Metal-Free Combination Tanning with Replenishable Polyphenols and Marine Oil

Author(s):  
V. John Sundar ◽  
C. Muralidharan

In line with the resurgence of natural products in the global manufacturing industry, the leather industry is also relooking the increased use of organic materials. To exploit the benefits of the vegetable tanning materials and to couple with suitable organic material for overcoming the inherent shortcomings of vegetable tanning materials, studies were undertaken. Tanning materials like raw fish oil have advantageous properties to impart on leather such as softness, lightweight, and washability characteristics. Hence studies were undertaken on polyphenol-fish oil combination tannages. The quantities of wattle and fish oil and process conditions were standardized. The study indicated that the oxidation of fish oil could take place in the presence of vegetable tannins. The leathers tanned by this combination tanning system could be converted into garment leathers of rich shades and possessed good strength and physical properties. Propelled by encouraging results, investigations were also made on the nature of interaction between vegetable tannins and fish oil with collagen. It was also observed that the vegetable tannins probably do not hinder the oxidation of oil. To sum up, the study leads to the development of a viable, versatile organic tanning system to gain eco-acceptability for the leather manufacturing process.

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Anthony D. Covington ◽  
William R. Wise

Abstract In preparing the second edition of ‘Tanning Chemistry. The Science of Leather.’, the literature was updated and the content was revised and reviewed. Here, the new findings are presented and discussed. Notable developments include the necessary rethinking of the mechanism of sulfide unhairing because of new understanding of the aqueous chemistry of sulfide species. Revision upwards of the value of the second pKa for sulfide species ionisation means that S2− cannot exist in an aqueous medium, so the unhairing species in hair burn reactions is HS−. Although the technology remains the same, this means the mechanisms of associated reactions such as immunisation must be revised. Rawstock preservation has benefitted from studies of the potential role of materials from plants which accumulate salt, but which also contribute terpene compounds. There is also further discussion on the continuing issue of chromium (VI) in the leather industry. The application to processing of new solvents, ionic liquids and deep eutectics, is the coming technology, which offers transforming options for new chemistries and products. Renewed interest in vegetable tanning and methods of wet white processing are current trends. Also, within the topic of reagent delivery is processing in a solid medium of plastic beads. Graphical abstract


2018 ◽  
Vol 15 (30) ◽  
pp. 696-703
Author(s):  
H. D. CHIRINOS ◽  
J. A. BARRA ◽  
D. D. CRUZ ◽  
G. M. HUALLPAMAYTA

To improve the parameters of the transesterification process by the basic route for the production of biodiesel, crude fish oil (AP), obtained from the viscera of fish, and residual vegetable oils (AR) blenders were used. Because the AP contains high percentages of long chain polyunsaturated fatty acids that are responsible for its instability is that it was mixed with increasing percentages of AR. This translated into a higher conversion performance to biodiesel by the basic route, also depending on the level of free fatty acids. The index of methyl esters obtained from the blends and the original oils was analyzed. The calculation of the performance of each reaction is made based on the produced esters. The analysis is complemented by measuring the kinematic viscosity of the blends and the pure oils, as well as the biodiesel produced. The results showed yields higher than 90% when using the process of transesterification of the blends by the basic route. The standardization of blends by its acidity index is of great importance reaching a maximum value of 3.5 mg KOH/g. On the other hand, the viscosity of the biodiesel produced, from the blends, is kept within international standards; In addition, the process conditions are improved.


Author(s):  
João Sousa ◽  
José Ferreira ◽  
Carlos Lopes ◽  
João Sarraipa ◽  
João Silva

Abstract The continuous thrive for working safety, customer satisfaction and increasing profits for companies has led to numerous manufacturing and management strategies. One of the most promising strategies nowadays is Zero Defects that focuses on the elimination of defected parts in the manufacturing processes. The benefits of Zero Defect implementation in the manufacturing industry are mainly related to the reduction of scrap material, and everything that does not bring any added value to the product. The result is a reduction of the company’s expenditure for dealing with defective products. In spite the concept not being new, the practical application of such strategies were limited by technological constraints and high investment costs. With the Industry 4.0 evolution, some Zero Defects concepts are more accessible due to the availability of sensors and data related techniques such as Machine Learning and Big Data although a lot of work is still required for component integration to enhance the capability of the heterogeneous technologies. The quality of the steel tubes is evaluated by sampling and relies on the expertise of the operators for checking for nonconformities. When a defect is detected, the process parameters are adjusted based on prior experience. However, since this is a continuous process, the delay between the appearance of a defect in the process and its awareness leads to a considerable amount of produced scrap material. Worst-case scenario, the defective product can be delivered to the customer damaging the customers trust and leading to additional replacement costs. This paper addresses the application of the Zero Defects approach to the steel tube manufacturing industry. This approach is part of the Zero Defects Manufacturing Platform EU project that is based around a Service Oriented Architecture and microservices approach capable of building, running and managing specific use-case oriented software applications called zApps. The Zero Defects methodology to design a zApp based on key criteria for the steel tube industry is described. Additionally, the envisioned zApps to monitor all the produced steel tube during the manufacturing process are detailed. The inspection systems uses a scanning camera and a laser profile scanner to capture the steel tube defects during manufacturing and prior to packaging. Although the ultimate goal is to eliminate the cause of the defective products, the objective of the zApp is to increase the number of detections of defective products based on industry standards and reduce the amount of generated scrap material.


