Conventional Finishing Research Articles

An eco-friendly approach of preparation electric-driven thermochromic fabrics based on foam finishing

The novel strategy to endow Janus fabric with double-sided dual functions based on foam finishing was reported, which is an energy-efficient and environmentally-friendly method. The wet-state foam infiltration mechanism on the fabric surface was investigated, and the stability of the foam in solution was analysed in relation to surface tension and viscosity, as well as the loading capacity of the functional particles and the effect on fabric properties. And the controlled discoloration Janus fabric, driving by voltage, has been successfully created. The fabric shows remarkable electrothermal color-changing properties and wearability, and can be self-supplied with Joule heat to meet the demand of color change at any time: the temperature of the Janus fabric rapidly increases from room temperature to over 53.6 °C in 15 s at the applied voltage of 8 V, and the fabric temperature can be adjusted in the range of 20–62.5±3℃ at the voltage of 0–8 V. The fabric color can be transformed from blue to white within 6 s, and it can restore the color after 10 s of power off. Besides, the Janus fabric has excellent flexibility and resistance to heating fatigue, which can withstand 1000 bending cycles, and it was found that the Janus fabric has excellent temperature and color stability after 300 heating/cooling cycles and 6 hours of continuous energization. Compared to conventional finishing, the foam-finished Janus fabric not only possesses greater air permeability and handling properties, but also more energy savings. The experimental results show that the study of foam finishing is useful for expanding the application of surface science in fabric performance enhancement and provides a valuable reference for the green and smart development of textiles.

Review of surface roughness and material removing rate on abrasive flow machining process

Every day, advancements in manufacturing technology research and innovation yield a highly finished surface with lower labour and machining costs. The conventional materials that were frequently employed in the chemical, automotive, and aerospace industries have been replaced by materials like ceramics, metal matrix composites, polymers, and super alloys. The AFM technology is capable of maintaining precision, reliability, and adaptability across adverse range of applications. Internal parts, through holes, intersecting holes, and freeform surfaces that are challenging to finish with other conventional finishing techniques can all be polished and deburred with AFM. The current study aims to determine the process variables that have a major impact on the change in surface roughness of the inner, outer, and side surfaces as well as the amount of material removal. These parameters include abrasive mesh size, abrasive concentration in media, and the number of passes. A review of published technical articles on the AFM process is attempted in this article, and the studies are divided into four categories: experimental setups, abrasive media, modelling and optimisation, and applications of the AFM process. The review article provides fresh directions for future investigation. Page layout

Development of a New Collagen Gel Product for Leather Finishing.

Leather finishing is a critical process in the leather industry, as it significantly influences the final appearance, durability, and quality of leather products. Traditional leather finishing techniques often involve the use of synthetic chemicals, which may lead to environmental concerns and potential health hazards. In this study, we investigate the feasibility and effectiveness of a new collagen-based product for leather finishing. Collagen, a natural protein found abundantly in animals, has shown promise as an environmentally friendly and sustainable alternative for leather finishing. The new collagen gel product obtained from bovine hide waste by using an alkaline extraction method with lime was functionalized through an enzymatic treatment that allows to achieve a finishing product suitable for coating formulations, and at the same time, a biodegradable finishing. The collagen gel product was optimized by varying parameters, such as temperature, pH, and enzyme quantity. The optimized collagen gel product exhibits a wide particle size range and retains the triple-helical structure of collagen. The leather samples treated with the collagen gel product show enhanced properties compared to those with conventional finishes. The results show that the collagen gel product enhances water vapor permeability, color stability, and touch in the finishes. However, a low resistance to wet rubbing is obtained; therefore, it is necessary to study how to improve this parameter.

APPLICATIONS OF GREEN CHEMISTRY PRINCIPLES IN TEXTILE WET PROCESSING

The conventional finishing and dyeing processes practiced in the textile industry have a huge impact on the environmentand human health. This impact is due to the use of toxic chemicals, huge amounts of water usage, discharge of theeffluents generated by the textile industry in the water bodies, inefficient treatment of the discharged, water,atmospheric emissions and high energy consumption. The aim of the present study is to discuss the applications of greenchemistry principles in eco-friendly textile wet-treatment processes. This paper discusses the use of enzymes(biochemical approach) and physical treatment processes like ultraviolet radiation, plasma, and ozone technology. In caseof dyeing it discusses the use of natural dyes and technologies like Air Dye, ultrasonic, microwave, plasma, supercriticalCO2, electrochemical and Nano-DyeTM.

