WET END: Soaking, liming/unharing, deliming & bating; Pickling & tanni Leatherbiz

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130 items found in WET END: Soaking, liming/unharing, deliming & bating; Pickling & tanning.

Downloadable PDF Over-complication
In the first in a series of articles that draw on his long, personal experience as a tanner, technical editor, Matthew Abbott, argues that the processes involved in making leather are difficult enough already. To add more complexity is to invite trouble.
World Leather - Dec/Jan 2020
Downloadable PDF Biocircular leather
Metal-free tanning has been used since the first hide was tanned. Modern advances in technology have improved the performance of the leathers but, in doing so, have limited the disposal routes of the leather and the end products. Silvateam believes it has now developed a tanning system, Ecotan, that allows for a “truly sustainable” and circular product that can be recycled into fertiliser and returned to the lifecycle of leather.
World Leather - Dec/Jan 2020
Downloadable PDF Smit & Zoon promises sustainable tanning solutions
With a long-established background in retannage, fatliquoring and syntans, Smit & Zoon, a seventh-generation, family-owned business based in the Netherlands, has strengthened its portfolio of products over recent years. In 2017 it acquired further wet-end and finishing proficiency with Codyeco, giving access to more fashion-based markets. In its latest technology launch, it has introduced new sustainable leather tanning solutions that it claims can be a gamechanger for the leather industry. World Leather spoke to Smit & Zoon chief executive, Hans van Haarst, about this development.
World Leather - Oct/Nov 2020
Downloadable PDF The yellowing problem: Causes and possible technical solutions
Light-coloured leather, especially leather with a white finish, falls within the category of materials used mainly for luxury and high-end products. For this type of article, the uniformity of colour and appearance of the overall surface are fundamental requirements demanded by major national and international fashion and luxury brands. This study aims to give an overview of all the main advanced diagnostic tools for identifying the causes of yellowing, with a view to offer manufacturers and users possible ideas for developing strategies to resolve and/or minimise the problem of yellowing.
World Leather - Aug/Sept 2020
Downloadable PDF Low chrome options for high exhaustion tanning
United Chemicals has developed the ProWhite Tanning System to add value to the leather industry by offering more environmental applications.. ProWhite are tanning processes without a pickling stage, carried out at neutral pH and are environmentally benign, significantly reducing the consumption of acids, bases, sodium chloride and water. The tanning system decreases the cost of waste streams for tanners due to the effective tanning action. Remaining amounts in the tanning bath pose no threat to the environment, and the clean and bright wastewater is easier to treat.
World Leather - Aug/Sept 2020
Downloadable PDF Unique wet end technologies offer sustainable competitive advantages in automotive leather
New schemes and technologies increasingly promise to give the car-less majority vehicle access and increase usage overall that will subject leather to higher wear. Key innovative wet end products and processes are covered from soaking to crusting to show how performance can be improved together with increased sustainability. A “critical mass” point has been reached where these products, combined together across wet end processing, are able to offer automotive leather producers not only individual solutions to technical challenges but coherent sustainable competitive advantages, already proven and adopted by leading tanneries, helping to keep leather relevant and supporting the future of our industry.
World Leather - Aug/Sept 2020
Downloadable PDF Chrome (VI) suppression - natural phenolics preventing ageing in leather
Gallic acid esters are a class of polyphenolics that have been found in previous work to be very suitable antioxidants for leather, securely preventing the formation of Cr (VI). In fact, alkyl gallates with long carbon chains have an efficiency that is far superior to tara or gallic acid. In this work we compare gallic acid derivatives with DL-tocopherol (Vitamin E) and tocopherol derivatives, discussing the results in antioxidant efficiency in leather in the framework of the polar paradox and the efficiency of the very phenolic groups. The final aim of this analysis is the improvement of sustainability of leather by increasing quality and durability of leather articles and a better protection against the formation of Cr(VI) by incorporating natural ingredients.
World Leather - Aug/Sept 2020
Downloadable PDF Smit & Zoon promises sustainable tanning solutions
With a long-established background in retannage, fatliquoring and syntans, Smit & Zoon, a seventh-generation, family-owned business based in the Netherlands, has strengthened its portfolio of products over recent years. In 2017 it acquired further wet-end and finishing proficiency with Codyeco, giving access to more fashion-based markets. In its latest technology launch, it has introduced new sustainable leather tanning solutions that it claims can be a gamechanger for the leather industry. World Leather spoke to Smit & Zoon chief executive, Hans van Haarst, about this development.
World Leather - Aug/Sept 2020
Downloadable PDF For a natural look
Seta S/A was the pioneer in Brazil in the production of acacia tannins with the start of its activities in 1941, in the city of Estância Velha / RS. Today, the company produces and markets mimosa wattle extracts worldwide, not only to produce leathers, but also for other uses such as water and wastewater treatment, animal nutrition, adhesives and dispersants. Another important factor regarding the production of these extracts is the fact that reforested trees are legumes and return to the soil some important nutrients, recovering areas for future acacia plantations or even other plant crops.
World Leather - Jun/July 2020
Downloadable PDF Evaluation of (re)tanning effect of leather chemicals in a model and a real system
A model system based on glycerol-containing gelatin films has allowed Smit & Zoon to assess the ability of various syntans to increase the shrinkage temperature and change the mechanical properties of leather.
World Leather - Apr/May 2020
Downloadable PDF The dynamics of leather combustion
Leather is a combustible material and must be treated with appropriate flameretardant products to pass fire-prevention testing. This is part one of a twopart article on this subject from Ikem. With more than 40 years’ experience of offering beamhouse, tanning, retanning and finishing products to the global leather industry, Ikem became part of the GSC group at the start of 2019.
