Conventional Chromium Research Articles

Keratin hydrolysate as a chrome exhaust aid and keratin filler in leather processing: A cleaner technology approach for tannery solid waste management and leather manufacturing

Hair burning unhairing and dampening of tannery wastes during the hair-saving unhairing process are becoming significant problems in the tanning industry. Therefore, this research article focuses on the extraction of keratin hydrolysate (KH) and its application as a chrome exhaust aid and keratin filler in leather manufacturing process. The structure, morphology and functional groups of the extract were examined using X-Ray Diffractometer (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometer (FTIR), respectively. To study and contrast the degree of improvement in chromium uptake, the KH solution was applied both before tanning on the pickled pelt and after tanning during basification. The thermal stability, physical strength characteristics and organoleptic properties of the leathers obtained were characterized. Furthermore, the environmental impact of the tanning system was assessed through a comparative analysis of the spent liquors. Finally, experimental retanning process was conducted to replace the commercial protein filler (Celatan F: 50, 75, and 100 %) with KH solution, with concurrent processing of control leather using conventional chrome tanning agent at 6 % dosage of chromium. The FTIR analysis of the extract confirmed the presence of alkyl side chains of amino acids as well as carboxylic, amide, carboxyl group and aldehyde functional groups at 1400-1700 cm−1,3,303.46 cm−1,3270 cm−1 and 2752 cm−1, respectively. XRD spectrum showed two diffraction peaks at 2 theta values of 9.36° and 21.16°, respectively. Leathers with improved mechanical strength, organoleptic properties and thermal stability were obtained with 100 % substitution of Celatan F at pH 6 and 10 % chromium dosage. It was also discovered that the shrinkage temperature of the experimental leather was enhanced to more than 105 °C. Environmental impact evaluation on the spent liquor showed that the complete replacement of Celatan F with KH solution brought about a notable decrease in COD and TDS in the spent liquor. The extraction and application of tannery hair waste-based keratin hydrolysate as an efficient, environmentally friendly chrome exhaust aid and keratin filler has been attempted and established in this research article.

Energy-saving and low-carbon leather production: AI-assisted chrome tanning process optimization

Reducing CO2 emissions is a global effort to improve industrial cost efficiency, enhance product compatibility, and fight climate change. For leather-making industry, the optimization of tanning process is crucial to fulfill the goal of low-carbon manufacturing. Artificial intelligence (AI) is an emerging technology for its ability to reduce errors, increase efficiency, and help realizing precise optimization of manufacturing processes. Herein, an AI-assisted method was first proposed to optimize chrome tanning process for energy-saving and carbon reduction. By comparing the performance of four machine learning (ML) algorithms, i.e., multiple linear regression (MLR), polynomial regression (PR), support vector regression (SVR), and backpropagation-artificial neural network (BP-ANN), it was found that machine learning models are superior in identifying the optimization of process parameters (pH and time) which lead to maintain key product quality indexes in the penetration procedure and binding procedure. Out of the four ML models, the BP-ANN algorithm and SVR algorithm are proven to have good predictive ability. Thus, we systematically optimized the chrome tanning process for energy saving, with key product quality as the constraints. The optimal process parameters, namely pickling pH of 2.86, penetration time of 90 min, pH after basifying of 4.08, and binding time of 90 min, were generated by solving the optimization models of the chrome tanning process via the genetic algorithm (GA) with powerful global optimization capability. Finally, it was validated that the optimized process was highly reliable by evaluating the wet blue product performances, such as the evenness of chrome distribution, thermal stability, surface reactivity, morphology, as well as physical and mechanical properties. Notably, compared to conventional chrome tanning, the optimized process will save 8353.33 kgce of energy and reduce 87295.6 kgCO2 of CO2 emission in an average tannery with an annual production capacity of 300,000 standard sheets of upper cowhide leather. This approach can precisely optimize conventional leather-making process, providing a fesible way to achieve energy-saving and low-carbon leather production.

