Explore the vast range of titles available.

This study explores vegan leather, an eco-friendly substitute for conventional animal-derived leather. Using materials like polyurethane, pineapple leaves, cork, and recycled plastics, vegan leather aims to transform the fashion industry and consumer products while addressing environmental concerns. Despite its advantages, challenges related to availability and durability persist. The booming market for vegan leather is expected to reach billions of dollars, reflecting a broader societal shift towards sustainable and cruelty-free alternatives. The review traces the historical development of vegan leather from its origins in Germany to modern innovations like Mylo and Piñatex. By comparing these materials to conventional leather, the study assesses their potential to replace animal-derived leather. Looking at different types of sustainable leather, like synthetic, plant-based, mycelium, and collagen-based leather, shows how they connect with being environmentally friendly and made from natural materials. The ultimate aim is to contribute to ongoing discussions about transitioning to a circular economy, where durable bio-based and biodegradable materials offer a promising future for sustainable leather alternatives.

Leather is one of the most popular products across globe and holds a significant place in the economy, while the pollution, associated to traditional leather industry, is far away on the “green chemistry” principles. In this sense, polyurethanes, which exhibit tunable chemical structures by selecting suitable precursors, can fit specific requirements, and the developments of green strategies make them important candidates for leather industry. This mini review briefly outlines the recent development of conventional (petrol-based) and sustainable polyurethanes in the leather industry, including their design and properties, in applications such as synthetic leather and surface-finishing (coatings/binders). Finally, outlooks of the future tendency, including more environmental-friendly strategies, bio-sourced/recycled materials and development of high-value multifunctional leather materials, are also here proposed.

Most natural substances can be utilized as raw materials to manufacture leather-like bio-based materials, including animals, plants, and microorganisms.The development of leather-like bio-based materials using industrial waste has promoted the industry’s transition from a linear economy to a circular economy.Vegan fashion is on the rise, and the emergence of leather-like bio-based materials as a new type of leather substitute material is in line with the expectations of environmentally conscious consumers who care about environmental protection and animal rights.A huge variety of leather-like biological products has shown advantages and unique characteristics over natural leather in certain aspects. The development of leather-like bio-material materials has not stopped and should continue to grow. Leather is important to the global manufacturing industry, contributing to both the economy and society. However, because of ecological and ethical considerations, alternative bio-based materials to natural leather are now being investigated. Advancements in biotechnology and bio-based materials, combined with flourishing biomanufacturing, have driven product development. In recent years, animal-free, biotechnology-based leather-like material has seen significant growth. Recent progress in leather-like bio-based materials development has been achieved using proteins, mycelium, cellulose, and other sustainable natural materials. This review provides a comprehensive overview of these bio-based materials, addressing their challenges, practical implications, and potential to play a growing role in the emerging field of animal-free alternative. The development of ‘future leather’ has significant economic and environmental potential. Leather is important to the global manufacturing industry, contributing to both the economy and society. However, because of ecological and ethical considerations, alternative bio-based materials to natural leather are now being investigated. Advancements in biotechnology and bio-based materials, combined with flourishing biomanufacturing, have driven product development. In recent years, animal-free, biotechnology-based leather-like material has seen significant growth. Recent progress in leather-like bio-based materials development has been achieved using proteins, mycelium, cellulose, and other sustainable natural materials. This review provides a comprehensive overview of these bio-based materials, addressing their challenges, practical implications, and potential to play a growing role in the emerging field of animal-free alternative. The development of ‘future leather’ has significant economic and environmental potential.