World Leather - Oct/Nov 2019
Downloadable PDF Driving leather innovation
On a recent visit to its main production site at Dongen in the Netherlands, World Leather had the opportunity to look behind the scenes at Ecco Leather and see why the company is a driving force of leather innovation.
World Leather - Aug/Sept 2019
Downloadable PDF Sustainable sourcing of tannins
In this article, Italian chemicals manufacturer Silvateam offers more details about how it sources sustainable tannins, and its use of quebracho from Argentina and of tara from Peru. In the previous issue of World Leather, it focussed on its sourcing of chestnut tannins from Italy.
World Leather - Jun/July 2019
Downloadable PDF Tannins: a sustainable solution
In the first of two articles, Italian chemicals manufacturer Silvateam offers insight into sources of sustainable tannins from areas of Italy and South America. The second article will contain information about its use of quebracho from Argentina and tara from Peru. This paper focuses on its efforts to source chestnut tannins from Italy in a manner that respects the environment while also supporting the economic growth of local rural areas.
World Leather - Apr/May 2019
Downloadable PDF Hides go to waste
Demand for high-quality leather remains strong, but no one in the global industry can be in any doubt that lower-value material is harder to sell than at any time in living memory. As a result, what we thought would never happen has come to pass: hides really are going to waste.
World Leather - Apr/May 2019
Downloadable PDF Taking tanning to the next level with an improved pickle product
Although chrome tanning is already at what leather chemicals manufacturer Lanxess calls “a high level of performance”, it explains that it is working to make further improvements to this tanning method.
World Leather - Apr/May 2019
Downloadable PDF Mercier Turner augments its Newsplit machine
Since World Leather last published information about the Newsplit splitting machine from French tanning machinery provider Mercier Turner in 2015, the company has continued to make progress on a seven-year project to refine and improve lime-splitting capabilities.
World Leather - Feb/Mar 2019
Downloadable PDF LIFE Biopol project moves out of the laboratory
During the 2019 India International Leather Fair (IILF) in Chennai, World Leather sat down with commercial director wet end for Smit & zoon, Arnaud Backbier, to discuss the LIFE Biopol project that the company has been involved with through Codyeco, the Italian leather chemicals producer it acquired in 2017.
World Leather - Feb/Mar 2019
Downloadable PDF Elimination of wastewaters from liming/unhairing and chrome tanning in wet blue manufacture
This paper concerns a radical new approach to the unhairing/liming and chrome tanning processes for wet salted bovine hides. The technology - developed by BIOSK Chemicals, China - was presented at the 11th Asian International Conference of Leather Science and Technology (2018), Xi’an. These techniques, as used by four major tanneries in China, are described in detail where major savings in chemicals and water are being made. In addition, major environmental issues arising from traditional methods of leather making are being avoided.
World Leather - Dec/Jan 2018
Downloadable PDF Soaking of bovine hides and its control in the tannery
Tanners can pay a heavy price for paying too little attention to soaking bovine hides. Mistakes at this stage produce faults that cannot be corrected later.
World Leather - Dec/Jan 2018
Downloadable PDF Generating consistent leather splits for footwear
Tanning technology provider Gemata has said the Starsplit splitting machine it developed and introduced to the market in 2017 can bring about a revolution in the lime-splitting process. This could be very good news for tanners but equally so for the large number of footwear brands interested in using leather splits in the shoes they are preparing for the coming seasons.
World Leather - Oct/Nov 2018
Downloadable PDF Salt and acid-less tanning system from Buckman
Buckman has developed technology that it claims can eliminate the pickling and basification stages in chrome-tanning.
World Leather - Apr/May 2018
Downloadable PDF Salt and acid-less tanning system from Buckman
Buckman has developed technology that it claims can eliminate the pickling and basification stages in chrome-tanning.
World Leather - Apr/May 2018
Downloadable PDF Boron in hide and skin curing processes
With the prevalence of tannery effluent being used for irrigation, tanners need to be aware of the specific monitoring requirements pertaining to soil and water sources as this article about boron illustrates.
World Leather - Dec/Jan 2017
Downloadable PDF Closed-loop liming and chromium tanning systems in industrial practice
Chinese leather chemicals manufacturer Biosk continues to roll out its system for offering tanners closed-loop liming and chrome-tanning procedures, in which floats can be reused time and time again.
World Leather - Dec/Jan 2017
Downloadable PDF Gemata introduces revolutionary splitting machine
We take a closer look at Gemata’s Starsplit splitting machine, which has features that include a newly developed automatic feeder system.
World Leather - Oct/Nov 2017
Downloadable PDF The difference between an interesting invention and a disruptive innovation
Lanxess’s Dietrich Tegtmeyer examines what makes a true innovation with reference to a fully automated plant for converting shavings into retanning chemicals being tested at Heller-Leder tannery in Germany.
World Leather - Aug/Sept 2017
Downloadable PDF Formaldehyde and acetaldehyde on leather: similarities and discrepancies
BASF presents new emission data that could help to minimise formaldehyde in leathers.
World Leather - Aug/Sept 2017
Downloadable PDF Stahl’s Centre of Excellence focuses on apparel and furniture
World Leather reports on the opening of Stahl’s new Centre of Excellence dedicated to apparel and furniture in northeastern Spain.
World Leather - June/July 2017
Downloadable PDF Developments in fatliquoring
At February’s IULTCS Congress in Chennai, Dirick von Behr, technical manager for leather at chemicals manufacturer Smit & zoon, presented a paper entitled “Method for determining the optimised exhaustion of fatliquors to minimise the ETP-inflow”. The paper referenced the upcoming changes in German regulations for the treatment of tannery wastewater. World Leather sat down with Mr von Behr to find out more.
World Leather - Apr/May 2017
Downloadable PDF Polycarbodiimides as classificationfree and easy to use crosslinkers for water-based coatings
A new family of VOC-free polycarbodiimides in aqueous delivery form is providing an alternative way of delivering crosslinkers for water-based coatings.
