry
The Leather Garment Industry occupies a place of prominence in the Indian leather sector. The product classification of leather garments comprise of jackets, long coats, waist coats, shirts, pant/short, children garments, motorbike jackets, aprons and industrial leather
garments.
Indian leather garments, which entered the world market only in the mid-eighties with exports of Rs. 15 crores in 1997-98, account for about Rs. 1530 crore in 1997-98. The major export destination of leather garments from India is Germany. In 1997, German imports of leather garments aggregated DM 1786 million of which DM 304 million worth of imports went from India. India, China and Turkey were the major suppliers of leather garments for the German market, as they accounted for about 78% of the market share.
Among the three major exporting nations of leather garments, India maintains a similar level of market share of about 20%, in both German and EU markets.
The main reasons reported for under utilisation of capacity are raw material shortage, high price of raw materials, lack of modernisation, financial constraints, power constraints and stringent environmental regulations.
Marketing of leather and leather products in Germany & the EU
The leather sector offers a good potential which Indian entrepreneurs can exploit in Germany and other EU markets characterised by ever growing competitiveness in terms of price and quality, on one hand, and the environmental considerations, on the other. With a strong foothold that the Indian leather industry has had for long in these markets, and its advantage of raw material and labour resources, Indian leather exporters can, and should, mount a concerted marketing campaign to wrest a share consistent with their inherent strength and potential.
This has to be done against the background of the well-known salient features of the German market:
The world's second largest import and export market A difficult buyers' market with hyper competition and high expectations A dynamic multi-faceted market with rapid technological development and
innovations A market where a considerable amount of buying power is devoted to satisfying individual needs
A market influenced by the rising average age of the population and low birth rate A market where environment awareness and eco-friendly production becomes more
and more a pre-requisite for successful marketing of products
Recipe for market intelligence
Market information through journals and magazines
Schuhmarkt Schuhkurier Lederwaren Report
Quick Market Assessment
Window shopping Backward calculation of price Catalogues/ leaflets
Trade Fairs
GDS – Dusseldorf » Herren Mode Woche - Munich Expo-Riva Schuh - Italy » Igedo Fashion Fair - Düsseldorf Leipzig Fashion Fair » SPOGA - Cologne Lederwarenmesse - Offenbach
SWOT Analysis of the Indian leather industry
Opportunities
Rising potential in the domestic market Growing fashion consciousness globally Use of information technology and decision support software to help eliminate the
length of the production cycle for different products Use of e-commerce in direct marketing
Strengths
High Growth Ready availability of highly skilled and cheap manpower Large raw material base Policy initiatives taken by the Government Capability to assimilate new technologies and handle large projects Continuous emphasis on product development and design upgradation
Weaknesses
Lack of warehousing support from the government International price fluctuation Huge labour force resulting in high labour charges Lack of strong presence in the global fashion market Unawareness of international standards by many players
Threats
Major part of the industry is unorganised Limited scope for mobilising funds through private placements and public issues
(many businesses are family-owned) Difficulty in obtaining bank loans resulting in high cost of private borrowing Stricter international standards High competition from East European countries and other Asian countries Lack of communication facilities and skills
Leather is a durable and flexible material created via the tanning of putrescible animal rawhideand skin,
primarily cattlehide. It can be produced through different manufacturing processes, ranging from cottage
industry to heavy industry.
Contents
[hide]
1 Forms of leather
o 1.1 Leather types
o 1.2 Leather from other animals
2 Leather production processes
3 Environmental impact
4 Role of enzymes in leather production
5 Preservation and conditioning of leather
o 5.1 Leather in book binding
6 Working with leather
7 Cordwain, "Cordovan" or "Spanish leather"
8 Leather in modern culture
9 Religious sensitivities to leather
10 Concern for animals and the environment and alternatives
11 See also
12 References
[edit]Forms of leather
Several tanning processes transform hides and skins into leather:
Vegetable-tanned leather is tanned using tannin and other ingredients found in vegetable matter,
such as tree bark prepared in bark mills, and other such sources. It is supple and brown in color, with
the exact shade depending on the mix of chemicals and the color of the skin. It is the only form of
leather suitable for use in leather carving or stamping. Vegetable-tanned leather is not stable in water;
it tends to discolor, and if left to soak and then dry it will shrink and become less supple and harder. In
hot water, it will shrink drastically and partly gelatinize, becoming rigid and eventually brittle. Boiled
leather is an example of this, where the leather has been hardened by being immersed in hot water,
or in boiled wax or similar substances. Historically, it was occasionally used as armor after hardening,
and it has also been used for book binding.
Chrome-tanned leather, invented in 1858, is tanned using chromium sulfate and other salts
of chromium. It is more supple and pliable than vegetable-tanned leather, and does not discolor or
lose shape as drastically in water as vegetable-tanned. It is also known as wet-blue for its color
derived from the chromium. More esoteric colors are possible using chrome tanning.
Aldehyde-tanned leather is tanned using glutaraldehyde or oxazolidine compounds. This is the
leather that most tanners refer to as wet-white leather due to its pale cream or white color. It is the
main type of "chrome-free" leather, often seen in automobiles and shoes for infants.
Formaldehyde tanning (being phased out due to its danger to workers and the sensitivity of
many people to formaldehyde) is another method of aldehyde tanning. Brain-tanned leathers fall
into this category and are exceptionally water absorbent.