Determination of dye uptake in leather coatings for waterless leather dyeing by ScCO2 impregnation

During leather finishing the surface of leather is coated with coloured binder systems. In conventional finishing, two to five grams of dyestuff are used per square foot of leather. Due to so-called overspray, 40–60 % of dyestuff is lost. To increase resource efficiency, we examine the impregnation of dyestuff-free leather coatings using supercritical CO2 at 100 bar and 40 °C as a solvent for Solvent Red 111. The focus of the investigation is the effect of the layer thickness on the colour intensity. Furthermore, the dyestuff absorption capacity of the binder layer is determined. As result, a layer thickness of 23 µm allows the maximum achievable colour intensity. The dyestuff absorption capacity at this thickness is 35 mg of dyestuff per square foot of leather. This results in a saving potential for dyestuff of over 95 %.

Parametric investigation and optimization of revolving tools-based magnetorheological finishing process for external cylindrical surface of printing machine roller made of copper

The cylindrical copper rollers are an essential part of the printing process. The copper roller needs to be finely finished to ensure the even distribution of the colors. Fine and precise polishing of cylindrical copper rollers is challenging using conventional finishing procedures because of their ductility and low hardness. Therefore, the magnetorheological finishing process based on three revolving flat-tip tools has been used to meet this precise requirement. The optimized parameters were found as current 3.5A for the electromagnet, rotating speed of the workpiece 510 rpm, revolving speed of the tools 35 rpm, working gap 0.7 mm and feed rate 150 mm/min for maximum percentage reduction in the surface roughness of copper roller. After 4 h of finishing with the optimal parametric settings, the Ra, Rq, and Rz values were reduced to 0.08, 0.1, and 0.67 μm from the initial values of 0.375, 0.527, and 1.96 μm, respectively, across the copper roller surface. Surface roughness profiles, SEM, and mirror-image tests reveal the superiority of the magnetorheologically finished roller surface compared to the unfinished one.

Evaluation of EDM inclusion into the conventional polishing of printed Co-Cr alloy by selective laser melting

Objective: The selective laser melting (SLM) technique used in manufacturing results in a rougher surface that requires more satisfying processing than conventional hand-finishing operations. The electro discharge machine (EDM) has various possibilities in the adjustment of surfaces. The present study assesses whether the participation of the EDM technique with the conventional finishing and polishing methods enables surface improvement for the Cobalt- Chromium alloy fabricated by SLM. Material and Methods: Twenty discs of cobalt chromium alloy were fabricated by SLM, divided equally into two groups: (TF) control group for finishing and polishing in the conventional method in accordance with the manufacturer’s recommendations; and (EF) group for conducting polishing incorporating the EDM method. Results: The EF group recorded the lowest mean value of surface roughness and the highest mean value of micro hardness compared to the TF group. Furthermore, statistically significant differences (P < 0.05) were found for surface roughness as well as micro hardness. Conclusion: Reliance of the electric discharge machine proactively within finishing and polishing procedures promotes competence in the conventional polishing method and improves the surface properties of cobalt chromium alloy printed by SLM technology. KEYWORDS Dental finishing; Cobalt-chromium alloy; Selective laser melting; Electric discharge machine; Additive manufacturing.

Magnetorheological Finishing of Chemically Treated Electroless Nickel Plating

Electroless nickel plating with a nanofinished surface is used in space mirrors, automobile parts, aircraft components, optical instruments, and electronic equipment. Finishing of these components using conventional finishing techniques is limited due to size, shape, material, and process constraints. This work reports the nanofinishing of electroless nickel-plated surfaces using a magnetorheological finishing process where the surfaces are pre-treated with chemicals. The chemicals used in this work are hydrogen peroxide (H2O2) and hydrofluoric acid (HF). The effect of exposure time and concentration on the microhardness and roughness is studied to understand the surface chemistry after chemical treatment. The hydrogen peroxide forms a passivated layer, and it helps in easy material removal. Hydrofluoric acid improves surface quality and also helps in the removal of contaminants. The finished surface is characterized to understand the effect of chemical treatment on the finishing rate and surface topography. Normal and tangential forces are mainly affected by the hardness and surface condition after the chemical treatment. The best combination of parameters (chemical treatment with 1% HF for 30 min) was obtained and finishing was carried out to obtain a nanofinished surface with its areal surface roughness (Sa) reduced to 10 nm.