Background A wide variety of bacterial species produces protease enzyme, and the application of the same enzyme has been manipulated precisely and used in various biotechnological areas including industrial and environmental sectors. The main aim of this research study was to isolate, screen, and identify alkaline protease-producing bacteria that were sampled from leather industry effluent present in the outer skirts of Addis Ababa, Ethiopia. Purpose To isolate and characterize the alkaline protease-producing bacteria from leather industrial effluents. Methods Samples are collected from Modji leather industrial effluents and stored in the microbiology lab. After isolated bacteria from effluent using serial dilution and followed by isolated protease-producing bacteria using skim milk agar media. After studying primary and secondary screening using zonal inhibition methods to select potential protease-producing bacteria using skim milk agar media. Finally, to identify the potential bacteria using biochemical methods, bacterial biomass, protease activity, and gene sequencing (16S rRNA) method to finalize the best alkaline protease producing bacteria identified. Results First twenty-eight different bacterial colonies were isolated initially from the leather industry effluent sample situated at the Modjo town of Ethiopia. The isolated bacteria were screened using the primary and secondary screening method with skim milk agar medium. At the primary level, we selected three isolates namely ML5(14 mm), ML12(18 mm), and MS12 (15 mm), showing the highest zone of proteolysis as a result of casein degradation on the agar plates were selected and subjected to primary screening. Further secondary screening confirmed that the zone of inhibition methods ML5 (14.00±0.75 mm), ML12 (19.50±0.66 mm), and MS12 (15.00±1.32 mm) has efficient proteolytic activity and can be considered as effective protease producer. The three isolates were then subjected to morphological and biochemical tests to identify probably bacterial species, and all the three bacterial isolates were found out to be of Bacillus species. The shake flask method was carried out to identify the most potent one having greater biomass production capabilities and protease activity. ML12 isolated from leather effluent waste showed the highest protease activity (19 U/ml), high biomass production, and the same was subjected to molecular identification using 16s sequencing and a phylogenetic tree was constructed to identify the closest neighbor. The isolate ML12 (Bacillus cereus strain -MN629232.1) is 97.87% homologous to Bacillus cereus strain (KY995152.1) and 97.86% homologous to Bacillus cereus strain (MK968813.1). Conclusions This study has exposed that from twenty-eight different bacterial samples isolated from leather industry effluent; further primary and secondary screening methods were selected three potential alkaline protease strains. Finally, based on its biochemical identification, biomass, and protease activity, ML12 (Bacillus cereus strains) is the best strain identified. The alkaline protease has the significant feature of housing potent bacterial species for producing protease of commercial value.

Increasing consumer quality awareness and increase in consumer wealth drives the market demand for high quality leather and leather products. Reliable and effective detection and classification of leather surface defects is of profound significance to tanneries and industries where leather is a major raw material for leather accessories and leather parts manufacturers. This paper presents a methodical and a detailed review of the leather surface defects detection methods starting from leather image acquisition, leather image processing, feature extraction and classification for defect detection. Firstly, we introduce the fundamentals of leather image acquisition and various related image processing methods, feature extraction and classification for the defect inspection. Next, the existing datasets and summary of the recent methodologies used in this field are discussed. Finally, the challenges and suggested improvements to further the development of the application of advanced Machine Learning and Deep Learning in this field are discussed. Deep learning algorithms are shown to have a great potential for leather surface defect detection and can help prepare a robust system that would greatly guarantee quality leather and provide monetary wealth from such leather products. Finally, research guidelines are presented to fellow researchers regarding data augmentation, leather defect detection models which need to be investigated in the future to make progress in this crucial area of research.

This investigation was focused on evaluating the utilization of Leather-waste, i.e., “Leather Shavings”, to develop “Poly(ethylene-vinyl-acetate)” (EVA) based “polymer matrix composites”. Composites with the highest ratio of 1:1 were developed using a rolling-mill, which was then subjected to hot-press molding for value-added applications, notably in the “floor-covering”, “structural”, “footwear”, and “transportation domain”. The specimens were examined for evaluating the “physico-mechanical characteristics” such as, “Compressive and Tensile, strength, Abrasion-resistance, Density, tear-resistance, hardness, adhesion-strength, compression, and resilience, damping, and water absorption” as per standard advanced testing techniques. Raising the leather-fiber fraction in the composites culminated in considerable enhancement in “physico-mechanical characteristics” including “modulus”, and a decline in “tensile-strain” at “fracture-breakage”. The thermo-analytic methods, viz. TGA and DSC studies have evidenced that substantial enhancement of thermo-stability (up to 211.1–213.81 °C) has been observed in the newly developed PMCs. Additionally, the DSC study showed that solid leather fibers lose water at an endothermic transition temperature of around 100 °C, are thermo-stable at around 211 degrees centigrade, and begin to degrade at 332.56-degree centigrade for neat recycled EVA samples and begin to degrade collagen at 318.47-degree centigrade for “leather shavings/recycled EVA polymer composite samples”, respectively. Additionally, the “glass transition temperature” (Tg) of the manufactured composites was determined to be between −16 and 30 °C. Furthermore, SEM and EDAX analysis have been used to investigate the morphological characteristics of the developed composites. Micrograph outcomes have confirmed the excellent “uniformity, compatibility, stability and better-bonding” of leather-fibers within the base matrix. Additionally, the “Attenuated-total-reflection” (ATR-FTIR) was carried out to test the “physicochemical chemical-bonding”, “molecular-structure”, and “functional-groups” of the “base matrix”, and its “composites” further affirm the “recycled EVA matrix” contained additives remain within the polymeric-matrix. An “X-ray diffraction study” was also conducted to identify the “chemical-constituents” or “phases” involved throughout the “crystal-structures” of the base matrix and PMCs. Additionally, AFM analysis has also been utilized to explore the “interfacial adhesion properties” of mechanically tested specimens of fabricated polymeric composite surfaces, their “surface topography mapping”, and “phase-imaging analysis” of polymer composites that have leather-shavings fibers.