Brain tanned leathers are made by a labor-intensive process which uses emulsified oils,
often those of animal brains. They are known for their exceptional softness and their ability to
be washed.
Chamois leather also falls into the category of aldehyde tanning and like brain tanning produces
a highly water absorbent leather. Chamois leather is made by using oils (traditionally cod oil) that
oxidize easily to produce the aldehydes that tan the leather to make the fabric the color it is.
Synthetic-tanned leather is tanned using aromatic polymers such as the Novolac or Neradol types
(syntans, contraction for synthetic tannins). This leather is white in color and was invented when
vegetable tannins were in short supply during the Second World War. Melamine and other amino-
functional resins fall into this category as well and they provide the filling that modern leathers often
require.Urea-formaldehyde resins were also used in this tanning method until dissatisfaction about
the formation of free formaldehyde was realized.
Alum-tawed leather is transformed using aluminium salts mixed with a variety of binders
and protein sources, such as flour and egg yolk. Purists argue that alum-tawed leather is technically
not tanned, as the resulting material will rot in water. Very light shades of leather are possible using
this process, but the resulting material is not as supple as vegetable-tanned leather.[1]
Rawhide is made by scraping the skin thin, soaking it in lime, and then stretching it while it dries. Like
alum-tawing, rawhide is not technically "leather", but is usually lumped in with the other forms.
Rawhide is stiffer and more brittle than other forms of leather, and is primarily found in uses such
as drum heads where it does not need to flex significantly; it is also cut up into cords for use in lacing
or stitching, or for making many varieties of dog chews.
Leather—usually vegetable-tanned—can be oiled to improve its water resistance. This supplements the
natural oils remaining in the leather itself, which can be washed out through repeated exposure to water.
Frequent oiling of leather, with mink oil, neatsfoot oil or a similar material, keeps it supple and improves its
lifespan dramatically.
Leather with the hair still attached is called hair-on.
[edit]Leather types
In general, leather is sold in four forms:
Full-grain leather refers to the leather which has not had the upper "top grain" and "split" layers
separated. The upper section of a hidethat previously contained the epidermis and hair, but were
removed from the hide/skin. Full-grain refers to hides that have not been sanded, buffed, or snuffed
(as opposed to top-grain or corrected leather) to remove imperfections (or natural marks) on the
surface of the hide. The grain remains allowing the fiber strength and durability. The grain also has
breathability, resulting in less moisture from prolonged contact. Rather than wearing out, it will
develop a patina over time. Leather furniture and footwear are made from full-grain leather. Full-grain
leathers are typically available in two finish types: aniline and semi-aniline.
Top-grain leather is the second-highest quality and has had the "split" layer separated away, making
it thinner and more pliable than full grain. Its surface has been sanded and a finish coat added to the
surface which results in a colder, plastic feel with less breathability, and will not develop a natural
patina. It is typically less expensive, and has greater resistance to stains than full-grain leather, so
long as the finish remains unbroken.
Corrected-grain leather is any leather that has had an artificial grain applied to its surface. The hides
used to create corrected leather do not meet the standards for use in creating vegetable-tanned or
aniline leather. The imperfections are corrected or sanded off and an artificial grain impressed into the
surface and dressed with stain or dyes. Most corrected-grain leather is used to make pigmented
leather as the solid pigment helps hide the corrections or imperfections. Corrected grain leathers can
mainly be bought as two finish types: semi-aniline and pigmented.
Split leather is leather created from the fibrous part of the hide left once the top-grain of
the rawhide has been separated from the hide. During the splitting operation, the top grain and drop
split are separated. The drop split can be further split (thickness allowing) into a middle split and a
flesh split. In very thick hides, the middle split can be separated into multiple layers until the thickness
prevents further splitting. Split leather then has an artificial layer applied to the surface of the split and
is embossed with a leather grain (bycast leather). Splits are also used to create suede. The strongest
suedes are usually made from grain splits (that have the grain completely removed) or from the flesh
split that has been shaved to the correct thickness. Suede is "fuzzy" on both sides. Manufacturers use
a variety of techniques to make suede from full-grain. A reversed suede is a grained leather that has
been designed into the leather article with the grain facing away from the visible surface. It is not
considered to be a true form of suede.[2]
Less-common leathers include:
Buckskin or brained leather is a tanning process that uses animal brains or other fatty materials to
alter the leather. The resulting supple, suede-like hide is usually smoked heavily to prevent it from
rotting.
Patent leather is leather that has been given a high-gloss finish. The original process was developed
in Newark, New Jersey, by inventorSeth Boyden in 1818. Patent leather usually has a plastic coating.
Shagreen is also known as stingray skin/leather. Applications used in furniture production date as
far back as the art deco period. The word "shagreen" originates from France.
Vachetta leather is used in the trimmings of luggage and handbags. The leather is left untreated and
is therefore susceptible to water and stains. Sunlight will cause the natural leather to darken in shade,
called a patina.
Slink is leather made from the skin of unborn calves. It is particularly soft, and is valued for use in
making gloves.
Deerskin is a tough leather, possibly due to the animal's adaptations to the its thorny and thicket-
filled habitats.[citation needed] Deerskin has been used by many societies including indigenous Americans.