World Leather - Apr/May 2017
Downloadable PDF Tackling “veininess”, Part two
The second and final part of a paper from Lanxess examining the best strategy for addressing the problem of veininess in hides. The first part appeared in World Leather December 2016-January 2017.
World Leather - Feb/Mar 2017
Downloadable PDF greenLIFE 2: A novel Key Performance Indicator for the assessment of the liming process
Green Leather Industry for the Environment (greenLIFE) is a project run by a group of industry partners in Italy’s Arzignano tanning cluster. The project partners have committed to sharing their findings by publishing a series of papers in World Leather. This is the second of six greenLIFE articles.
World Leather - Feb/Mar 2017
Downloadable PDF greenLIFE 1: Oxidative liming
In 2014, two of the biggest tanners in the Arzignano cluster, Gruppo Dani and Gruppo Mastrotto, formally launched a joint project called Green Leather Industry for the Environment (greenLIFE), on which they have worked with three technical partners: chemical supplier Ikem, biotechnology firm Ilsa and the cluster’s wastewater treatment service provider, Acque del Chiampo. It has the aim of promoting sustainability in the tanning industry. Half of the funding for greenLIFE came from the European Union, which has asked the project partners to share their findings with the wider leather industry. The partners have picked World Leather as the ideal platform on which to publish the results of greenLIFE. This paper, the first of six World Leather will publish in the course of 2017, kicks the series off.
World Leather - Dec/Jan 2016
Downloadable PDF Improving the biodegradability of vegetable tanned leather
Tanning stabilises protein, thus making leathers more difficult to biodegrade than raw hides and skins, composting offers a solution to waste disposal problems associated with these leather products. In this event this offers a strong alternative to land-fill disposal or incineration of waste.
World Leather - Dec/Jan 2016
Downloadable PDF ReVeal – the Dutch veal and calfskin industry opens its doors
Leather chemicals manufacturer Stahl hosted a one-day event called ReVeal last November. The aim was to give finished product brands up-to-date information about transparency and traceability in the leather supply chain, with the focus firmly on Dutch calf leather.
World Leather - Dec/Jan 2016
Downloadable PDF Chamois leather process based on rubber seed oil, and rationalisation of the oxidation stage
Chamois leather has unique uses, including high quality gasoline filtration, gloves, garments, and cleaning and drying of optical equipment, spectacles, windows, vehicle, jewellery, and silverware. Indonesia is a rubber producing country with the largest rubber plantations in the world. Here, it produces rubber seeds from about 1,500 kg/hectare of land, and this resource has not been utilised optimally. It was considered that rubber seed oil could be used for chamois leather tanning, and an investigation took place to see if: [1] rubber seed oil could be used as chamois leather tanning agent [2] the time consuming oxidation stage could be rationalised.
World Leather - Oct/Nov 2016
Downloadable PDF A radical new approach within liming and chrome tanning technologies
A revolutionary approach to liming and tanning practices has been successfully developed by BIOSK (SQ) Chemicals, China. Concentrated floats from liming and tanning are retained in self-contained cycles and reused in processing.
World Leather - Aug/Sept 2016
Downloadable PDF Studies on the determination of soilingand cleaning behaviour of leather. Part 2: Inter-laboratory tests with specificreference concerning the cleaning step
In Part 1 of this study, published in World Leather February/March 2016, inter-laboratory tests enabled a closer view on the test procedures on soiling and cleaning behaviour of leather and their impact on the final result.
World Leather - June/July 2016
Downloadable PDF The influence of syntans on the assembly of collagen
Since the introduction of the first syntan one hundred years ago by BASF, the role of syntans in the tanning process has changed significantly. While syntans were initially used as dispersers and accelerators for vegetable tannins, they were applied as sole tanning agents later, and with the wide acceptance of chromium or glutaraldehyde tanning, they are now mainly used in the re-tanning process.
World Leather - Apr/May 2016
Downloadable PDF Studies on the determination of soiling and cleaning behaviour of leather. Part 1: Inter-laboratory test on soiling and cleaning behaviour of leather
A main task of the VGCT Commission “Leather Testing and Assessment” is the detailed examination for the determination of physical and colour fastness properties of leather, especially in terms of procedures. The intention is to detect performance characteristics of the procedures and to reveal and eliminate possible sources of error. Due to the trend for light-coloured leather for upholstery in the automotive and furniture sector, the soiling and cleaning behaviour of leather and its determination gain in importance. From the multiplicity of available test procedures for the characterisation of soiling and cleaning behaviour, the procedure VDA 230-212 was chosen and considered closely by means of an inter-laboratory test programme. In the context each procedural step was examined closely with regard to their impact on the final result of the test. Part 1 presents the results of the inter-laboratory test on soiling and cleaning behaviour of leather. Part 2 (to be published in World Leather later in 2016) will deal with the validation of an optimised mechanical cleaning step.
World Leather - Apr/May 2016
Downloadable PDF Glutaraldehyde: Proven technology for white metal-free leathers Part 2 of 2: The versatility of glutaraldehyde in leather making
Part 1 of this paper, published in December/January 20015/16 and entitled Pre-tanning with modified glutaraldehyde, describes the theory and practice of glutaraldehyde tanning, ecological and toxicological aspects, and pre-tanning including a guideline formulation. In this paper, Part 2, the study expands upon the versatility of this product, and includes two guideline processes for the retannage and fatliquoring of automotive and footwear leathers.
World Leather - Feb/Mar 2016
Downloadable PDF Glutaraldehyde: Proven technology for white metal-free leathers Part 1of 2: Pre-tanning with modified glutaraldehyde
The theory and practice of glutaraldehyde tanning Glutaraldehyde first received attention as a tanning agent in the 1960s. For monoaldehydes, the higher homologous species a reprogressively less effective tanning agents than formaldehyde. In general, the same applies to dialdehydes in relation to the smallest example glyoxal. However, glutaraldehyde is an exception to this rule as it is a very efficient tanning agent.