Author(s):  
David E. Lee ◽  
H. Thomas Hahn

Abstract Concurrent with the use of tailored materials for specific applications has been the understanding that a product’s design has a significant and measurable effect on manufacturing process cycle times and unit production costs. In order to reliably manufacture and assemble aircraft structures fabricated from composite materials on a cost-effective basis, an environment for virtual assembly production analysis is being developed. Within this environment, members of an aircraft’s integrated product development team can rapidly assess the impact of design decisions on individual assembly operations and overall aircraft assembly in a virtual manufacturing context. Effects related to joint design and component matings are measured based on force and process conditions as well as the types of tooling required for final assembly. By evaluating assembly production impacts early during product design, the costly design-manufacture-redesign cycle is redefined and recast based on the realities of manufacturing process constraints.


Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3982
Author(s):  
Inseop Yoon ◽  
Seongwoog Oh ◽  
Jungsuek Oh

This paper proposes a novel design approach for a thin lens with the aim of overcoming fineness limits in the commercial millimeter wave printed circuit board (PCB) manufacturing process. The PCB manufacturing process typically does not allow the fabrication of metallic patterns with a gap and width of less than 100 μm. This hampers expanding thin lens technology to 5G commercial applications, especially when such technology is considered for 60 GHz or higher frequency, which requires a finer gap and width of metallic traces. This paper proposes that problematic process conditions can be mitigated when a lens is designed by establishing single-polarized lumped element models where larger capacitance and inductance values can be obtained for the same patch and grid unit cells. While the proposed design technique is more advantageous at higher target frequencies, a 60 GHz application and a wireless backhaul system is selected because of a limited range of frequencies that can be measured by an available vector network analyzer. The required gap or width of metallic traces can be widened significantly by using the proposed single-polarized unit cells to acquire the same in-plane capacitance or inductance. This enables the lens operating at higher-frequency under the process limits in fabricable fine traces. Finally, the effectiveness of the simulated design procedure is demonstrated by fabricating a 60 GHz thin lens that can achieve a gain enhancement of 16 dB for a 4 × 4 patch antenna array with a gain of 16.5 dBi.


2020 ◽  
Vol 10 (10) ◽  
pp. 3633
Author(s):  
Luis Pérez ◽  
Silvia Rodríguez-Jiménez ◽  
Nuria Rodríguez ◽  
Rubén Usamentiaga ◽  
Daniel F. García

Intelligent automation, including robotics, is one of the current trends in the manufacturing industry in the context of “Industry 4.0”, where cyber-physical systems control the production at automated or semi-automated factories. Robots are perfect substitutes for a skilled workforce for some repeatable, general, and strategically-important tasks. However, this transformation is not always feasible and immediate, since certain technologies do not provide the required degree of flexibility. The introduction of collaborative robots in the industry permits the combination of the advantages of manual and automated production. In some processes, it is necessary to incorporate robots from different manufacturers, thus the design of these multi-robot systems is crucial to guarantee the maximum quality and efficiency. In this context, this paper presents a novel methodology for process automation design, enhanced implementation, and real-time monitoring in operation based on creating a digital twin of the manufacturing process with an immersive virtual reality interface to be used as a virtual testbed before the physical implementation. Moreover, it can be efficiently used for operator training, real-time monitoring, and feasibility studies of future optimizations. It has been validated in a use case which provides a solution for an assembly manufacturing process.


2019 ◽  
Vol 11 (9) ◽  
pp. 2560
Author(s):  
Hyun Ahn ◽  
Tai-Woo Chang

As the adoption of information technologies increases in the manufacturing industry, manufacturing companies should efficiently manage their data and manufacturing processes in order to enhance their manufacturing competency. Because smart factories acquire processing data from connected machines, the business process management (BPM) approach can enrich the capability of manufacturing operations management. Manufacturing companies could benefit from the well-defined methodologies and process-centric engineering practices of this BPM approach for optimizing their manufacturing processes. Based on the approach, this paper proposes a similarity-based hierarchical clustering method for manufacturing processes. To this end, first we describe process modeling based on the BPM-compliant standard so that the manufacturing processes can be controlled by BPM systems. Second, we present similarity measures for manufacturing process models that serve as a criterion for the hierarchical clustering. Then, we formulate the hierarchical clustering problem and describe an agglomerative clustering algorithm using the measured similarities. Our contribution is considered on the assumption that a manufacturing company adopts the BPM approach and it operates various manufacturing processes. We expect that our method enables manufacturing companies to design and manage a vast amount of manufacturing processes at a coarser level, and it also can be applied to various process (re)engineering problems.


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