Assessment of the Ultrasonic Machine for Surface Finishing of 3D-Printed Cobalt-Chromium Alloy by Selective Laser Melting Technology

The selective laser melting (SLM) system reaches the status of a contender with the traditional casting of dental alloys, with the essential drawback that it is conducive to roughness, making surfaces difficult to finish by the conventional method. Ultrasonic machines (USM) are instrumentally sensible for processes involving metal surface adjustments. This study aims to assess the surface roughness for SLM by using USM instead of conventional finishing. The discs of cobalt chromium alloy were printed by SLM (n = 20) and evenly divided into two groups: one for finishing in compliance with the manufacturer's standard procedure, and the other for employing USM. The specimens were evaluated using the Surface Roughness Test, and the data was analyzed using the t-test. Highly significant differences were found at P < 0.01. Furthermore, the mean value accounted for a low level of readings (Ra) in the USM group, which amounted to 1.707, and with regard to the control group, it was 4.539. Ultrasonic finishing processes promote the competence of the finishing procedure and improve the surface quality for dental cobalt chromium alloys that are printed by SLM technology.

Improving the surface integrity of additively manufactured curved and inclined metallic surfaces using thermo-electric energy assisted polishing

Laser powder bed fusion (LPBF) is an advanced layer by layer manufacturing process gaining increased interest in industrial sector owing to its complex design flexibility. However, the parts produced using LPBF are not directly used in practical applications due to the geometrical inaccuracy and poor surface quality resulting from surface irregularities and defects. The established methods for post-processing LPBF parts/components such as laser polishing, abrasive polishing, chemical polishing and conventional finishing methods have inherent limitations depending on the variation in geometric shape/profile of the components. Hence, the present study analyses the effectiveness of a low energy wire electrical discharge polishing (WEDP) method in improving the surface quality and form accuracy of curved and inclined AlSi10Mg samples fabricated using laser powder bed fusion (LPBF). A geometrical model is proposed in the study for estimating the depth of material removed in each polishing pass. The developed model is capable of predicting the number of polishing passes required for the removal of irregularities on the surface. The geometrical form accuracy of metallic AM samples was improved significantly after WEDP with more than 68 % reduction in cylindricity error and 75 % reduction in flatness error. In addition, the samples exhibited uniform surface finish after WEDP with ~50–60 % reduction in as-built roughness. The SEM analysis conducted in the study reveals that WEDP is capable of eliminating the stair stepping surface defect with enhancement in geometrical profile. Furthermore, the EDS analysis confirmed the formation of oxide layer on the LPBF surface after WEDP post-processing.

Development of semi-empirical model to estimate surface finish of Inconel-625 alloy in extrusion honing process

It is vital and obvious to impart the required quality of surface on the interior and exterior areas of the machined component. Required texture can be imparted on the outer surfaces by conventional finish machining process like grinding, honing etc. The difficulty arises while finishing core inner region/miniature component such as nozzles, injector valves etc. This difficulty is addressed by EH process. It is a finish machining technique of inducing required surface texture by flowing the pressurized semi viscous carrier medium with SiC across the restricted passage. As a result, due to abrasion finishing action takes place by removing the material in small amount. The current study proposes a semi empirical model for surface finish Ra in extrusion honing process. The model is developed by Buckingham's π theorem and comparative assessment of the developed model by experimental results. By considering the stiffness of Inconel-625 alloy and opted process parameters such as number of passes, volume concentration and mesh size of abrasives. The final texture resulted due to EH process is described by performing SEM study. Finally, this work reiterates and traces the experimental results by the estimated values of non-dimensional model.

The perenity of the indirect bonded restorations : the «no-finishing concept»

Over the past 30 years, the development of adhesive techniques has reduced the biological cost of bonded indirect restorations (in/onlays and veneers). However, the procedures for bonding to dental tissue are still more demanding than those for conventional cemented prostheses. One of the keys to the durability of indirect adhesive restorations is their ability to prevent bacterial plaque from adhering to their surface. With this in mind, this article describes a clinical protocol for obtaining the smoothest possible prosthetic margins, without resorting to conventional finishing and polishing techniques, which are tedious and time-consuming.