World Leather - Dec/Jan 2015
Downloadable PDF SLTC 117th Annual Conference / The Mary Rose
The 118th Annual Conference of the SLTC was held at The University of Northampton 25th April 2015. The event was attended by 79 delegates, and was followed in the evening by the SLTC Annual Dinner Dance.
World Leather - June/July 2015
Downloadable PDF Perceptions of chrome and chrome-free tanning systems by Silvateam, Italy
The findings are based on the opinions of a considerable range of tanneries producing chrome tanned, chrome tanned and chrome-free, and vegetable tanned leathers.
World Leather - Apr/May 2015
Downloadable PDF Perceptions of chrome and chrome-free tanning systems by Silvateam, Italy
The findings are based on the opinions of a considerable range of tanneries producing chrome tanned, chrome tanned and chrome-free, and vegetable tanned leathers.
World Leather - Apr/May 2015
Downloadable PDF Sustainable tanning: waste minimisation in the tannery
Over the last few years the chemical industry has introduced many new technical solutions to the leather industry. Most offer environmental advantage or reduced risk of harm, and these advances are set to continue. In particular, novel enzymatic beamhouse systems and new wet white technologies are two major wet-end process steps where developments have been focused. Advances in these areas will lead to more sustainable leather articles and process conditions with a lower environmental impact.
World Leather - Apr/May 2014
Downloadable PDF Hybrid chrome tannage coupled with recycling for minimisation of residual chrome from tanning
Today, 80-90% of leathers in the world are tanned with chrome. The increasing requirements of producing safe leathers in a sustainable way have led Silvateam to develop a new technology that permits: • Increase the fixation of chrome oxide to the leather fibres; • Minimise the use of chrome salts in the tanning processes; • Reduce the chrome content in wastewaters.
World Leather - Feb/Mar 2014
Downloadable PDF Somalia: The Berbera Tannery
The region that today encompasses Somaliland was home to the earliest civilization in the region. The most salient feature of this ancient civilization is thought to be the Laas Geel Neolithic cave paintings, which are among the oldest such rock art in Africa. These cave paintings are located in a site outside Hargeisa, the capital of the Somaliland region, and were untouched and intact for nearly 5-10,000 years until their recent rediscovery at the end of 2002.
World Leather - Dec/Jan 2013
Downloadable PDF Flame resistant leathers for the aviation industry
Clariant: There is a demand for flame retardancy, and a new approach based on EasyWhite Tan achieves these critical specifications as well as meeting the need for secure and environmentally friendlier ingredients and processes.
World Leather - Dec/Jan 2013
Downloadable PDF Flame resistant leathers for the aviation industry
Clariant: There is a demand for flame retardancy, and a new approach based on EasyWhite Tan achieves these critical specifications as well as meeting the need for secure and environmentally friendlier ingredients and processes.
World Leather - Dec/Jan 2013
Downloadable PDF Oxidative unhairing
The following overview by R.P.Daniels is based on: • Presentations: G.A.Defeo, Ars Tinctoria SRL (Italy), and S.Dani, Italprogetti Engineering (Italy): LGR, Reutlingen 2011 and Freiberg Leather Days April 2012. • G. Defeo, ARL Tinctoria,: SLTC Conference Northampton 2013. • Information from: Gruppo Dani, Arzignano, Italy 2012 and Italprogetti, Italy 2013.
World Leather - Oct/Nov 2013
Downloadable PDF X-Zyme – a novel beamhouse technology
In a partnership for the tanning industry, Novozymes and Lanxess are combining patented biotechnology with chemical and global processing know-how. The two companies are introducing a novel beamhouse process that delivers high-quality pelts and significantly improved effluents.
World Leather - Aug/Sep 2013
Downloadable PDF How a new approach to the tannery drum developed
A historical look at the evolution of the drum and of Swiss tannery Huni.
World Leather - Feb/Mar 2013
Downloadable PDF Tannery machinery accessories and spare parts from Italy
Providing the many leather producers clustered in the leather centres of Italy with a just-in-time specialist service, spares and an array of auxiliary devices has created a huge marketing opportunity for the small but technically qualified enterprise.
World Leather - Feb/Mar 2013
Downloadable PDF A modern semi-rapid vegetable tanning with high exhaustion
A new approach to vegetable tanning has been developed that brings together the technical advantages of both pit and drum vegetable tanning systems. The system operates with a very high uptake of vegetable tannins, and eliminates the need for common salt in the pickle stage that normally precedes drum tannage.
World Leather - Dec/Jan 2012
Downloadable PDF A new green leather
As a result of close cooperation between N-Zyme BioTec and LGR, a tanning process has been developed and optimised on bovine hides using activated olive residues.
World Leather - Apr/May 2012
Downloadable PDF Machines in the Tannery: Innovators & Research - Turner
The core business of the company is the production of classic tannery machinery, including fleshing, setting and shaving machines.
World Leather - Feb/Mar 2012
Downloadable PDF X-Tan – new leather qualities by sustainable organic tanning
This paper describes an innovative organic tanning system suitable for a wide range of leather articles. The system is not based on metal salts or aldehydes and produces a very white and stable intermediate. As the pickle step is no longer necessary and any potential excess tanning agent hydrolyzes to toxicologically uncritical products, both the effluent and the resulting shavings present tangible advantages to the tanner.
