1,720,983 research outputs found
Study on the use of fleshings-derived collagen in post tanning operations
No full textThe leather industry generates waste either in solid or liquid form. Fleshing, which is integral part of a hide, is removed during leather processing as it is an unwanted material in the final product. For every ton of leather processed, about 100-150 kg of fleshing is generated. An alternative to disposal of these wastes is to reuse them. In this study, an experimental activity research for assessing the feasibility of the reuse of the collagen hydrolizate in the retanning/dyeing/fatliquoring phase was performed. The hydrolyzed collagen, in liquid form, is obtained by alkaline hydrolysis of fleshings. The hydrolizate has been used both in a vegetablechrome retannage/dyeing/fatliquoring and in a vegetable retannage/dyeing/fatliquoring to obtain bovine upper leather. Both in a vegetable-chrome retannage and in a vegetable retannage, the final leathers showed similar properties in terms of physical and technical properties to conventionally processed hides. The results obtained indicate that the use of the collagen hydrolizate in the retanning/dyeing/fatliquoring phase as an interesting route for recovering the fleshings
Depoxo process: technical and environmental study of hide oxidative unhairing
Full text linkAs an alternative to the traditional process based on the use of sulfides, an unhairing process in drum by hydrogen peroxide, named DEPOXO, was developed for the production of high-quality bovine upper leather. A preliminary investigation at laboratory scale has allowed to set out the optimal process conditions, in terms of H2O2 dosage (9 %) and pH (12.5), in order to achieve an effective unhairing and a compatible swelling of hides. The following pilot-scaled runs have assessed the industrial feasibility of the process that allows the production of a versatile base for different final applications of the leather (either chrome or vegetable tanned), and appear practical to implement. The crust leather obtained by the oxidative unhairing process showed good physical-mechanical and technical properties comparable with those obtained by the traditional one, and the leather was technically assessed as satisfactory and suitable according to the market request. The actual reduction of the environmental impact of the novel process, in relation with the traditional one, was evaluated performing a Life Cycle Assesment (LCA) using SimaPro 7.3, one of the most used software for LCA analysis. The results of the life cycle impact assessment underline that damages on main impact categories are greatly reduced through the adoption or the oxidative unhairing. Therefore, the DEPOXO process appears a feasible process, either from the environmental or from the technical point of view, to produce high quality bovine upper leather
Properties of thermoplastic blends with polypropylene and collagen hydrolizate
No full textPolypropylene-based composites are prepared using hydrolyzed collagen (HC) from wastes of the leather industry. Blends of polypropylene and HC were studied as a function of the blend composition ratio with the aim of developing a formulation with optimal physical-chemical and mechanical properties. The prepared mixtures were characterized by thermal analyses and mechanical test. Blends with content up to of 20-30% of collagen hydrolizate are susceptible to be melt processed to provide transparent, cohesive and flexible films. In front of positive results the reutilization of collagen hydrolizate derived from the tannery industry appears feasible for production of thermoplastic items for applications in packaging and agricultural segments
Use of tannery sludge ash as filler in waterproofing membranes
No full textTannery effluent treatment plant sludge is a by-product of leather-making industry in which chrome compounds are the most common used materials. The aim of this work was to investigate the effects and feasibility in the use of tannery sludge ash as a partial or totally replacement of usual mineral filler such as CaCO3 in manufacture of waterproofing membranes. The effects of sludge ash on the morphology and mechanical properties of membranes were investigated. Leaching tests were carried out in order to guarantee that the fulfillment of "filler function" was done in respect with environmental criteria. The results in terms of performances and leaching tests indicate that tannery sludge ash could be used as total replacement of CaCO3 for waterproofing membranes. This work has to be intended as the first step of a study whose final goal is to find an effective, industrially applicable, way to improve recycling capabilities of tannery effluent treatment plant sludge in systems like roofing and waterproofing membranes thus solving an economical and environmental problem
Novel thermoplastic materials from wastes of the leather industry
No full textHydrolyzed collagen from leather industry is a natural polymer easily available at low cost and its use is not in competition with food industries or other main applications because it is a waste material and a by-product of the tanning process. In this work, polyethylene-collagen hydrolizate blends, at ratios of 100/0, 90/10 and 80/20, were processed using a blow film line equipped with a single screw extruder. Film blowing is a shaping technique used extensively to produce most plastics films and bags for packaging applications. The effect of processing parameters on the physical properties of blown films was investigated. The extruded films were characterized through mechanical testing, scanning electron microscopy, and thermal analysis. The manufactured films showed satisfactory mechanical and thermal properties, thus polyethylenecollagen hydrolizate blends appears as promising candidate for the production of innovative material suitable for production of thermoplastic items for applications in packaging and agricultural segments
Sustainability in process innovation: development of a green tanning process supported by LCA methodology
No full textAs a response to the growing concerns about a variety of environmental issues expressed by public opinion and political bodies, the leather industry needs to support its market by environmental criteria as a guarantee of quality. For this reason, assessment tools as Life Cycle Assessment (LCA) methodology, which allow a more thorough knowledge of the products to the enterprises and can help to guide the environmental policies, are recommended (e.g. EC Directive on Ecologic Labels).
The LCA methodology, described in details by the ISO 14000 series, allows the assessment of the environmental impacts due to products, processes, or services, by the identification of the inputs (e.g. energy and material consumption) and outputs (e.g. waste and pollutant production) streams exchanged by the process with the environment (i.e. from raw materials procurement to waste streams disposal). The application of LCA as tool for integration of sustainability aspects in process design and development is gaining wider acceptance and methodological development.
In this study, the life cycle modeling was used to support the development of a novel tanning process based on the use of a new class of tanning agent produced from renewable resources (e.g. glucose). The experimental activity performed to investigate the technical feasibility of the innovative tanning cycle was supported by the modelling of the process using the LCA methodology in order to assess the environmental performance of the leather production cycle. Therefore, an LCA analysis was performed in order to compare the glucose-tannage process with the traditional one from an environmental point of view
Utilization of Tannery Wastewaters Sludge Ash in Waterproofing Membrane: A Technical and Environmental Feasibility Study
No full textSludge from tannery effluent treatment processes is a by-product of leather-making
industry, in which chrome compounds are the most common used materials. The objective of this
work was to investigate the effects and feasibility in the use of tannery sludge ash as a partial or
total replacement of usual mineral filler such as in manufacture of waterproofing membranes. The
effects of sludge ash on the morphology and mechanical properties of membranes were
investigated. Leaching tests were carried out in order to guarantee that the fulfilment of “filler
function” was done in respect with environmental criteria. Besides, a Life Cycle Assessment (LCA)
analysis was performed in order to assess the environmental performance of the waterproofing
membrane filled by tannery sludge ash in comparison with the conventionally filled membrane. The
performances of the membranes and the results of environmental assessment indicate that tannery
sludge ash may be used as total replacement of CaCO3 for waterproofing membranes
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