Most modern deer skin is no longer procured from the wild, with deer farms breeding the animals
specifically for the purpose of their skins. Large quantities are still tanned from wild deer hides in
historic tanning towns such as Gloversville and Johnstown in upstate New York. Deerskin is used in
jackets and overcoats, martial arts equipment such as kendo and bogu, as well as personal
accessories like handbags and wallets.
Nubuck is top-grain cattle hide leather that has been sanded or buffed on the grain side, or outside,
to give a slight nap of short protein fibers, producing a velvet-like surface.
There are two other types of leather commonly used in specialty products, such as briefcases, wallets,
and luggage:
Belting leather is a full-grain leather that was originally used in driving pulley belts and other
machinery. It is found on the surface of briefcases, portfolios, and wallets, and can be identified by its
thick, firm feel and smooth finish. Belting leather is generally a heavy-weight of full-grain, vegetable-
tanned leather.
Nappa leather , or Napa leather, is chrome-tanned and is soft and supple. It is commonly found in
wallets, toiletry kits, and other personal leather goods.
The following are not "true" leathers, but contain leather material. Depending on jurisdiction, they may still
be labeled as "Genuine Leather":
Bonded leather , or "reconstituted Leather", is composed of 90% to 100% leather fibers (often scrap
from leather tanneries or leather workshops) bonded together with latex binders to create a look and
feel similar to that of leather at a fraction of the cost. This bonded leather is not as durable as other
leathers, and is recommended for use only if the product will be used infrequently. Bonded leather
upholstery is a vinyl upholstery that contains about 17% leather fiber in its backing material. The vinyl
is stamped to give it a leather-like texture. Bonded leather upholstery is durable and its manufacturing
process is more environmentally-friendly than leather production.
Bycast leather is a split leather with a layer of polyurethane applied to the surface and then
embossed. Bycast was originally made for the shoe industry and recently was adopted by the
furniture industry. The original formula created by Bayer was strong but expensive. Most of the bycast
used today is very strong and durable product. The result is a slightly stiffer product that is cheaper
than top grain leather but has a much more consistent texture and is easier to clean and maintain.
[edit]Leather from other animals
Tanned leather in Marrakech
Today, most leather is made of cattle skin, but many exceptions exist. Lamb and deer skin are used for
soft leather in more expensive apparels. Deer and elk skin are widely used in work gloves and indoor
shoes. Pigskin is used in apparel and on seats of saddles. Buffalo, goats, alligators, dogs, snakes,
ostriches, kangaroos, oxen, and yaks may also be used for leather.
Kangaroo skin is used to make items which need to be strong but flexible—it is the material most
commonly used in bullwhips. Kangaroo leather is favored by some motorcyclists for use inmotorcycle
leathers specifically because of its light weight and abrasion resistance.[3] Kangaroo leather is also used
for falconry jesses and soccer footwear.[4]
At different times in history, leather made from more exotic skins has been considered desirable. For this
reason certain species of snakes and crocodiles have been hunted to near extinction.[citation needed]
In the 1970s, farming ostriches for their feathers became popular, and ostrich leather became available
as a byproduct. There are different processes to produce different finishes for many applications, i.e.,
upholstery, footwear, automotive products, accessories and clothing.Ostrich leather is currently used by
many major fashion houses such as Hermès, Prada, Gucci, and Louis Vuitton. Ostrich leather has a
characteristic "goose bump" look because of the large follicles from which the feathers grew.
In Thailand, sting ray leather is used in wallets and belts. Sting ray leather is tough and durable. The
leather is often dyed black and covered with tiny round bumps in the natural pattern of the back ridge of
an animal. These bumps are then usually dyed white to highlight the decoration. Sting ray leather is also
used as grips on Japanese katana.
[edit]Leather production processes
Barrel for leather tanning, Igualada Leather Museum , Spain
Leather tanning in Fes, Morocco
Main article: Leather production processes
The leather manufacturing process is divided into three fundamental sub-processes: preparatory
stages, tanning and crusting. All true leathers will undergo these sub-processes. A further sub-process,
surface coating, can be added into the leather process sequence but not all leathers receive surface
treatment. Since many types of leather exist, it is difficult to create a list of operations that all leathers
must undergo.
The preparatory stages are when the hide/skin is prepared for tanning. Preparatory stages may include:
preservation, soaking, liming, unhairing, fleshing, splitting, reliming, deliming, bating,degreasing,
frizing, bleaching, pickling and depickling.