World Leather - Oct/Nov 2011
Downloadable PDF Today’s view on vegetable extracts in wet-end processing
Vegetable tannins are compounds of vegetable origin from various parts of trees and plants. They have been known and used by tanners for over two thousand years, but until the 19th century they were mainly used in the form of raw, untreated material such as bark. Then chemical companies began to increase the tanning content yield by extraction using an autoclave followed by spray drying. This resulted in extracts such as chestnut or mimosa with more than 70% concentrated tanning power.
World Leather - Oct/Nov 2011
Downloadable PDF Vegetable tannins are compounds of vegetable origin sustainable organic tanning
This paper describes an innovative organic tanning system suitable for a wide range of leather articles. The system is not based on metal salts or aldehydes and produces a very white and stable intermediate. As the pickle step is no longer necessary and any potential excess tanning agent hydrolyzes to toxicologically uncritical products, both the effluent and the resulting shavings present tangible advantages to the tanner.
World Leather - Oct/Nov 2011
Downloadable PDF Studies on assembly and de-assembly of collagen
Collagen type I is the main component of skin. There are still unanswered questions in the mechanism of tanning that make it necessary to continue research on this topic. There is a need to understand tanning more clearly, or rather the interaction between collagen and tanning agent.
World Leather - Oct/Nov 2011
Downloadable PDF Balancing innovation with commercial reality
In today’s commercial world, innovation usually results from a ‘what if ’ or ‘can we get rid of a problem’ discussion. Innovation for innovation’s sake is a luxury that many major companies, with multiple stakeholders, simply cannot afford, although it won’t necessarily prevent an individual pursuing an idea.
World Leather - Oct/Nov 2011
Downloadable PDF The roots of raw material
National Beef’s ambition to make its wet blue plant in Missouri an example for the whole industry is well on the way to becoming true.
World Leather - Oct/Nov 2011
Downloadable PDF Wet-green leather: the ultimate green tannage
A new tanning system has moved from concept, through the development stages and now into manufacture on production scale. Based on initial development work by Lederinstitut Gerberschule Reutlingen in conjunction with N-Zyme BioTec GmbH, this new tannage has been turned into a practical reality by Heller-Leder.
World Leather - Oct/Nov 2011
Downloadable PDF Innovation Part 1: Recycling and regeneration
Twenty world standard tanneries have opened their doors for in-depth study as part of Tannery of the Year Awards 2009 and 2011. Considerable technical information has been published in World Leather following these visits, and there has been an emphasis on environmental aspects. This article is the first in a series that picks out some of the highlights from the innovation stories these top tanneries have shared with us.
World Leather - Oct/Nov 2011
Downloadable PDF Innovation Part 1: Recycling and regeneration
Twenty world standard tanneries have opened their doors for in-depth study as part of Tannery of the Year Awards 2009 and 2011. Considerable technical information has been published in World Leather following these visits, and there has been an emphasis on environmental aspects. This article is the first in a series that picks out some of the highlights from the innovation stories these top tanneries have shared with us.
World Leather - Oct/Nov 2011
Downloadable PDF Test method for the determination of chromium (VI) in tanning agents
Details of a test method for detecting the presence of chromium (VI) in chrome tanning agents, developed by Dr Ute Morgenstern and Dr Haiko Schulz of FILK.
World Leather - Aug/Sep 2011
Downloadable PDF Relationships in the formation of hexavalent chrome [Cr(VI)] (Part 2)
Leather research institutes have examined the occurrence of toxic materials in a variety of chrome leathers and leather articles for many years. The Health & Safety department of the German government has shown that some leather goods - such as gloves, shoes and watchstraps - can contain Cr(VI) in significant quantities. The federal authority has decided to prohibit Cr(VI)for leathers in daily use.
World Leather - Jun/Jul 2011
Downloadable PDF EasyWhite Tan leather: A tanning evolution
This paper describes a new white tanning system from Clariant for leathers suitable for automotive, shoe upper and other classic leather types. The absence of common salt as normally used in the pickle stage has significant implications within clean technology and the wider environment.
World Leather - Feb/Mar 2011
Downloadable PDF Deep shelf/slow speed processing vessels
Drums fitted with deep shelves and rotating at relatively slow speeds for wet processing hides into leather were first brought into use in the mid-1990s. Since that time the technology has evolved, and they are now being used for soaking, liming, tanning and retanning/dyeing.
World Leather - Dec/Jan 2010
Downloadable PDF Chrome and veg-tanned leathers from a footwear perspective
Tanners have become increasingly frustrated by the way in which the use of chrome has been presented to the public in general. It is high time that its continued usage or replacement by vegetable tanning agents was examined in a less hysterical and alarmist manner.
World Leather - Aug/Sep 2010
Downloadable PDF Small moulds can cause big problems
Asignificant cause of loss in value in leather processing is due to fungal or bacterial growth, and even biocidal agents fail in certain cases. These small microorganisms are not visible to the naked eye, and are normally only identified when the defect reaches a certain level.
World Leather - Aug/Sep 2010
Downloadable PDF The formation of volatile organic compounds (VOC) and hexavalent chrome in chrome tanned leather
Following a remarkable number of recent customer enquiries regarding the mechanism of the formation of VOCs, as determined by head space analyses, it was decided to re-examine this important subject in connection with hexavalent chrome formation.
World Leather - Apr/May 2010
Downloadable PDF The mechanisms of effective soaking: Fresh and brine-cured hides
The soaking of fresh cattle hides differs from the soaking of salted or brine-cured cattle hides. This paper reveals the differences between these two types of raw material, including the relationship between hyaluronic acid extraction from the hide into the float and effective soaking, and other related issues.
World Leather - Feb/Mar 2010
Downloadable PDF Benchmarking: Part 4
Three papers have been published in World Leather setting down various aspects of Benchmarking. 1) Benchmarking: a comparison with the best in the sector in Oct 2008. 2) Benchmarking: A tannery model for comparison in Nov 2008. 3) Benchmarking: overall materials balance in conventional tanning in Dec/Jan 2008/9. The following information provides benchmark values for pollution and the performance in conventional tannery processing.