Tuning a green carboxymethyl cellulose-based pre-tanning agent via peroxide oxidation for high chrome exhaustion in leather industry

The low chrome uptake by collagen in the conventional tanning process leads to the pollution of the wastewater. Due to environmental concerns, leather scientists are already searching for innovative ways to produce pre-tanning agents as a high exhaustion chrome tanning auxiliary. Herein, a novel kind of pre-tanning agent is engineered by converting carboxymethyl cellulose (CMC) to oxidized carboxymethyl cellulose (OCMC) via the hydrogen peroxide process. FT-IR and carboxyl content analysis demonstrated the increase in carboxyl content after oxidation. After that, the obtained OCMC was utilized as a pre-tanning agent, resulting in a high exhaustion of chrome (92.76 %) which is 27.76 % more than conventional chrome tanning (65 %), and the amount of chrome in wastewater reduced to 7.24 %. The hydrothermal stability of wet-blue increased by increasing the uptake of chrome (Ts = 118 °C). The obtained crust leather represented excellent mechanical properties (Tensile strength: 305.68 kg/cm2; tear strength: 50 kg/cm) and desirable organoleptic properties. The environmental analysis signifies a significant step towards a cleaner and sustainable tanning process (COD = 1600, BOD5 = 560 mg/L) compared to the conventional chrome tanning process. Consequently, the obtained results offer a green pre-tanning agent to meet the requirements of the sustainable development of the leather industry.

Impact of Milled Peek versus Conventional Chrome Cobalt Framework on Retention of Definitive Obturators for Unilateral Total Maxillectomy Patients

Impact of Milled Peek versus Conventional Chrome Cobalt Framework on Retention of Definitive Obturators for Unilateral Total Maxillectomy Patients

The development of chrome free chestnut and Tetrakis Hydroxymethyl Phosphonium Sulfate based Eco-benign combination tanning system

The replacement of the conventional chromium tanning system with an eco-benign tanning systems has received great attention owing to stringent environmental regulations. In this specific study, a chrome-free combination tanning system based on chestnut and tetrakis (hydroxymethyl) phosphonium sulfate (THPS) was developed and presented as an effective alternative cleaner tanning technology. Processing of the tanning trials were carried out varying the percentages of chestnut as a tannage, followed by THPS as a re-tannage for process optimization. The leathers obtained were characterized for their thermal stability, grain surface properties using a scanning electron microscope, physical strength characteristics, comfort, and organoleptic properties. Finally, the environmental impact of the tanning systems was assessed through the comparative analysis of their spent liquors. The chestnut-THPS combination system tanned leathers using 20 % chestnut followed by 2 % THPS resulted in maximum shrinkage temperature of 95OC. The hydrothermal stability of the leathers tanned using this combination tanning system were found to be better than those tanned using chestnut and THPS tanning systems alone, respectively. The strength and comfort properties of the leathers produced using the developed combination tanning system were found to be on par with or better than those of conventionally tanned leathers, and the scanning electron microscopic study depicted that the grain surface of the leathers produced were observed to be free of surface deposition. The environmental impact assessment showed that the combination tanning system used resulted in a significant reduction in TS, TDS, TSS, and BOD in the wastewater. This research article has attempted and established the use of chestnut-THPS-based combination tanning systems as an effective, eco-friendly alternative tanning process technology.

Effect of nano yttria stabilized zirconia on corrosion behaviour of chromium oxide coatings on boiler steel

In this research work, 5 wt.% nano yttria-stabilized zirconia (YSZ) reinforced chromium oxide-based nanocomposite coatings were prepared and successfully deposited on ASME-SA213-T-22 (T22) boiler tube steel substrates using high-velocity oxyfuel (HVOF) thermal spraying method. The corrosion behaviour of composite coating has been compared with that of conventional chromium oxide coating. All the coatings were analysed by scanning electron microscope, energy-dispersive X-ray spectroscopy and X-ray diffraction. It was found that the addition of 5 wt.% YSZ in the Cr2O3 matrix results in the reduction of the porosity of the coating and an increase in hardness. During corrosion investigations, it was found that YSZ-reinforced Cr2O3 nanocomposite coating on T22 provides better corrosion resistance than conventional Cr2O3 coating in the molten salt environment at 900 °C. The inclusion of YSZ has reduced porosity by filling in the gaps in the chromium oxide coating, causing particle interlocking, and preventing the entry of corroding species.