Water Efficient, eco-friendly and Effluent Free Nano bubble Finishing of Cotton Fabric

ABSTRACT Existing textile exhaust finishing methods require higher liquor ratios, such as 1:5 and 1:10, leading to energy wastage, chemicals wastage, and higher effluents. However, the nanobubble technique can reduce the liquor ratio to 1:1, resulting in water savings, energy savings, and zero liquid discharge. Nevertheless, production of the nanobubbles for a range of finishes and their successful application onto the textile is a difficult and challenging task. For the first time, this article successfully reports the development and application of nanobubbles at the extremely low liquor ratio of 1:1 for the five most commonly used textile finishes, which include resin, softener, soil release, oil and water repellent, and antimicrobial finishes onto the cotton fabric. In addition, this research compares the performance of the nanobubble finishing at a liquor ratio of 1:1 with higher liquor ratios of 1:5 and 1:10 for all five finishes. The results showed that optimized nanobubble finishing exhibited comparable key performance with reference to liquor ratios of 1:5 and 1:10 related to each finish category. However, the physical properties of cotton fabrics, such as tensile strength, tear strength, bending length, and air permeability, were better for nanobubble technology as compared to conventional finishing.

Multiobjective Optimization of Laser Polishing of Additively Manufactured Ti-6Al-4V Parts for Minimum Surface Roughness and Heat-Affected Zone.

Metal parts produced by additive manufacturing often require postprocessing to meet the specifications of the final product, which can make the process chain long and complex. Laser post-processes can be a valuable addition to conventional finishing methods. Laser polishing, specifically, is proving to be a great asset in improving the surface quality of parts in a relatively short time. For process development, experimental analysis can be extensive and expensive regarding the time requirement and laboratory facilities, while computational simulations demand the development of numerical models that, once validated, provide valuable tools for parameter optimization. In this work, experiments and simulations are performed based on the design of experiments to assess the effects of the parametric inputs on the resulting surface roughness and heat-affected zone depths. The data obtained are used to create both linear regression and artificial neural network models for each variable. The models with the best performance are then used in a multiobjective genetic algorithm optimization to establish combinations of parameters. The proposed approach successfully identifies an acceptable range of values for the given input parameters (laser power, focal offset, axial feed rate, number of repetitions, and scanning speed) to produce satisfactory values of Ra and HAZ simultaneously.

Magnetorheological finishing of aluminium cylindrical roller for enhanced performance of printing operation

Aluminium is the most versatile engineering material for various industries, such as transport, machinery, metallurgy and printing. The aluminium cylindrical roller plays a significant role in the printing machine. In order to evenly distribute the pressure and for accurate tolerances roller needs to be perfect and uniformly finished. Owing to their ductility and lesser hardness, it is difficult to achieve uniform and fine finishing by conventional finishing methods. The rotary magnetorheological (MR) method is established to satisfy this requirement. The MR polishing fluid composition is initially analysed in order to obtain a fine finish. The central composite design was employed to optimize the finishing parameters. The batch gradient descent algorithm is used to validate the RSM optimization of process parameters. Batch gradient descent gives the mathematical model which validates the RSM mathematical model. The scan electron microscopy, reflectivity test and surface roughness profile check were carried out to track the surface texture and the cylindrical aluminium roller's ruggedness. The standard deviation test is performed to measure the uniformity of the finished surface and demonstrate that the uniformity of the finished surface which is increased. Geometric measurements are tested by the way of the surface waviness measurement. The results of earlier process parameters and with addition of reciprocation of work-part is compared and experimentation performed on 120 mm long and 25 mm diameter of the aluminium cylindrical roller with 30 mm length for each trial.

Photochromic Microcapsules for Textile Materials by Spray Drying—Part 3: Application of Photochromic Microcapsules on Cotton Fabrics

Photochromic textiles, a class of functional textiles, have a color build up feature under ultraviolet light irradiation. However, photochromic dye application onto textile materials by conventional finishing techniques has difficulties due to their low water solubility and low affinity to the textile materials. Encapsulation technology could be used to overcome these problems in the production of photochromic textile materials. This article, which is the third in a three-part series, deals with the application of photochromic dye microcapsules produced by a spray drying method onto cotton fabrics. The photochromic dye microcapsules were applied onto cotton fabrics by a pad–dry–cure process. Color build up and ultraviolet transmittance of the resultant photochromic fabrics were evaluated after the application and consecutive washing. Moreover, the fatigue resistance of the photochromic fabrics was studied and the effects of the incorporation of hindered amine light stabilizers into microcapsules were investigated. Ultraviolet protection factor values of the samples were found to be 50+ even after 20 washing cycles. It was shown that the photochromic fabrics have a loss of 10% in ultraviolet protection factor values and 20% in color values after 20 ultraviolet irradiation cycles and the fatigue resistance of the photochromic dye capsules improved with the use of hindered amine light stabilizer compounds during microcapsule production.