World Leather - Feb/Mar 2009
Downloadable PDF Attaining Zero effluent discharge: Presidency Kid Leathers, India
In the State of Tamil Nadu, India, it is mandatory that all tanneries have a reverse osmosis (R.O.) plant and achieve zero discharge of effluent from the site. If tanners do not comply with this legislation they will not be licensed to run the tannery. Furthermore, all Common Effluent Treatment Plants now have to follow this policy..
World Leather - Feb/Mar 2009
Downloadable PDF Benchmarking: Part 3
OVERALL MATERIALS BALANCE IN CONVENTIONAL TANNING
World Leather - 08 - Dec/Jan 2008
Downloadable PDF The extraction and profile of Mimosa
Although vegetable extract usage in leather manufacture has declined over the years, mainly due to the fall-off in demand for heavy veg leather, there is still a substantial use of the three main extracts, Mimosa (or Wattle/Acacia), Quebracho and Chestnut. Also, because of its good light fastness properties, Tara is experiencing an increase in demand for automotive upholstery leather. Strap and case leather tanned with vegetable extracts remains buoyant, and vegetable retanning of chrome leather has gained in importance with the swing to more ‘natural’ leathers.
World Leather - 06 - Oct 2008
Downloadable PDF The chemical reactivity control of collagen: The Hofmeister Effect revisited
The Hofmeister effect concept was noted over a century ago. This concerns the action of certain ions in the solubility character of some colloids due to the partial breaking-up of the internal helical structure. Stabilising salt-linkages between charged protein side-groupings are broken, which in turn makes more charged groups available. In the case of collagen, these effects can be employed to gain improved reactions with tannage-related chemicals.
World Leather - 03 - May 2008
Downloadable PDF Improving the traditional vegetable tanning process
Vegetable tanned leathers are typical of the high-quality leathers produced within the tanning district of Santa Croce sull’Arno, Italy. This is the oldest and most classic type of leather, combining the values of quality and tradition.
World Leather - 01 - Feb/Mar 2008
Downloadable PDF Carbon dioxide deliming of full thickness hides
In World Leather May 2007, a list was given of 45 papers that had been published which addressed various aspects of salinity that arise from leather manufacture. To make the compendium as complete as possible, some papers that were still awaiting publication were also included. This was an unusual step but, with consideration to the growing environmental pressures that tanners are facing, and to make the compendium comprehensive, it was considered right to include this material. The following is one of the papers that was awaiting publication, and concerns the use of carbon dioxide as a proven method of reducing the total dissolved solids (TDS) content of wastewaters. CSIRO was at the forefront in the investigation of this technology and its introduction into commercial use. When reading this paper, it should be remembered that the original report was produced in the early 1990s and, as it has only been subject to a very light edit, some minor details will have now changed. The information set down is, however, fundamental to the highly successful technology and this is probably the most informative study written on this subject.
World Leather - 01 - Feb/Mar 2008
Downloadable PDF The scientific and commercial significance of variations in strength and stretch in leather
Any variations in physical properties—especially the degree of stretch under load and the tensile strength—need to be accommodated within a manufactured item to both extract the best value from the leather and, in the longer term, to ensure customer satisfaction. This applies to almost all items manufactured from leather—garments, leather goods, furniture, automotive components, and footwear—as there is a need for shape retention during wear and use.
World Leather - 07 - Nov 2007
Downloadable PDF The theory and practice of direct pickle/chrome liquor recycling
Minimising the chloride/sulfate and chromium ion content from pickle tanning Although the information set down in this paper is fundamental to the highly successful technology and this is probably the most informative study that has been written on this subject, it should be remembered that the original report was produced before the technology became widely established and some minor details will have changed by now.
World Leather - 06 - Oct 2007
Downloadable PDF The determination of chromium (VI): Standardisation status
The co-existence of two different procedures for determining hexavalent chromium in leather across Europe has placed this hazardous substance once more in the midst of controversy.
World Leather - 06 - Oct 2007
Downloadable PDF The application of modern biotechnology methods and the manufacture of quality leathers
The increased use of biotechnology methods by leading chemical supply companies is impacting the way that leather is produced today. Changes have resulted in improvements to the repeatability of processing, reductions in cost, and a decrease in the environmental footprint along with improvements in leather quality.
World Leather - 05 - Aug/Sept 2007
Downloadable PDF The soaking, unhairing and liming process – Part 3 of 3: Managing the process formulation
In Parts 1 and 2 of this three-part series, detailed guidelines for the successful soaking and unhairing/liming of bovine hides were presented, but there is a problem in practical manufacture. Not only are these initial steps in leather-making the foundation of good quality leather, but the appearance of hides and skins after unhairing and liming is difficult to relate with the final leather.
World Leather - 05 - Aug/Sept 2007
Downloadable PDF Collagen as a substrate for biomaterials: Part 1
Using advanced biotechnology, it is possible to cut specific regions of the collagen molecule in order to solubilise collagen whilst, at the same time, retaining its helical nature. This new form of collagen can then be precipitated from solution, solubilised and moulded into any shape or form that may be required.
World Leather - 05 - Aug/Sept 2007
Downloadable PDF Formaldehyde analysis: Test methods and results
There have been recent changes in the understanding of the toxicity of formaldehyde, and a proposed change in the testing method. With the realisation that the greatest risk to human health comes from airborne formaldehyde, test methods are now tending to change to reflect this.
World Leather - 03 - May 2007
Downloadable PDF The practicalities of the unhairing/liming process. Part 2 of 3
This second paper provides detailed information on the key aspects that underpin good practice within commercial unhairing/liming systems.