Life cycle assessment insights into nanosilicates-based chrome-free tanning processing towards eco-friendly leather manufacture

Chrome tanning system has been faced with great challenges from potential environmental and human health risks and environmental pressures in the leather industry. The development of chrome-free tanning system towards eco-friendly leather manufacture is the main strategy to solve them from the source. However, appropriate assessments of the physical and environmental properties of a new tanning process remain challenging. In this work, we compared the physical performances and environmental impacts of two nanosilicates-based chrome-free combination tanning systems with conventional chrome tanning system in practical fur leather processing. The objective of this study was to obtain comprehensive insights into the nanosilicates-based chrome-free combination tanning systems from both technical and environmental perspectives. All fur leathers possessed similar and integrated fleece structures, ensuring high glossy and flexibility of final fur leather articles. Tara tannin-Zeolite (TA-ZE) combination tanning system was chosen as the most promising one for manufacturing garment leather articles. The resultant leathers were endowed with favorable physical properties (e.g., tear strength of 15.9 N, elongation at break of 42.3%, shrinkage temperature of 98.6 °C) and no restricted Cr(VI) and free formaldehyde. Life cycle assessment (LCA) results revealed that the TA-ZE combination tanning system exhibited better environmental impacts than other options. The main novelties included the contribution to avoiding the use of high-risk tanning chemicals by presenting a better technical and environmental alternative in the leather processing and the application of LCA to environmentally evaluate the leather processing. We envision these findings can offer comprehensive insights into emergent chrome-free combination tanning systems for designing and rationalizing feasible fur leather processing towards eco-friendly leather manufacture.

Recovery and Reuse of Chromium from Tannery Waste Chrome-liquor using Solar Evaporation Process

Recovering and reusing chrome from chrome effluent is critical for improving the mass balance of the tanning process and implementing the zero liquid discharge concept in the tanning industry. Conventional chrome recovery methods require a large amount of chemicals or energy to recycle the chromium. Chrome recovery by solar evaporation has not been implemented yet in the tanning industry. It is mainly practised in seawater salt extraction. In this study, we demonstrate the construction of highly efficient solar evaporators, using photothermal materials. Our focus is on efficient solar-to-vapour conversion and chrome recovery. The average evaporation rate was calculated and found 38.69 mL/hour, which remained almost steady within 2.5 months of data collection. The highest temperature observed during the process was 108 °C and 62°C in the focal region and condenser respectively. After collecting the solid chromium, basicity was measured at 85.02%, and treated with sulphuric acid to achieve 33% basicity. Recovered chrome and fresh chrome at 0:8, 5:3, and 8:0 were used for chrome tanning and tested for various chemical and physical parameters of tanned leather. The shrinkage temperature of the produced leather was found to be more than 100 °C. Physical characteristics such as tensile strength and percentage of elongation test, stitch tear strength, ball bursting strength and flexing endurance showed better results than conventional methods. This new kind of research offers a promising solution that can reduce the environmental impact of the tanning industry while also providing a sustainable source of chromium for a low-cost strategy and high-performance evaporation approach.

Biomass-based Tanning Agent for Sustainable Leather Manufacture via Cyanuric Chloride Modified Chitooligosaccharide

Developing alternative tanning agents to avoid the potential environmental and human health risks from the conventional chrome tanning is essential for the leather industry. In this work, we prepared an eco-friendly biomass-based tanning agent dichlorotriazinyl chitooligosaccharide (DTCS) by modifying chitooligosaccharide (COS) with cyanuric chloride (CC) for chrome-free leather manufacture. The synthesis of such biomass-based tanning agent was systematically optimized to obtain the target product with high grafting degree of 67% and weight-average molecular weight (Mw) of 1465 g/mol. The non-pickling tanning procedure using DTCS was investigated, and the interactions between DTCS and collagen fibers were studied. Our results showed that the hydrothermal stability of the tanned leather was significantly increased, i.e., the shrinkage temperature (Ts) exceeding 82.0°C, and the mechanical properties were improved. Moreover, the organoleptic properties of leather (e.g., fullness, softness and grain tightness) exhibited obvious improvement. This research not only offers a reliable approach for cleaner leather manufacturing while addressing the underlying ecological pressure, but also highlights the emerging use of biomass materials in the leather industry.