Tanning is the process which converts the protein of the raw hide or skin into a stable material which will
not putrefy and is suitable for a wide variety of end applications. The principal difference between raw
hides and tanned hides is that raw hides dry out to form a hard inflexible material that when re-wetted (or
wetted back) putrefy, while tanned material dries out to a flexible form that does not become putrid when
wetted back. Many different tanning methods and materials can be used; the choice is ultimately
dependent on the end application of the leather. The most commonly used tanning material is chromium,
which leaves the leather, once tanned, a pale blue color (due to the chromium); this product is commonly
called "wet blue". The hides once they have finished pickling will typically be between pH 2.8 and 3.2.[citation
needed] At this point, the hides would be loaded in a drum and immersed in a float containing the tanning
liquor. The hides are allowed to soak (while the drum slowly rotates about its axle) and the tanning liquor
slowly penetrates through the full substance of the hide. Regular checks will be made to see the
penetration by cutting the cross-section of a hide and observing the degree of penetration. Once a good,
even degree of penetration exists, the pH of the float is slowly raised in a process called basification. This
basification process fixes the tanning material to the leather and the more tanning material fixed, the
higher the hydrothermal stability and increased shrinkage temperature resistance of the leather. The pH
of the leather when chrome tanned would typically finish somewhere between 3.8 and 4.2.[citation needed]
Crusting is when the hide/skin is thinned, retanned and lubricated. Often, a coloring operation is included
in the crusting subprocess. The chemicals added during crusting have to be fixed in place. The
culmination of the crusting subprocess is the drying and softening operations. Crusting may include the
following operations: wetting back, sammying, splitting, shaving, rechroming, neutralization,
retanning, dyeing, fatliquoring, filling, stuffing, stripping, whitening, fixating, setting, drying, conditioning,
milling, staking, and buffing.
For some leathers, a surface coating is applied. Tanners refer to this as finishing. Finishing operations
may include: oiling, brushing, padding, impregnation, buffing, spraying, roller coating, curtain
coating, polishing, plating, embossing, ironing, ironing/combing (for hair-on), glazing andtumbling.
[edit]Environmental impact
Leather is a product with high environmental impact, most notably due to:
the impact of livestock
the heavy use of polluting chemicals in the tanning process
air pollution due to the transformation process (hydrogen sulfide during dehairing
and ammonia during deliming, solvent vapors).
One tonne of hide or skin generally leads to the production of 20 to 80 m3 of turbid and foul-smelling
wastewater including chromium levels of 100–400 mg/L, sulfide levels of 200–800 mg/L and high levels of
fat and other solid wastes, as well as notable pathogen contamination. Pesticides are also often added for
hide conservation during transport. With solid wastes representing up to 70% of the wet weight of the
original hides, the tanning process comes at a considerable strain on water treatment installations.[5]
Tanning is especially polluting in countries where environmental norms are lax, such as in India, the
world's third-largest producer and exporter of leather. To give an example of an efficient pollution
prevention system, chromium loads per produced tonne are generally abated from 8 kg to
1.5 kg. VOC emissions are typically reduced from 30 kg/t to 2 kg/t in a properly managed facility. A review
of the total pollution load decrease achievable according to the United Nations Industrial Development
Organization [6] posts precise data on the abatement achievable through industrially proven low-waste
advanced methods, while noting that "even though the chrome pollution load can be decreased by 94%
on introducing advanced technologies, the minimum residual load 0.15 kg/t raw hide can still cause
difficulties when using landfills and composting sludge from wastewater treatment on account of the
regulations currently in force in some countries."
In Kanpur, the self-proclaimed "Leather City of World" and a city of 3 million people on the banks of the
river Ganges, pollution levels were so high that despite an industry crisis, the pollution control board has
decided to seal 49 high-polluting tanneries out of 404 in July 2009.[7] In 2003 for instance, the main
tanneries effluent disposal unit was dumping 22 tonnes of chromium-laden solid waste per day in the
open.[8]Scientists at the Central Leather Research Institute in India have developed biological methods for
pretanning as well as better chromium management.
The higher cost associated to the treatment of effluents that to untreated effluent discharging leads to
illegal dumping to save on costs. For instance, in Croatia in 2001, proper pollution abatment cost 70-100
USD/t of raw hides processed against 43 USD/t for irresponsible behaviour.[9]
No general study seems to exist but the current news is rife with documented examples. In November
2009 for instance, it was discovered that one of Uganda's main leather producing companies directly
dumped its waste water in a wetland adjacent to Lake Victoria.[10]
[edit]Role of enzymes in leather production
Enzymes like proteases, lipases and amylases have an important role in the soaking, dehairing,
degreasing, and bating operations of leather manufacturing.
Proteases are the most commonly used enzymes in leather production. The enzyme used should not
damage or dissolve collagen or keratin, but should be able to
hydrolyze casein, elastin, albumin and globulin-like proteins, as well as non-structured proteins which are
not essential for leather making. This process is called bating.[11]
Lipases are used in the degreasing operation to hydrolyze fat particles embedded in the skin.[12]
Amylases are used to soften skin, to bring out the grain, and to impart strength and flexibility to the skin.
These enzymes are rarely used.
[edit]Preservation and conditioning of leather
The natural fibers of leather will break down with the passage of time. Acidic leathers are particularly
vulnerable to red rot, which causes powdering of the surface and a change in consistency. Damage from
red rot is aggravated by high temperatures and relative humidities, and is irreversible.
Exposure to long periods of low relative humidities (below 40%) can cause leather to become desiccated,
irreversibly changing the fibrous structure of the leather.
Various treatments are available such as conditioners, but these are not recommended
by conservators since they impregnate the structure of the leather artifact with active chemicals, are
sticky, and attract stains.
