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Leather processing

In an age of plastics, metals and synthetics, leather has kept its place as a product of superior quality. As a result, tanning remains an essential economic activity. Leather processing can be done at the small-scale or large-scale level, all to varying degrees of sophistication.

The tanning industry has been subject to important challenges and changes. Foremost has been the introduction of processing technologies with less impact on the environment. As the production of finished leather is concentrated in developing countries, UNIDO, together with other partners, have provided support to enhance tanning industry practices in developing countries.

Cleaner leather production technologies remain UNIDO’s main focus in the field of leather processing. Cleaner production applications include green hide and skin processing (supply of raw material from slaughterhouses without preservation, e.g. salting), water management (use minimum volume of process water), recycling (e.g. in liming) and chromium recovery (after tanning), hair saving (to reduce dissolved solids in effluent) and application of environmentally friendly chemicals (e.g. enzymes). Special attention is also given to occupational health and safety (OHS) in tanneries.

Leather industry expert Richard Daniels In association with IULTCS, SLTC and the United Nations Industrial Development Organisation (Unido), has released an extensive guide to leather manufacturing.

The 10-part guide, which contains insight on leathermaking, was created to give aspiring leather technicians a self-training resource for the procedures used in making a wide variety of leathers. It includes 300 technical diagrams.

The study is optimised for mobile or tablet viewing and covers the raw material properties, manufacturing procedures and outcomes, and production of major leather types including:

Bovine hides
Hair sheep and goatskins
Wool-bearing sheepskins.

You can find the full guide in 10 parts (plus summary) below. The full guide was presented during the XXXVI IULTCS Congress in Ethiopia in November 2021.

Hides, skins and leather form a critical strategic sector for the economic and industrial development of Ethiopia. 

Realizing the diverse and unique issues of women employees, the EU funded  LISEC project integrated gender mainstreaming as a cross-cutting theme. The gender mainstreaming process aims to promote gender equality and women’s empowerment in selected tanneries, slaughterhouses, and hide and skin trading companies.

In order to have a deeper understanding of the gender issues that exist within the leather industry and thereby devise a strategy to address the identified concerns, UNIDO, through its LISEC project, collaborated with the gender directorates of MoTI and LIDI to conduct this gender analysis. The main
objective of the gender analysis was to gain a clear insight into the gender issues affecting the leather value chain and thus identify recommended strategic actions for more gender-responsive planning and implementation from 6 abattoirs, 6 tanneries and 2 hide and skin trading companies.

The General Objective of the study was to conduct a gender analysis to have a deeper understanding of gender issues in the leather value chain and thereby devise a strategy to address the identified issues.
Specifically, the gender analysis aimed to:
 Assess the representation, participation, and decision-making of women and men employees.
 Assess women and men stakeholders’ access to and control over resources.
 Understand cultural gender roles, norms, relations, stereotypes, prejudices affecting women and men.
 Identify the presence and justification for sex/gender-based job segregation.
 Assess practices of recruitment, retention, promotion of women and men employees.
 Assess implementation of gender-related provisions (including the revised labour law) within stakeholder companies.
 Examine the presence of conducive and family/women-friendly work environments.
 Assess migration patterns to address women’s integration in the project in the best way possible.
 Provide strategic recommendations to address challenges that women and men face, while promoting gender equality as well as women’s empowerment.

The course Introduction to Leather Testing is designed for training institutions, private companies and individuals that require understanding of both the theory and application of a wide array of standard test methods in utilize in the leather industry. The course is recommended to be used in a blend of classroom instruction using training content or self-learning along with allocation of time for hands on application in the laboratory. All courses provide opportunity for continuous professional development and lifelong learning.

The Course is divided into five modules:

M1: Fundamentals in Material Testing

M2: Basics in Leather Testing

M3: Physical Testing

M4: Fastness Testing

M5: Chemical Testing

 

Content was developed and prepared as a joint effort between UNIDO, FILK Freiberg Institute and Common Sense. Dr. S. Dietrich will guide you through the course. The course is offered free of charge and a certificate issued upon successful completion of the course.

The course will be available also in additional languages. The course was developed thanks to a generous support from the Government of Japan.

To register to the course, please use this link:  https://learning.unido.org/course/view.php?id=56

"SAFE Leather" must mean safe for operators and workers, as well as safe for consumers and communities. Company management must ensure that the workplace provides workers and anyone else attending the workplace with access to appropriate first aid equipment. Management must also ensure that the workers have access to an adequate number of persons who have been trained to administer first aid.

First Aid course/training should be mandatory for all emplyees. 