Amalgamated silica-glutaraldehyde based cost effective leather tanning agent and its sustainable benefits: A metal free collagen stabilisation

Presently, there is a need for development of cleaner and sustainable tanning system by introducing biocompatibility and degradability to the leather without affecting its physical properties. Particularly, tanners seek chrome-free tanning systems due to their cleaner image, market demand, and good physical properties. Amongst tanning agents, silica and its combination have been identified as a greener tanning system. In the present study, a combination tanning system based on surface modified silica and aldehyde has been developed. The main invention lies in identifying a new tanning system based on silica with an amine terminal followed by dialdehyde post treatment with an appropriate post-tanning process. Initially, the silica will stabilize the collagen fibres through multiple hydrogen bonding and electrostatic interactions. Later, adding aldehyde enhances the bonding between silica and collagen through multiple intermolecular crosslinking. This was further validated by the molecular interaction studies of collagen with a silica-glutaraldehyde combination system. This developed chrome-free tanning process produces leathers exhibiting reasonable thermal stability of around 90 °C with reduced chemical oxygen demand (COD) load and no chromium in the wastewater. Due to the synergistic effect of silica and aldehyde, even the tanned leather exhibited improved antimicrobial activity against gram-positive Bacillus subtilis and gram-negative Escherichia coli. One of the main benefits of this new tanning system is the lower environmental impact with an E-factor of 0.23. Sustainability indicators suggest that the tanning by silica combination found to be environmentally friendly and cost effective method as compared to conventional chrome tanning process.

The study on performances of environment-friendly colorless chemical conversion coatings on aluminum alloy

With the increasingly high requirements on the appearance of electronic equipment and environmental protection, conventional chromate chemical conversion coatings on aluminum alloys gradually showed some shortcomings, such as the color difference in appearance and harm to human health and the environment in the process. In this paper, three kinds of environment-friendly colorless chemical conversion coatings (LANTH-613, ALTRCHR-250, YMT-631) were prepared by using 5056 and 6061 aluminum alloy samples and visually observing the appearance of the coatings. Then, the performances of the coatings, such as the morphology, corrosion resistance, electrical contact resistance, and paint adhesion, were characterized by scanning electron microscope, salt spray test, electrical contact resistance test, and cross-cut test, respectively. As a result, we proposed YMT-631 colorless chemical conversion coating could be used alone as a long-term protective coating for aluminum alloy parts that require the natural appearance of aluminum in electronic equipment, by which corrosion resistance and adaptability in the harsh environment could be significantly improved.

Microstructure control of Ti-based conversion coatings for optimizing organic coating properties in A6063 and A3003 alloys

Ti-/Zr-based conversion coatings are environmentally friendly alternatives to conventional chromate conversion coatings. A prerequisite for their widespread use on aluminum alloys is an efficient treatment process applicable to multiple alloys. In this study, Ti-based conversion coatings with an ideal microstructure were successfully formed on both A6063 and A3003 under the same conversion bath conditions. These coatings exhibited satisfactory impact adhesion with organic coatings and salt spray corrosion resistance for practical applications. In-depth analyses of the deposition process of Ti-based conversion coatings by scanning and transmission electron microscopy showed that Ti-oxide nanoparticles were initially deposited on the matrix, which grew into a continuous layer on A6063, whereas a continuous Ti-oxide layer was formed on A3003 from the initial immersion stage. Lowering the pH of the conversion bath prevented the continuous growth of the Ti-oxide layer on A6063, thereby reducing the adhesion and corrosion resistance. Increasing the bath concentration accelerated the growth rate of Ti oxides in A3003 and A6063, and the formation of Ti oxides with excessive thickness reduced the adhesion. By optimizing the concentration and pH, a continuous Ti-oxide layer of 20–40 nm thickness was formed with a reasonable growth rate on both A6063 and A3003, resulting in satisfactory impact adhesion and salt spray corrosion resistance.

Tannery: Environmental impacts and sustainable technologies

The tannery is an old industrial sector well-developed, plays an important role in the global economy, and has been heavily industrialized over the years in all countries. In developed countries, the legislation forces the tannery sector to develop clean and sustainable production. Due to the strict legislation policies, there was a continuous change in the distribution of the processing sites. There are two main reasons for this shift of the distribution, namely: 1) lower labour costs in some countries than in others; 2) fewer environmental restrictions in some countries than in others.The current tanning process is still mainly based on the traditional one, making use of chromium salts and being able to give leather of very high quality, despite its severe environmental drawbacks. Since its industrialization, the tannery has shown its heavy environmental impacts, caused by the operations and the processes done in the productive/supply chain, from the raw hides and skins to the final leather. Especially, this sector consumes a huge amount of water, which generates wastewater with high concentrations of pollutants (mainly, chromium(III), sodium sulfide, ammonium chloride, biocides, aldehydes, dyes, etc.). Emissions to the air and solid waste production are worth of consideration, too. At last, the health effects on the workers can give problems in the short as well as long term.Looking at the current distribution of the processing sites, most are in developing countries, where the legislation is still weak.Little amounts of leather derive from the green tannery, where the use of chromium is limited or completely avoided. The reason is the lower quality of the leather produced by the so-called “green technologies”.This paper analyzes the impacts deriving from the tannery industry due to the conventional chromium process. The reduced-chrome processes and green technologies are discussed, too, considering the role of nanotechnologies.

