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UNIDO has prepared and published over one hundred publications, papers, manuals and guidelines, primarily aimed at technical experts and policy makers in developing countries, though many are used by sector-related institutions and development organizations elsewhere.

The website www.leatherpanel.org is intended to provide an easy access to information sources on the leather, footwear and leather products industry, as well as to UNIDO publications related to the leather sector in one place, including earlier publications that were previously only available in hard copy.

Desalting of Raw Hides/Skins and Reuse of Dusted Salt in Pickling Operation

Due to climatic conditions the scope for green processing is limited in many countries, sodium chloride is widely used to preserve raw hides and skins. It contributes to a high volume of total dissolved solids (TDS) in the soak waste liquor. No commercially viable technology for treating effluent has been developed to date. A large amount of the salt sticking to the hide and skin surface can be removed by shaking the hides mechanically or manually.
Within the framework of the UNIDO regional programme for pollution control in the tanning industry in South-East Asia, a pilot demonstration unit was set up to demonstrate different options for

(a) desalting hides and skins prior to soaking and

(b) reusing dusted salt in the pickling operation after purifying the salt recovered.

This report covers the demonstrations carried out during the period January 1997 to February 2001 of desalting of salted raw stock and use of the recovered salt in pickling.

Download: 
PDF icon desalting_of_raw_hides_skins_salt_reuse.pdf
PDF icon Fact Sheet: desalting of raw hides and skins

Multiple Stage Evaporation System to Recover Salt from Tannery Effluent

UNIDO through its Regional Programme for Pollution Control in the Tanning Industry in South-East Asia has been actively looking for solutions to tackle saline tannery effluent. The following technologies have been tested at pilot scale demonstration units (PDUs):

  • Mechanical / manual removal of excess salt from wet salted hides and skins
  • Reverse osmosis (RO) of treated tannery effluent
  • Improved (accelerated) solar evaporation
  • Recycling of floats in the beamhouse
  • Use of ultrafiltration in tannery effluent.

This report provides preliminary estimates of costs of setting up a multistage evaporation system for recovery of salt from the concentrate (reject) resulting from the Reverse Osmosis (RO) of treated effluents..

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PDF icon multiple_stage_evaporation_for_salt_recovery_from_effluent_rv_2.pdf

Structure of Production Costs in Footwear Manufacture

The main objective of this survey presented during 14th UNIDO Leather Panel in Zlin/Czech Republic is two fold: to clarify actual differences in direct manufacturing costs of footwear production in selected countries and to review the proportion of different cost components/structures in the case of comparable labour intensive products such as footwear and/or its upper. As styles vary considerably (mainly due to fashion and market demands) and systems of costing used in different parts of the world are far from being uniform, a common scheme of costing had to be established. This was based on more or less standard types of shoe styles and on a suggested, simple cost computation algorithm.

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PDF icon Structure of Production Costs in Footwear Manufacture

Professional Training in the Leather Based Industries

Paper presented during the 12th UNIDO Leather and Leather Products panel 1995 provides an overview about the professional training. Conclusion is that, there is no reason for having different training programmes in industrialized and developing countries, so the creation of a uniform syllabus for the leather, footwear and other leather products is not only an opportunity but also a necessity - not to mention the financial rationale (economic scale of printing text books, producing illustration materials and training software).

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PDF icon professional_training_in_the_leatherbased_industries.pdf

What is the Future of Chrome Tanning?

What is future of the chrome tanning? What will be used as a tanning agent in horizont of 50 years? In this paper prepared in 1999 Mr. Frendrup analyzed possible trends and scenarios of leather manufacture. Many issues and predictions are still relevant, especially those concerning the recent EU regulations. For additional information see also IULTCS papers concerning chrome tanning http://www.iultcs.org/pdf/IUR-1_Chromiumandleatherresearch_Abalancedview...

 


 

Download: 
PDF icon Environmental Aspects of the Future of Tanning Methods
PDF icon What is the Future of (Chrome) Tanning?