First Aid course Modules
Module 1: First Aid Kit - content
Module 2: First Aid Dealing with Heart Attack
Module 3: First Aid Dealing with Burns
Module 4: First Aid Dealing with Accidents Involving Chemicals
Module 5: First Aid Dealing with Contusions
Module 6: First Aid Dealing with Eye Injuries
Module 7: First Aid Dealing with Severe Bleeding
Module 8: First Aid Dealing with Eelectricity

 

To enroll into the course please follow the linkhttps://learning.unido.org/course/view.php?id=19

UNIDO Course Introduction to treatment of tannery effluents

The course, “Introduction to Treatment of Tannery Effluent” is designed for training institutions, private companies, and individuals that require an understanding of effluent treatment methods in the leather industry. The course is recommended to be used in a blended approach via classroom instruction using training content or self-learning along with an allocation of time for hands-on application in the laboratory.   There are 5 modules in this course as below:

Module 1: Load, norms, in-house treatment. This module will explain the aim of effluent treatment; pollution load and the main wastewater quality parameters; typical discharge norms.  It will also offer a general overview of the treatment of tannery effluents, segregation of streams, treatment of spent liming floats, and treatment of chrome-bearing floats
Module 2: Treatment within tannery compound. This refers to the pre-treatment for discharge into the common effluent treatment plant (CETP) collection network, and physical-mechanical (primary) treatment for discharge into municipal sewage.
Module 3: Sludge dewatering.  This module explores sludge thickeners, sludge pumps, filter press, centrifuge, belt filter press, flow-chart of physical-chemical treatment, and sludge drying beds.
Module 4: Biological (secondary) treatment.  This module looks into activated sludge, aeration devices, oxidation ditch, and the flow-chart of the biological treatment
Module 5: Occupational safety and health (OSH) in CETP, and its costing and management

Link to the course: https://learning.unido.org/course/view.php?id=6

Course: Occupational Safety and Health Aspects of Leather Manufacturing  - This training programme has been primarily designed for a wide range of people involved in the leather industry: from owners and tanners to managers and supervisors to tannery workers and technicians. Some parts of the training can be used by participants as self-study material. The training can also help in an exchange of ideas on how to improve the occupational safety and health standards at work in the tanneries and effluent treatment plants.

WHY IS SAFETY TRAINING IMPORTANT?

Safety training for employees is important because it reduces workplace injuries, boosts productivity, and creates a safer workplace. 

WHY DO STAFF NEED THIS COURSE?

Employers have a legal responsibility to provide key safety information to staff. Your staff need to understand Health & Safety basics in the workplace. The Health & Safety Awareness Course will deliver exactly that and provide your business with legal compliance.

WHO IS THIS COURSE FOR?

All practitioners involved in the leather industry but the core principles are applicable to all industries.

OBJECTIVES

This interactive course introduces the participant to many aspects of the Health & Safety at Work and is intended to help raise safety standards and awareness. Blended learning, group activities, case studies, etc will introduce key components and strategies to managing safety effectively.

COURSE CONTENT

The OSHALM Training is a blended learning programme which comprises classroom and online/self-paced components.

The course curriculum is structured into the following eight modules

COURSE BENEFITS

The Health & Safety Awareness Course is perfect for delivering safety awareness information to your staff.

Safety training is more than just a vital tool to keep your company compliant – it’s also an opportunity to foster a strong safety culture throughout the entire organization to make compliance the priority from the start.

Course link: https://learning.unido.org/course/view.php?id=141  

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.

Primitive tools made of stones and bones were the first equipment used for removing unwanted substances (fat, meat, hair) from the cured/conservated (by minerals) animal hides in order to protect the human foot and the body. For thousands of years only pits, various hand tools and simple machines were used in processing leather and making derived products such as shoes, gloves, bags, belts, harness and upholstery. With the gilds manufacturing processes were split into distinct operations that facilitated the construction of mechanisms and machines to assist manual workers or later to replace them. Mechanization of leather processing and leather products production started with the industrial revolution and accelerated by the invention of electric engines. Tanneries making leather from raw animal hides/skins use today heavy moving vessels (paddles, drums, mixers), mechanical and hydraulic equipment became a capital intensive and energy consuming industry. Nevertheless, basic principles of leather processing has not changed, automation made a limited impact on this industry. Chrome tanning will probably dominate leather making in the next decades, more and more through feed types of machines will be applied, but solid and liquid waste recycling or disposal remains the major problem of this trade. In spite of introduction of new and productive technologies (CAD/CAM, injection moulding etc.) leather products manufacturing is still a labour intensive industry. Future development is expected from robotization, further computerization, use of biotechnology and artificial intelligence. Use of commodities made of leather (derived from animal hides/skins) will be influenced by tendencies in meat consumption (raw hides/skins are by-products of the meat industry), achievements of the material science (development of synthetic leather substitutes having the same or even better hygienic and wear properties as leather) and additive manufacturing (e.g. 3D printing.) 

Safety doesn't happen by accident!

This Second Edition is a thoroughly revised and expanded version of UNIDO paper The Occupational Safety and Health Aspects of Leather Manufacture from 1999.This manual has been primarily prepared for use by tanners and tannery supervisors. It has been designed to provide guidance and ideas on how to improve the occupational safety and health standards at work in tanneries and effluent treatment plants by presenting the sources of hazards in a tannery and pointing out simple measures, in a practical and easily understandable manner, for ready implementation on-site. A special attention is given to risks associated with hydrogen sulphide gas, H2S. 

Course: Occupational Safety and Health Aspects of Leather Manufacturing is available here

APLF webinar on safety is available here

Recommendations and preventive measures in response to COVID-19: Guidance for the industrial sector

This tool provides guidance to employers, workers and their representatives on preventive measures for a safe return to work in the context of COVID-19, conforming to well established principles and methods on occupational safety and health risk management.

There are many other useful guidelines and recommendations available.

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