World Leather - 02 - April 2007
Downloadable PDF Chrome tanning process without a float and with low salt content
The convential chrome tanning process results in significant pollution of wastewaters. To reduce these effects an investigation has been undertaken that involves a pickle without a float and the minimum level of salt.
World Leather - 02 - April 2007
Downloadable PDF The soaking, unhairing and liming process: Part 1 of 3
The practicalities of the soaking process.
World Leather - Nov 2006
Downloadable PDF Neutralisation: the key to successful retannage, dyeing and fatliquoring
The main purpose of the neutralisation process in the production of chrome-tanned leathers is to reduce the acidity throughout the hide or skin structure. This is to enable the retanning, dyeing and fatliquoring processes to be carried out successfully. In chrome leathers, pH values usually range from 3.0 to 4.0, and this is far too acidic to allow penetration of anionic products. Neutralisation increases the leather pH to levels that are generally between pH 4.2 and 6.5.
World Leather - Oct 2006
Downloadable PDF Automobile leather manufacture: Part 1
The prospects and limitations of organic tanning.
World Leather - Aug/Sep 2006
Downloadable PDF Technologies to improve the useful area of leather
The manufacturing of leather is facing diverse challenges including pressure from the eco-toxicity point of view, in the form of stringent new regulations. The measures necessary to deal with these issues add to the cost pressure that tanners are experiencing.
World Leather - Aug/Sep 2006
Downloadable PDF Technologies to improve the useful area of leather
The manufacturing of leather is facing diverse challenges including pressure from the eco-toxicity point of view, in the form of stringent new regulations. The measures necessary to deal with these issues add to the cost pressure that tanners are experiencing.
World Leather - Aug/Sep 2006
Downloadable PDF Microbiological testing of leather
Growing competition from lower cost countries in the Far East has forced the predominantly small- and medium-sized enterprises that comprise Europe's footwear industry to adopt innovative features and optimise comfort. One area to receive increased attention is the microbial resistance of upper leathers and, as a consequence, the test methods used to ensure their quality in this respect.
World Leather - June/July 2006
Downloadable PDF A salt-free pickling regime for hides and skins
This paper describes a series of pilot studies to investigate salt-free pickling systems based on phenol sulfonic acid preparations on hides, sheepskins pelts, and woolsheep leading to the successful commercialisation of the findings.
World Leather - June/July 2006
Downloadable PDF The potential of silicates in leather production: Part 4 of 4
Research into leather-related silicon chemistry.
World Leather - June/July 2006
Downloadable PDF Observations: the suppression of swelling
The suppression of swelling in acid-pickle using alternative salts to common salt.
World Leather - June/July 2006
Downloadable PDF The potential of silicates in leather production. Part 2
Benefits with new chemical procedures, and the development of a new commodity.
World Leather - April 2006
Downloadable PDF Vegetable tannage of heavy leathers
Over and above the type of skin or hide, the characteristics of vegetable tanned heavy leathers are highly dependent on the nature of the vegetable tanning material selected; the percentage of tannin offered; and the levels of acids and salts in the tannage.
World Leather - April 2006
Downloadable PDF Otzi died with his boots on
In 1991 a deep frozen corpse was discovered at 3,210 metres on top of a mountain on the border between Austria and Italy. He has been nicknamed Otzi and has been the subject of intense scientific research. The ancient footwear fascinated Petr Hlavacek from Zlin's Thomas Bata University who has reconstructed Otzi's boots.
World Leather - Feb/Mar 2006
Downloadable PDF The potential of silicates in leather production. Part 1
Salt-free curing of hides and skins and reducing the salt content of tannery effluents.
World Leather - Feb/Mar 2006
Downloadable PDF Protein and leather charge
A study of the charge of collagen/leather depending on the relationship between pH and pI.
World Leather - Dec/Jan 2005
Downloadable PDF The real cost of a kilo of salt
The following paper provides an overview of a different approach to tanning. The technique is managed in the ‘non-swelling’ pH zone, and thus eliminates the need for salt within the conventional acid pickle. The fibre stabilisation provided – somewhat similar to a pretannage with glutaraldehyde – allows strong leather characteristics, such as those provided by conventional chrome tannage, to be developed within a main tanning or retanning stage.
World Leather - Nov 2005
Downloadable PDF Optimum chrome tanning of hides and modified Thrublu process for lime-split hides
Chrome tanning for a long time enjoyed a unique position amongst tanners and almost 90% of leather produced is chrome tanned. A number of studies have been published suggesting that Chromium(III) itself may be toxic at higher levels and Chromium(VI) is a known carcinogen. So, tanners have to consider how best to modify their tanning process for better exhaustion of chrome and look for alternative means to minimise the impact of tanning on the environment.
World Leather - Nov 2005
Downloadable PDF Optimum chrome tanning of hides and modified Thrublu process for lime-split hides
Chrome tanning for a long time enjoyed a unique position amongst tanners and almost 90% of leather produced is chrome tanned. A number of studies have been published suggesting that Chromium(III) itself may be toxic at higher levels and Chromium(VI) is a known carcinogen. So, tanners have to consider how best to modify their tanning process for better exhaustion of chrome and look for alternative means to minimise the impact of tanning on the environment.
World Leather - Nov 2005
Downloadable PDF Back to Basics: Modifying the skin structure & Hides and skins and mechanical forces
Essay 1: Before first-time drying and the formation of a flat stable substrate, the conversion of hides and skins into leather can be viewed as two distinct stages: the removal of unwanted skin components and the location of specific materials within the collagen structure. Essay 2: The role of the process vessel in leather manufacture is greater than that of a chemical reactor. While chemical reactions take place, considerable forces are applied to the goods undergoing process. The way these forces are received, and the outcome, strongly affects the chemical distribution within each hide or skin.