Titanium niobium nitride knee implants are not inferior to chrome cobalt components for primary total knee arthroplasty at medium-term follow-up.

Oxidized zirconium (Oxinium), titanium nitride (TiN) or titanium niobium nitride (TiNbN) coated implants became in recent years available for an increasing amount of total knee arthroplasty (TKA) systems. The hypothesis of this study was that the use of TiNbN-coated components would not lead to inferior results compared to conventional implants and that none of the metal hypersensitivity patients receiving TiNbN-coated implants would require revision for metal allergy. This retrospective study compared 53 Titanium Niobium Nitride coated TKA with 103 conventional chrome cobalt implants of the same design. Patients were evaluated at a minimal follow-up of 3 years. No differences in clinical, radiological or patient-reported outcome measurements were observed between these groups. A survivorship of 96% without differences in revision rates was observed at medium-term follow-up of 6.5years. Metal allergy leading to contact or generalized dermatitis after TKA is very rare and usually linked to chrome or cobalt hypersensitivity. Nickel release from knee implants has not been shown to lead to cutaneous symptoms, but unexplained pain and swelling, peri-prosthetic osteolysis and component loosening remain potential issues not fully understood. The use of coated implants eliminates this factor from the diagnostic equation in case of postoperative dissatisfaction. The use of titanium niobium nitride coated implants for primary knee osteoarthritis in self-reported metal hypersensitivity patients shows similar outcomes and survivorship rates as conventional chrome cobalt TKA, with no revisions for allergy at medium-term follow-up.

Single pot low float chromium tanning: Cleaner pathway approach to environment friendly leather manufacturing

Chromium tanning is the most essential and extensively used tanning process in leather manufacture that requires pre and post-treatment steps such as pickling and basification to stabilize the collagen in the skin matrix. The conventional chromium tanning process results in low chromium uptake. The unabsorbed chemicals end up in the effluent, directly affecting the environment. Stringent norms have been stipulated for the disposal of effluents containing chromium, total dissolved solids and chlorides, forcing tanners to explore low-waste and cleaner chromium tanning processes. A chemical mixture was formulated to overcome the issues associated with chromium tanning process, which leads to pickle and basification free single pot chromium tanning. The designed process reduces effluent load generation exhibiting nearly 99% chromium uptake, while the conventional chromium uptake is only about 69%. The experimental process results in more than 99% reduction in TDS, chlorides, and COD load compared to the conventional tanning process. Also, the experimental leather possesses good thermal stability and physical strength comparable to the conventional leathers. Thus, the present research work provides an option for cleaner tanning technology to reduce water and chemical load, and the system is environmentally friendly.

Preparation and Characterization of the Cr-Nanodiamonds/MoN Coatings with Performant Mechanical Properties

This paper presents the results of a study on the preparation and characterization of a Cr-DND/MoN detonation chromium-nanodiamond coating deposited on cemented tungsten carbide (WC–3 wt.% Co) mill blades using Arc-PVD and electrodeposition methods. The physical and mechanical characteristics of the coatings were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), XRD analysis, Raman spectroscopy, micro-identification, and scratch test (evaluation of the coating adhesion). It was shown that the Cr-DND/MoN coating consists of successive layers of Cr-DND (top), Cu (middle) and MoN (bottom) with separate phases of γ-Mo2N, α-Mo, α-Cu, Cr-DND and nanodiamonds. The Cr-DND composite electrochemical coating (CEC) was deposited from the conventional chromium plating electrolyte with the addition of nanodiamonds. The copper interlayer was deposited by the Arc-PVD method on the surface of the MoN coating to improve the adhesion strength of the Cr-DND CEC. The coating showed an optimum microhardness of about 14 ± 1 GPa and good adhesion with a critical load Lc of about 93 N. In addition to the expected experimental results, the coating has high wear resistance, confirmed by scratch tests.