[edit]Leather in book binding
Leather used in book binding has many of the same preservation needs: protection from high
temperatures, high relative humidity, low relative humidity, fluctuations in relative humidity, light exposure,
dust buildup, pollution, mold, and bug infestation.[13][14]
For books with red rot, acid-free phase boxes and/or polyester dust jackets (Dupont Mylar Type D or ICI
Mellinex 516) are recommended to protect the leather from further handling damage and as well as to
prevent the residues from getting on hands, clothes, the text block, and nearby books.[15]
The debate on the use of dressings for preservation of book bindings has spanned several decades as
research and experimental evidence have slowly accumulated. The main argument is that, done
incorrectly, there are multiple disadvantages and that, done correctly, there is little to no preservation
advantage. Pamphlets and guidelines give numerous downsides to dressings use, including: the dressing
becoming increasingly acidic, discolor and stain the leather, oxidize (penetration and expansion of oils
including displacement and weakening of fibers) and stiffen, leave a sticky surface, collect dust, wick into
adjacent materials, form unstable surface spews, encourage biological deterioration and mold growth,
block surface porosity, impede further treatment, wet and swell the leather, affect surface finishes, and
desiccate or dry out the leather.[16] Meanwhile, scientific experiments have shown no substantial benefits.
[17] The main authorities on the subject therefore discourage it, with a caveat for special cases done under
the direction of a conservator.[13][15][16]
[edit]Working with leather
Main article: Leather crafting
Leather can be decorated by a variety of methods, including pyrography and beading.
[edit]Cordwain, "Cordovan" or "Spanish leather"
Fragment of Cordwain
Cordwain, once a synonym of cordovan (through Old French cordewan) meaning "from Córdoba"
describes painted or gilded embossed leather hangings manufactured in panels and assembled for
covering walls as an alternative to tapestry. Such "Cordovan leathers" were a north African style that was
introduced to Spain in the ninth century (hence it is sometimes referred to as 'Spanish leather'); in Spain
such embossed leather hangings were known as guadamecí or guadamecil, from the Libyantown
of Ghadames, while cordobanes signified soft goat leather.[18] Leather was even more proof against
draughts and dampness than tapestry, and it was unaffected by insects. From the fourteenth century, the
technique in which panels of wet leather were shaped over wooden moulds, painted, then oil-gilded and
lacquered, reached Flanders and Brabant in the Low Countries. Though there werecraftsmen in several
cities (such as Antwerp, Brussels, Ghent), the major handicraft center for thiscordwain was Mechelen,
where it was mentioned as early as 1504.
Embossed gilded leather hangings in a Dutch interior, ca 1730, painted by Philip van Dijk (Mauritshuis)
Patterns for these panels followed fashions in silk damask, at some lag in time, since the high-relief
wooden moulds were laborious to make. After the second half of the 18th century, this
luxurious artisan product was no longer made,[19] its place taken in part by chintz hangings and
printed wallpapers. Cordwainer is still used to describe someone in the profession of shoemaking.
[edit]Leather in modern culture
Due to its excellent resistance to abrasion and wind, leather found a use in rugged occupations. The
enduring image of a cowboy in leather chaps gave way to the leather-jacketed and leather-
helmeted aviator. When motorcycles were invented, some riders took to wearing heavy leather jackets to
protect from road rash and wind blast; some also wear chaps or full leather pants to protect the lower
body. In fact, top-quality motorcycle leather is superior for abrasion protection to any practical man-made
fabric, and is still used in racing. Many sports still use leather to help in playing the game or protecting
players; its flexibility allows it to be formed and flexed.
The term leathering is sometimes used in the sense of a physical punishment (such as a
severe spanking) applied with a leather whip, martinet, etc.
Leather fetishism is the name popularly used to describe a fetishistic attraction to people wearing leather,
or in certain cases, to the garments themselves.
Many rock groups (particularly heavy metal and punk groups in the 1980s) are well-known for wearing
leather clothing. Leather clothing, particularly jackets, are common in the heavy metal and Punk
subculture. Extreme metal bands (especially black metal bands) and Goth rock groups have extensive
leather clothing, i.e. leather pants, accessories, etc.
Many cars and trucks come with optional or standard "leather" seating. This can range from
cheap vinyl imitation leather, found on some low cost vehicles, to real Nappa leather , found on luxury car
brands like Mercedes-Benz, BMW, and Audi.
Leather biodegrades slowly, and takes 25–40 years to decompose.
[edit]Religious sensitivities to leather
In religiously diverse countries, leather vendors are typically careful to clarify the kinds of leather used in
their products. For example, leather shoes will bear a label identifying the animal from which the leather
was taken. In this way, a Muslim would not accidentally purchase pigskinleather,[citation needed] and
a Hindu could avoid cow leather. Many Hindus who are vegetarians will not use any kind of leather.
Such taboos increase the demand for religiously neutral leathers like ostrich and deer.
Judaism forbids the comfort of wearing shoes made with leather on Yom Kippur, Tisha B'Av , and during
mourning.[20]
Jainism prohibits the use of leather since it is obtained by killing animals.
[edit]Concern for animals and the environment and alternatives
Vegans and animal rights activists boycott the use of all items made from leather, believing the practice of
wearing animal hides is unnecessary and cruel in today's society. Animal rights groups such
as PETA have called for boycotts and encourage the use of alternative materials such as synthetic
leathers.