World Leather - Nov 2005
Downloadable PDF Removing phospholipids from hides: Looking back on a “New perspective on wet processing”
The paper "New perspective on wet processing" was published in World Leather October/November 1993, in which the advantages offered by the removal of phospholipids were discussed. Given that the value of raw hides and leather selling prices - strongly influenced by area and quality - are so important to the tanner, perhaps it's time to re-evaluate this technology.
World Leather - Oct 2005
Downloadable PDF The diffusion barrier within the unhairing process
World Leather takes a look at the hair-saving processes for bovine hides that are being applied in tanneries in several countries to replace traditional hair burning systems.
World Leather - Oct 2005
Downloadable PDF Hides and skins: Temperature and physical change
This article takes a look at the profound influence temperature has on the physical properties of hides and skins within every stage of leather manufacture.
World Leather - Aug/Sep 2005
Downloadable PDF Hides and skins: Temperature and physical change
This article takes a look at the profound influence temperature has on the physical properties of hides and skins within every stage of leather manufacture.
World Leather - Aug/Sep 2005
Downloadable PDF Hides and skins: Physical change and effects within chemical processing
The forces applied to skins in wet chemical processing relate to the type of processing vessel and its internal configuration. These forces can be viewed as constant when processing at uniform loadings, float levels, speed of rotation and time. We take a look how the way these forces act will vary as the skin physically changes.
World Leather - Aug/Sep 2005
Downloadable PDF Hides and skins: Physical change and effects within chemical processing
The forces applied to skins in wet chemical processing relate to the type of processing vessel and its internal configuration. These forces can be viewed as constant when processing at uniform loadings, float levels, speed of rotation and time. We take a look how the way these forces act will vary as the skin physically changes.
World Leather - Aug/Sep 2005
Downloadable PDF A practical alternative to salt for the preservation of hides and skins
Salt as a preservative for hides and skins is simple in application, low in cost and effective. Accordingly it is the most common form of preservation, but in practical term salt cannot be removed within effluent treatment. It enters the environment where the true costs are experienced in reality.
World Leather - May 2005
Downloadable PDF A practical alternative to salt for the preservation of hides and skins
Salt as a preservative for hides and skins is simple in application, low in cost and effective. Accordingly it is the most common form of preservation, but in practical term salt cannot be removed within effluent treatment. It enters the environment where the true costs are experienced in reality.
World Leather - May 2005
Downloadable PDF The real cost of a kilo of salt: Part 1
The first part of two looks at salinity in the tanning process: responsibility and actions, and the elimination of salt from acid pickles.
World Leather - May 2005
Downloadable PDF The use of non-swelling acids in pickle to minimise the chloride content in wastewaters
In our industrialised society, responsibility for environmental protection is becoming more and more important. Not surprisingly environmental awareness has grown in leather production as it has elsewhere. Tough official regulations
World Leather - Feb/Mar 2005
Downloadable PDF The role of bound and free water in the liming process
In World Leather August/September 2004, observations were presented showing that if limed hides were washed at different temperatures, a warmer wash caused an increase in softness and hide relaxation, but without change in the total water content. References were made to earlier investigations that address aspects that need taking into account. Translations and detailed studies of these reports are summarised in the following paper.
World Leather - Dec/Jan 2004
Downloadable PDF Bating: gaining area while retaining cutting values
It is almost 100 years since Otto Röhm introduced the first industrial application of an enzymatic product. This was the bating process of animal hides within leather production, the enzymes being derived from pancreatic glands. This can be seen
World Leather - Oct 2004
Downloadable PDF Bating: gaining area while retaining cutting values
It is almost 100 years since Otto Röhm introduced the first industrial application of an enzymatic product. This was the bating process of animal hides within leather production, the enzymes being derived from pancreatic glands. This can be seen
World Leather - Oct 2004
Downloadable PDF Wasserglass in leather production
The main objective of this project—funded by the CRAFT programme of the EC(2)—was to develop findings from a previous investigation on the application of Wasserglass. In the study, procedures for pelt treatment with Wasserglass(3)
World Leather - Aug/Sep 2004
Downloadable PDF Wasserglass in leather production
The main objective of this project—funded by the CRAFT programme of the EC(2)—was to develop findings from a previous investigation on the application of Wasserglass. In the study, procedures for pelt treatment with Wasserglass(3)
World Leather - Aug/Sep 2004
Downloadable PDF Observations: Temperature related relaxation within liming and other wet processes
It is well known that by liming at higher temperatures, say, 29°C instead of 25°C, that hides and skins are softer, show less draw and growth marks, and appear less swollen. In addition, after fleshing there is a greater loss of fine wrinkles in
World Leather - Aug/Sep 2004
Downloadable PDF Reducing salinity in the pickle-tanning process. Part 2
Salinity is a cause for concern in tannery waste waters as it is unaffected by effluent treatment and more that 25% of salinity can be generated from the pickle-chrome tanning process.
World Leather - May 2004
Downloadable PDF Reducing salinity in the pickle-tanning process. Part 1 of 2
The following paper describes a series of structured investigations with the objective of eliminating common salt from the pickle-chrome tanning process.
World Leather - April 2004
Downloadable PDF Aqueous degreasing and the custom designed surfactant
The degreasing of hides and skins can be considered state of the art. Excluding the use of solvents, the most effective water-based products are nonylphenol ethoxylates (NPEs).
World Leather - Nov 2003
Downloadable PDF Iron tannage: an alternative chrome-free tanning system
Due to ecotoxicological reasons and the growing need for recyclability, today’s classical tanning systems are under close review.
World Leather - Aug/Sep 2003
Downloadable PDF Addressing Scope 3 emissions
Stahl’s climate change mitigation ambitions include the reduction of its Scope 3 (upstream) greenhouse gas emissions by 25% over the next 10 years as well as supporting customers in achieving their own climate goals.
World Leather - Feb/Mar