Genuine leather is produced from animal skin by chemical tanning using chemical or vegetable agents, while synthetic leather is a combination of fabric and polymer. The replacement of natural leather by synthetic leather is becoming more difficult to identify. In this work, Laser Induced Breakdown Spectroscopy (LIBS) is evaluated to separate between very similar materials: leather, synthetic leather, and polymers. LIBS is now widely employed to provide a specific fingerprint from the different materials. Animal leathers processed with vegetable, chromium, or titanium tanning were analyzed together with polymers and synthetic leather from different origins. The spectra exhibited typical signatures from the tanning agents (Cr, Ti, Al) and the dyes and pigments, but also from polymer characteristic bands. The principal factor analysis allowed to discriminate between four main groups of samples representing the tanning processes and the polymer or synthetic leather character.

The leather manufacturing sector is actively pursuing organic alternatives to replace the utilization of inorganic tanning chemicals such as chromium, zirconium, and aluminum due to concerns over their environmental impact. Although glutaraldehyde has been considered a feasible alternative, it still falls short in providing the leather with greater tensile properties and is also considered to be toxic. In this study, we report the synthesis of a sulfonated gallic acid-based epoxide (GSE) and evaluate its performance as a metal-free tanning compound. The synthesized compound was subjected to comprehensive characterization using FTIR (functional group), ESI-MS (molecular weight), and NMR (chemical environment) spectroscopy. Furthermore, the leather treated with GSE demonstrated organoleptic and physical properties that were comparable to those achieved with glutaraldehyde tanning systems. SEM analysis of the GSE-tanned leather exhibited a homogeneous distribution pattern, confirming the stability of the collagen. In addition, the hydrothermal stability temperature of leather crosslinked with epoxide was found to be 83 ± 2 °C. The wastewater generated from the GSE tanning process exhibited a BOD to COD ratio of 0.35 ± 0.04, indicating its high treatability. The results showed that the GSE tanning system provided better tanning efficiency and improved crosslinking and thermal stability without the use of metal salts. Furthermore, the use of GSE as a tanning agent offers several advantages, such as easy availability, biodegradability, and low toxicity, making it a sustainable and environment-friendly option for the leather industry. Graphical Abstract

The market for biogenic and synthetic alternatives to leather is increasing aiming to replace animal-based materials with vegan alternatives. In parallel, bio-based raw materials should be used instead of fossil-based synthetic raw materials. In this study, a shoe upper leather and an artificial leather, and nine alternative materials (Desserto®, Kombucha, Pinatex®, Noani®, Appleskin®, Vegea®, SnapPap®, Teak Leaf®, and Muskin®) were investigated. We aimed to compare the structure and technical performance of the materials, which allows an estimation of possible application areas. Structure and composition were characterized by microscopy and FTIR spectroscopy, the surface properties, mechanical performance, water vapor permeability, and water absorption by standardized physical tests. None of the leather alternatives showed the universal performance of leather. Nevertheless, some materials achieved high values in selected properties. It is speculated that the grown multilayer structure of leather with a very tight surface and a gradient of the structural density over the cross-section causes this universal performance. To date, this structure could neither be achieved with synthetic nor with bio-based materials.

Leather manufacturing is the process of transforming animal skin into high value-added commodity. As a crucial step in the leather producing process, conventional chrome tanning could lead to discharge of chromium contaminant due to the low efficiency of chromium uptake. In this paper, a series of polyethylene glycol triazine derivatives’ tanning agent (PT) with different molecule weight was synthesized with one-step method and applied in the main tanning of hide. The chemical structure of the PT was detected by FT-IR and 1 H-NMR. The application experimental results indicated that after 16% of PT tanning at pH of 6, the wet-white was endowed with shrinkage temperature over 80°C and thickening rate over 108%. The experimental results indicated that the PT tanning leather not only have a better physical and mechanical properties than commercial triazine derivatives tanning agent, but also the leather is endowed with the effects of outstanding thermal properties. Considering that the pickling process became unnecessary, a large number of neutral salts could be avoided, the chromium load in spent liquor decreased from 1288 mg/L to 0, and the total dissolved chlorine in spent liquor decreased from 15,360 to 9581 mg/L; no toxic and harmful substances such as chromium and aldehyde are introduced into the tanning process. Compared with the leather tanned with commercial triazine derivatives’ tanning agent, the leather tanned with PT showed a similar overall tanning properties and better environmental friendliness, which makes PT matches the integral requirements of the modern sustainable leather industry.