Many pseudo-leather materials have been developed, allowing those who wish to wear leather-like
garments to do so without actually wearing leather. One example of this is vegan microfiber, which claims
to be stronger than leather when manufactured with strength in mind. Vinyl
materials, pleather, Naugahyde, Durabuck, NuSuede, Hydrolite, and other alternatives exist, providing
some features similar to leather.[citation needed]
[edit]See also
Types of leather
Aniline leather , a leather treated with aniline as a dye
Artificial leather , a fabric of finish intended to substitute for leather
Bicast leather , a synthetic upholstery product
Boiled leather , a historical construction material
Bonded Leather , man-made material composed of leather fibers
Chamois leather , leather made from the skin of the mountain antelope or Chamois
Composition leather , man-made leather made from recycled leather offcuts, trimmings or shavings
Corinthian leather , a marketing term used by Chrysler in the 1970s
Crocodile leather , leather from a crocodile
Morocco leather , a type of goatskin dyed red
Nappa leather , a full-grain leather
Ostrich leather , leather from an ostrich
Patent leather , leather with a high gloss and shiny finish
Pleather , a term for artificial leather
Poromeric imitation leather , a group of synthetic leather substitutes
Vegan leather , an artificial alternative to traditional leather
Leather fabrication
British Museum leather dressing , a conservator's treatment for display items
Leather carving , a process of cutting and stamping to give a three-dimensional appearance
Leather crafting , the practice of making leather into crafts or pieces of art
Liming (leather processing) , a process of treating leather
Tanning
Other
Adarga , a hard leather shield
Henry Burk – inventor of the alum and sumac tanning process
Horse tack , various equipment and accessories worn by horses, much of which is made of leather
Leather skirt
Leather subculture
Mink oil , leather treatment
Neatsfoot oil , leather treatment
Saddle soap , leather cleaning and conditioning
Leather Jacket
Leather, a material made from tanned animal hides, has been used as
clothing since the earliest days of human existence. Prehistoric people
wrapped animal skins around their bodies for warmth and to absorb the
magical powers that they believed the skins imparted to them. Phoenician
sailors often brought brightly embroidered leather garments from Babylonia
to the countries they visited. Leather shoes were found in the tombs of
Egyptian pharaohs.
Soldiers of the Roman Empire invaded the lands of northern Europe and
discovered Teutonic nomads wearing leather garments as protection
against the harsh elements. When these soldiers returned to Rome with
leather pants, the toga-garbed officials of the city tried to ban their use, but
to no avail. Romans were soon using leather for shoes and tunics as well as
for breastplates and shields. In fact, the first recorded tanning guild was
formed in the Roman Empire.
In the Middle Ages, the Moors introduced the European world to softer
Cordovan leather which they made from goatskin. By the Renaissance,
tanners' guilds had been organized all over Europe. The Mayan, Incan, and
Aztec cultures in Central and South America also used leather, as did the
American Indians, who sewed garments from buckskin, doeskin, and buffalo
hide.
During the Stone Age, garments were held together with leather straps that
had been threaded through holes punched in the hide with crude
implements made of stone. The hides were stiff and did not last long before
putrefaction made them unwearable. Later, people learned to soften the
hides by rubbing them with animal fat and used stones to clean the animal
cells from the skins. It is also possible that in trying to dye the skins with
various substances, early people discovered further preservation methods.
Preservation methods have varied over the centuries. Hides have been
smoked, salted, soaked in urine, rubbed with animal dung, beaten, and
dragged over sharp sticks. Prehistoric people and some modern Eskimos
have even resorted to chewing the skins to remove hair, pieces of flesh, and
ultimately, to soften the leather. In some cultures, the skins were sprinkled
with talc and flour to replace the natural oils. Women's leather garments
were often doused with perfumes.
Although leather was a valuable trade commodity, the tanning work was
dirty and odorous, and leather workers were usually relegated to the
outskirts of town.
Ancient Hebrews are credited with inventing the first tanning process using
oak bark. The American Indians used fish oil for the same purpose.
American colonists found that plants such as the hemlock and chest-nut
trees could also be used for tanning. In the 19th century, machines were
developed to perform these processes and an American chemist developed a
tanning method using chromium salts that cut the processing time from
weeks or months to just a few hours.
Raw Materials
Antelope, buckskin, lambskin, sheepskin, and cowhide are the hides most
commonly
used to make leather jackets. As soon as the skin is removed from the
animal at the meat processing plant, it is refrigerated, salted, or packed in
barrels of brine. It is then sent to the tannery where the skins undergo a
series of processes designed to preserve and soften the hides. The work
performed at the tannery is of utmost importance to insure that the
resulting garment is of high quality.
Sewing materials such as thread, lining, seam tape, buttons , snaps, and
zippers are generally purchased from outside vendors and stored in the
garment factory.
The Preparation Process
Trimming and cleaning
1 The skins are trimmed and sorted according to size, weight, and
thickness. It is necessary to remove any remaining proteins that could
stimulate the growth of bacteria. To this end, the skins are soaked in
revolving drums filled with water, bactericides, and detergents. Hair
is removed with the application of chemical sprays or lime solutions. A
scudding machine fitted with dull blades scrapes off any excess hair.
Another round of washing (de-liming) removes these chemicals before
the hides are soaked in an acid solution and then bated, an enzyme
treatment to further remove the skins' collagens. Finally, the hides
are pickled with salt and sulfuric acid.
Tanning
2 The hides undergo one of three types of tanning. Vegetable tanning
requires the most time with the skins soaked in progressively stronger
tannic acid solutions for several weeks. However, some soft leathers,
such as lambskin, may be soaked for as little as 12 hours.