In vitro comparison between some mechanical properties of CAD/CAM polyetheretherketone and conventional cobalt chromium frameworks in removable partial denture

In vitro comparison between some mechanical properties of CAD/CAM polyetheretherketone and conventional cobalt chromium frameworks in removable partial denture

Fabrication of macrocrack-free thick chromium duplex plating for remanufacturing applications

The remanufacturing process of a hydraulic cylinder rod becomes a challenging prospect in the industrial sector producing heavy equipment. That is because remanufactured components can have the same product quality as new components with a more economical price. Hard chromium electrodeposition is a well-known technique to provide a protective coating for the cylinder rod so that it has favorable wear and corrosion resistance properties. Associated with remanufacturing applications, the used chromium plating covering the cylinder rod should be removed first before applying the new chromium one. Whereas the removal process often slightly consumes the base metal and fresh thicker chromium should be deposited in order to preserve its original diameter. The main problem is that the thick chromium may experience macrocrack after the baking process at 200 °C. Hence, the observation of as-plated and as-baked thick and hard chromium deposit properties is the novelty of this research. In this work, the thick and hard chromium plating over a flat carbon steel substrate was produced by the electrodeposition method. A conventional single-layer chromium deposit with a plating current density greater than 40 A/dm2 shows macrocracks after the baking process at 200 °C for an hour. For the chromium duplex plating composed of two Cr layers, the maximum thickness of the deposit was 261.0±8.5 microns, and the macrocrack was observed. Meanwhile, the as-baked duplex chromium plating composed of a polished Cr-C layer and a Cr layer has a microcrack density of 337±8 cracks/cm and hardness of 924.8±22.2 HV0.3 without macrocracks. EPMA characterization confirmed the presence of a carbon element in the Cr-C layer, and it is presumed due to carbon co-deposition from formic acid additives.

Synergistic Protection of Mild Steel in Sodium Chloride Solutions Using Mixtures of Sustainable Corrosion Inhibitors

Mild steel material has broad application in marine construction, due to their availability, low cost, and high tensile strength. Nevertheless, the major limitation of mild steel is its low corrosion resistance. The use of eco-friendly inhibitors in protecting mild steel from aggressive media is one of the cheap and practical means competing with conventional phosphate and chromate inhibitors. Herein, the synergism corrosion inhibition effects between key lime and chlorpheniramine drug were examined as sustainable inhibitors for mild steel in 24.5 M NaCl solutions through electrochemical measurement, and morphology of the same was characterized using scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM/EDX). The electrochemical investigations revealed that in the presence of 2ml key lime and 8ml chlorpheniramine drug the optimum inhibitive efficiency of 81.82% was achieved, this is connected to the protecting layer build-up on the surface of the mild steel, thus, blocking the harsh ion diffusion pathway. The polarization plot shows that the inhibitors complex the deposition led to the corrosion inhibition mixed-type mechanisms. The films formed on the mild steel surface were proved by the SEM/EDX result. The adsorption result shows that the inhibitors fit the Langmuir adsorption isotherm. Keywords: Synergistic effect, sustainable corrosion inhibition, NaCl solution, electrochemical techniques, mild steel

Bridging-induced densification strategy based on biomass-derived aldehyde tanning integrated with terminal Al(III) crosslinking towards high-performance chrome-free leather production

Chrome-free leather manufacturing has been acknowledged as a desirable option to eliminate potential environmental and human health risks of conventional chrome tanning. This work applied a sequential bridging-induced densification strategy to produce high-performance chrome-free leather with high crosslinking density derived from the biomass-derived aldehyde (BAT) crosslinking (BAT tanning of leather), followed by terminal Al(III) crosslinking (TAC). The TAC conditions for BAT tanned leather were optimized and the results suggested that the optimized conditions were as follows: the fixation pH was 4.2, the pre-penetration time was 180 min, the fixation temperature was 40 °C, and the dosage of the aluminum tanning agent (ATA) was 0.5% (based on Al2O3). Under the optimized conditions, the resultant BAT-TAC crust leather exhibited favorable overall performances compared with BAT crust leather in terms of higher hydrothermal stability, mechanical strengths, more pleasant uniform color, and comparable smooth grain surface. The obtained high-performance chrome-free leather is scalable, providing an avenue for designing and rationalizing other engineering technology towards high-performance eco-leather production.