Structuring by laser remelting as a method for waviness reduction on additive manufactured parts

The surface roughness of parts manufactured by laser powder bed fusion (LPBF) is often not sufficient for the intended application. Therefore, surface finishing is necessary. Conventional finishing techniques have many disadvantages like accessibility of complex geometries, high time and cost consumption and a negative environmental impact due to the use of abrasives. As a solution laser polishing is investigated. In this study it was found that surface roughness of LPBF parts up to a spatial wavelength of 0.5 mm can be reduced by ∼96% with laser polishing, while waviness can only be reduced by ∼55%. To further reduce waviness, structuring by laser remelting (WaveShape) is investigated. The basic idea is to structure the inverse of the initial structure and thus to “de-structure” the waviness. A structured profile of a laser polished LPBF surface is “de-structured” with a variation of process parameters. The results show the potential of a waviness reduction of 85%.

Study on Finishing of Polychlorotrifluoroethylene Resin by Magnetic Abrasive Finishing Process with Renewable Abrasive Particles

Polychlorotrifluoroethylene material is used in industry as a material with excellent insulation, impact resistance and acid and alkali resistance. In this study, we used a magnetic abrasive finishing process with renewable abrasive particles to finish the surface of the polychlorotrifluoroethylene resin plate. Magnetic Abrasive Finishing (MAF) process is a technology that uses flexible magnetic brushes to improve the surface quality of materials. The performance of the magnetic brush is a key factor in surface finishing. In conventional MAF finishing, the number of abrasive particles in the magnetic brush is limited, and the position of the abrasive particles is relatively fixed, which will cause the cutting edge of the abrasive particles to gradually become dull and the finishing efficiency gradually decreases. This paper research the characteristics of the MAF process with renewable abrasive particles. This MAF process has a circulating system that uses a conveyor belt to renew abrasive particles. We use the polychlorotrifluoroethylene resin plate as the experimental processing object to conducted finishing experiment. And the surface roughness of the polychlorotrifluoroethylene resin plate is improved from 315 nm to 32 nm through this process.

Multifunctional Leather Surface Design by Using Carbon Nanotube-Based Composites.

This paper deals with original research in smart leather surface design for the development of multifunctional properties by using multi-walled carbon nanotube (MWCNT)-based nanocomposites. The conductive properties were demonstrated for both sheepskin and bovine leather surfaces for 0.5% MWCNTs in finishing nanocompositions with prospects for new material design intended for flexible electronics or multifunctional leathers. The photocatalytic properties of bovine leather surface treated with 0.5% MWCNTs were shown against an olive oil stain after visible light exposure and were attributed to reactive oxygen species generation and supported by contact angle measurements in dynamic conditions. The volatile organic compounds’ decomposition and antibacterial tests confirmed the self-cleaning experimental conclusions. Ultraviolet protection factor had excellent values for leather surfaces treated with multi-walled carbon nanotube and the fastness resistance tests showed improved performance compared to control samples. Scanning electron microscopy with energy dispersive X-ray (SEM-EDX), X-ray photoelectron spectroscopy (XPS), and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy analysis confirmed the influence of different leather surfaces on MWCNT dispersion with an effect on nanoparticle reactivity and efficiency in self-cleaning properties. Multifunctional leather surfaces were designed and demonstrated through MWCNT-based nanocomposite use under conventional finishing conditions.

Laser polishing of additive manufactured Ti6Al4V alloy: a review

Additive manufactured Ti6Al4V alloy has excellent comprehensive properties and has broad application prospects in the aerospace, biomedicine, and other fields. However, the fabricated components are too rough to use directly. So, a corresponding postprocess is needed urgently. The conventional finishing process cannot meet the requirements of green and efficient processing because of its time consumption, environmental pollution, and low productivity. Laser polishing, as a highly efficient and noncontact post-treatment technology, has attracted more and more attention in the polishing of additive manufactured Ti6Al4V alloy. The research of laser polishing of Ti6Al4V alloy in recent years has expatiated and includes laser polishing mechanisms, surface roughness and morphology, microstructure, mechanical properties, and finite element simulation analysis during laser polishing. Furthermore, the existing challenges of laser-polished Ti6Al4V alloy are summarized, and future development directions are proposed.