Mineral tanning is significantly faster but can change the color of the
leather. For this method, the skins are placed in alum salt-filled drums
fitted with paddles that provide a constant agitating motion.
The third method, oil tanning, is the one that resembles the ancient
methods most closely. Here, fish oil is sprayed onto the skins.
Washing and drying
3 After the skins have been tanned, they are washed once again and
wrung out thoroughly. Then the skins are passed under a band knife,
which cuts the skins to a uniform thickness, and placed on conveyer
belts which carry them to drying tunnels. Usually, the skins are
stretched on frames to prevent shrinkage during the drying stage. To
combat the stiffness that drying produces, the hides are sprayed with
water and soap and allowed to hang for a period of time.
After the skins have been conditioned, they are placed in machines
designed to rhythmically manipulate the leather so that the fibers are
further loosened and made more flexible. In the final drying period,
the hides are hung in vacuum-drying cabinets.
When the skins are thoroughly dried, they are buffed with revolving
steel cylinders covered with abrasive paper. Suede finishes are
produced by passing the hides under high-speed emery wheels. At this
point, glazes, dyes, and lacquers are applied. The skins are now ready
to be sent to the garment factory.
The Manufacturing Process
The development of high-speed sewing machinery changed the face of
traditional sewing factories where one person may have worked on a single
garment from start to finish. Because leather garments are considered
luxury items, hand-construction by highly skilled artisans is still sought by
many consumers. However, the following steps are those used in factory
mass production.
Jacket design
1 Garment manufacturers typically employ designers to create
patterns from which the clothing is made. Computerized machines
grade the designs according to government anthropometric tables
which assign sizes based on body height and weight. The computer
then produces patterns in a range of sizes from the original design.
Cutting
2 The tanned leather is placed on moving tables called spreaders.
Although modern technology allows several layers of fabric to be cut
simultaneously, leather is usually cut one layer at a time. The pattern
is placed on top of the leather. This is accomplished in one of two
ways; tissue-paper patterns may be pinned onto the leather, or the
pattern may be marked with tailor's chalk. The spreading table works
on the conveyer system, moving the fabric to the cutting machine,
which is fitted with either rotary blades or band-knives. The table is
either guided by a human operator or run automatically. The most
recent technological advance is the computerized laser beam system
in which the fabric seams are vaporized rather than cut.
Lining material for the jacket is cut in the same manner. Because it is
of a much thinner weight, lining can be placed on the spreaders in
multiple layers.
Jacket assembly
3 The jacket is assembled in roughly this order: the sides are stitched
to the back portion, sleeve underseams are stitched together, and the
sleeves are attached to the armholes. The attachment of finishing
pieces such as collars, cuffs, buttonholes, buttons, zippers, and
pockets varies according to the design of the jacket. Patch pockets are
sewn onto the side pieces before they are stitched to the back portion,
and side pockets are sewn in at the same time that the sides are
attached to the back. Generally, lining material is attached to each
piece before it is sewn onto the jacket.
In mass production, the pieces are moved along a highly sophisticated
production line using integrated automatic sewing machines that are
capable of sewing as many as 8,000 stitches per minute. In a
sequential system, one sewing machine stitches a particular section of
the jacket and then moves the garment to another sewing machine
which performs the next step. For example, after one machine stitches
a cuff to the sleeve, the sleeve moves to another machine where it is
attached to the jacket armhole.
A tandem sewing system calls for two or more machines to work on
the same garment simultaneously. In this instance, one machine
attaches buttons to the front of the jacket while another machine
applies the collar.
Each step, from setting thread and needle positions to aligning the
fabric to extracting the sewed materials, is pre-programmed. Each
sewing machine is equipped with under-bed trimming devices that
automatically knot and cut threads after each seam is sewn. Excess
threads are carried away to waste receptacles by streams of
compressed air.
Operators regulate the work at each station with a modified presser-
foot or from a control panel. A stop-motion device allows the operator
to halt production to make adjustments such as replacing broken
threads or needles.
Molding and pressing
4 A number of pressing processes incorporating heat application,
steaming, and blocking are employed to complete the transformation
of the animal skins into a jacket. Buck presses equipped with controls
and gauges to regulate the amount of steam and pressure are used to
give the jacket its distinctive shape, whether a bomber- or blazer-
styled jacket. Curved blocks are placed around the collars and cuffs
and then heat is applied. The blocks are removed, leaving the collars
and cuffs curved.
Final inspection
5 Each jacket is inspected by hand before it leaves the factory floor.
The completed jackets are then sheathed in plastic bags, packed into
cartons, and shipped to the retailer.
Quality Control
The thoroughness of the tanning process is designed to produce skins that
are supple and free of bacteria-causing proteins. Garment manufacturers
inspect each shipment of skins for marks, tears, stains, and imperfections.
Today's automated sewing systems are self-correcting. Sophisticated
lubricating systems composed of pumps, reservoirs, fluidic controls, and
electronic controls insure that the garments are manufactured at a
consistent level of quality.
The Future
Although the leather goods industry suffered slightly during the most recent
recession, and merchandisers were compelled to implement discount
strategies, the Leather Apparel Association predicts a strong comeback
during the last decade of the 20th century as many companies expand their
clothing lines. New technologies such as the laser cutter are also increasing
the rate of production.