Accelerated Evaporation of Saline Streams in Solar Pans

Total dissolved solids (TDS), specifically chlorides, in effluent are a major concern for its discharge into surface waters and its use for irrigation. Conventional treatment systems do not help reduce TDS in the industrial effluent. Taking advantage of the sunshine available for most part of the year, tanneries in Tamil Nadu, India, were required by the regulatory authority to segregate highly saline effluent (soak and pickle streams)  and evaporate it in solar pans. Due to very dissapointing results of evaporation in solar pans attempts have been made to accelerate the evaporation by simple means like combination of improved warming of the effluent and use of sprinklers. This paper reports on results of these pilot scale tests carried out under UNIDO Regional Programme in India during late 90's.

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PDF icon accelerated_evaporation_of_saline_streams_in_solar_pans.pdf

Benchmarking, Good Manufacturing Practice and Performance Assessment in the Footwear Industry

In market economies, specifically within (the present global) competitive market conditions actual performance of businesses is measured by the (international) market itself: efficient operations remain in business, produce profit and have potential to develop. In case of productive sectors of the economy, namely the agriculture, the industry, the trade and services such assessment having a post-facto character carries the risk of being late, i.e. it may jeopardize the business itself if it does not have sufficient resources to take corrective actions. Specifically assessment of industrial entities such as (sub)sectors, companies and production units plays an important role for governments and managements as its – timely obtained – results enable decision makers to initiate necessary actions.
The above considerations triggered the preparation of this study. In order to demonstrate practical applicability and usefulness of benchmarking, revealing good manufacturing practices and how thy can serve performance assessment in the industry, the paper is focusing – as an example – on footwear manufacturing and trade.

This paper was presented during the 15th UNIDO Leather Panel and later successfuly used in UNIDO TA to benchmark footwear sector and companies.

Download: 
PDF icon Benchmarking, Good Manufacturing Practice and Performance Assessment in the Footwear Industry

Professional Education and Training in the Leather-based Industries

Paper was prepared based on visits to some major footwear and leather training establishments in Europe and their training systems, methodology and syllabi . Information on professional education and training were collected from several other countries (e.g. Brasil, Hungary, South Africa). Experience gained through previous UNIDO assistance with regards human resource development was also considered. Outline proposals were prepared for discussion by the 13th UNIDO Leather Panel in Bologna in November 1997. A five stage structure was proposed which would allow trainees in any country to progress against known standards to the benefit of their company and themselves.

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PDF icon professional_training_in_the_leather_based_industries.pdf

Environmental Aspects of Footwear and Leather Products Manufacture

The survey is intended to cover the environmental impacts and health issues of the footwear and leather goods industries with particular reference to solid waste, air pollution and chemicals. The review covers quantification of solid wastes, technology available for reducing environmental impact and health risks and legislation. It was presented during th 13th UNIDO Leather Panel, Bologna November 1997.

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PDF icon Environmental Aspects of Footwear and Leather Products Manufacture

Some challenges in the treatment of tannery effluents

The only true leather-building substance in raw hide is corium collagen, everything else (hair, epidermis, fat, some proteinaceous matter etc.) has to be removed for which purpose substantial quantities of both general and specialty chemicals are needed; only some 20 % of them is actually retained by leather. Agglomerations of traditional tanning units with inadequate investment potential, lack of space and specific skills were conducive for setting up Common Effluent Treatment Plants (CETPs) servicing tannery clusters, the concept also adopted in relocations and/or establishing new leather clusters in developing countries. Due to only gradual increase in volumes of effluents and seasonal fluctuations associated with religious festivals, new CETPs are designed in modular way. On-site, physical-chemical (primary) treatment, including strict segregation of streams, catalytic oxidation of sulphide bearing spent floats, chrome management as well as equalization, settling, sludge removal and dewatering are by now already well-established technologies; the biological (secondary) treatment, typically using activated sludge method, often in raceways, in addition to high energy consumption, requires experienced personnel and close monitoring, in particular the removal of excess nitrogen (nitrification/denitrification). 

However, reutilisation and/or safe disposal of sludges remains a challenge to deal with. It appears that in very arid regions the best option to overcome the problem of Total Dissolve Solids (TDS, colloquially salinity) is to link tannery (C)ETPs with Municipal Wastewater Works (MWW).

Furthermore, it is important for the leather sector to take a proactive role in battling negative publicity and spreading of misleading information by fake green lobbies and pressure groups. Better coordination among various national, regional and global leather organizations, including R & D institutions would make a stronger impact.

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PDF icon challenges_in_the_treatment_of_tannery_effluents_p2.pdf

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