As with the fur industry, the leather industry has been the target of some
animal rights groups who denounce the killing of animals for human benefit,
particularly to create "luxury" items. In an effort to address these concerns,
some clothing manufacturers have increased production of artificial leather,
a material made from synthetic fibers, which does not use any animals and
is less expensive. However, jackets and coats made from real leather remain
fashionably popular.
Read more: How leather jacket is made - material, history, used, processing, steps, industry, machine, History, Raw Materials, The Preparation Process, The Manufacturing Process of leather jacket http://www.madehow.com/Volume-2/Leather-Jacket.html#ixzz1DNLlTXEe
Chemicals Used in Leather ProcessingUseful Information
The following is a list of chemicals commonly used in leather making:
Beamhouse and Tanyard
Biocides
Biocides prevent the growth of bacteria which can damage the hides or skins during the soaking process
Surfactants
Surfactants are used to help with the wetting back of the hides or skins
Degreasers
Degreasers help with the removal of natural fats and greases from the hides or skins
Swell regulating agents
Swell regulating agents help prevent uneven swelling of the hides or skins during liming
Lime
Lime is used to swell the hides or skins
Sodium sulphide
Sodium sulphide chemically destroys the hair on hides or skins
Sodium hydrosulphide
Sodium hydrosulphide chemically destroys the hair on hides or skins. It does not create as much swelling as sodium sulphide
Low sulphide unhairing agents
Low sulphide unhairing agents help to reduce the amount of sulphides used in a tannery thus reducing the environmental impact of tanneries
Caustic soda
Caustic soda is used during the liming process to help swell the hides or skins
Soda ash
Soda ash is used during the soaking or liming processes to help raise the pH of the hides or skins
Ammonium sulphate
Ammonium sulphate is used during the deliming process and helps remove lime from the hides or skins
Ammonium chloride
Ammonium chloride is used during the deliming process and helps remove lime from the hides or skins
Sodium metabisulphite
Sodium metabisulphite is used during the deliming process and helps prevent the formation of toxic hydrogen sulphide gas during deliming. It also acts as a bleaching agent
Formic acid
Formic acid is used during the pickling process to lower the pH of the hides or skins
Sulphuric acid
Sulphuric acid is used during the pickling process to lower the pH of the hides or skins
Salt
Salt is used during the pickling process to prevent acid swelling of the hides or skins
Sodium formate
Sodium formate is used during the tanning process to assist with the penetration of chromium tanning salts into the hides or skins
Chromium sulphate
Chromium sulphate is the tanning agent used to make wet blue
Aldehyde tanning agents
Aldehydes are tanning agents used to make wet white
Magnesium oxide
Magnesium oxide is used during basification and raises the pH of the hide or skin to allow the chromium or aldehyde to chemically bind to the skin protein
Fungicide
Fungicides are chemicals that are used to prevent the growth of moulds or fungi on tanned hides or skins
Dyehouse
Surfactants / Wetting agents
Surfactants help in the wetting back of the wet blue in the dyehouse
Degreasers
Degreasers help remove grease or fats that may be present on the wet blue as a result of the wet blue coming into contact with machinery
Sodium formate
Sodium formate helps raise the pH during the neutralization process
Sodium bicarbonate
Sodium bicarbonate helps raise the pH during the neutralization process
Formic acid
Formic acid reduces the pH for the rechroming process or helps with chemically fixing dyehouse chemicals to the leather at the end of the dyehouse processes
Chrome syntans
Chrome syntans are used during rechroming to improve the softness of the final leathet
Chromium sulphate
Chrmium sulphate is used during rechroming to improve the softness of the final leather
Syntans
Syntans are used to give properties such as softness, fullness, roundness to the leather
Resins
Resins are used to give fullness and a tight grain to the leather
Polymers
Polymers are used to give fullness and a tight grain to the leather
Dyes
Dyes are used to give the leather a colour desired by the customer
Dyeing auxiliaries
Dyeing auxiliaries help disperse the dyes evenly
Fatliquors
Fatliquors are oils that are added to leather to give softness to the final leather
Finishing
Acrylic resins
Acrylic resins give specific properties to the leather finish such as adhesion, water resistance
Butadiene resins
Butadiene resins give specific properties to the leather finish such as good coverage
Polyurethane resins
Polyurethane resins give specific properties to the leather finish such as good toughness and good lightfastness
Fillers
Fillers help fill small blemishes on the leather surface
Dullers
Dullers help reduce the gloss of the finish
Crosslinkers
Crosslinkers are used to toughen the leather finish and improve the water resistance properties of polyurethanes
Handle modifiers
Handle modifiers are used to give the leather surface a waxy or slippery feel
Nitrocellulose lacquers
Nitrocellulose lacquers are used in the top coat of a leather finish
Acrylic lacquers
Acrylic lacquers are used in the top coat of a leather finish
Polyurethane lacquers
Polyurethane lacquers are used in the top coat of a leather finish
Viscosity modifiers
Viscosity modifiers are used to increase the viscosity of a finish mixture
Pigments
Pigments are colouring agents that help hide defects on the leather surface
Dyes
Dyes are colouring agents that are used to slightly change the colour of the leather finish or to give the leather finish a more natural look
Defoamers
Defoamers are used to prevent bubbles from forming in the finish mixture