Finishing Process Research Articles

Janus outdoor protective clothing with unidirectional moisture transfer, antibacterial, and mosquito repellent properties

Personal protective clothing with versatile and durable features is highly desirable for daily and specific environmental scenarios. Especially for outdoor workers or sports enthusiasts, prolonged outdoor exposure requires their clothing to be more functional to cope with a wide range of situations, such as heat stress in summer, odor generation after sweating, and mosquito bites. These not only reduce the wearing comfort of clothing, but also bring potential heat stroke, skin infections and diseases brought by mosquitoes. Currently, most outdoor protective clothes focus on a single function, such as waterproofing and UV protection and are not able to cope with the demand of multiple protections. In this paper, we developed permethrin-containing triblock cationic polymers (PTCPs) that can multi-functionalize outdoor clothing. Benefiting from their high affinity to polyester fibers, PTCP modified polyester yarns were obtained by an aqueous based finishing process. After that, a scalable machine-knitting fabrication technique is employed to fabricate Janus outdoor protective clothes (Janus-OPC). The as-prepared Janus-OPC exhibited excellent one-way moisture transfer properties (forward cumulative one-way transfer index (OWTI) of 924.23%, and backward OWTI of −690.52%), antimicrobial properties (97.73% and 99.72% against E. coli and S. aureus, respectively), and mosquito repellent properties (repelling rate of 76.19%). Moreover, the protective performance of the Janus-OPC was maintained after 50 times of equivalent home laundering cycles. This multifunctional protective clothing opens up a new direction for the next-generation outdoor wear.

Influence of Reverse Finishing on Characteristics of Drilling Surface

Aluminum alloys are often used in automobile and aircraft parts that require higher dimensional accuracy and durability. Drilling is often used in the machining process of these products and accounts for about 60% of the machining performed on these products. Deterioration of finishing surface accuracy in drilling causes problems such as decreased tool life due to wear and increased cost due to the introduction of the finishing process. The objective of this study is to evaluate the finished surface characteristics in the drilling of aluminum alloys using reverse finishing, with a focus on the cutting direction of finishing, with respect to the roughing direction. The torque and thrust force are smaller in reverse finishing than in forward finishing. The reduction effects of cutting force in reverse finishing were more significant when the finishing depth of cut was smaller in relation to the roughing-affected layer. Under conditions where the finishing depth was equal to or greater than the roughing-affected layer, it was possible to reduce cutting forces and improve surface roughness while obtaining compressive residual stresses equivalent to forward finishing.

Effect of YF3 Coating Process on Film Stress

YF3 rare-earth fluoride coating material has received wide attention as an alternative to ThF4 low refractive index material, but the film layer can be seriously affected due to the different coating processes. Therefore, to investigate the rules between the coating processes of YF3 rare-earth fluoride coating materials, YF3 thin films were coated with different deposition rates and substrate temperatures. The stresses of YF3 thin films under different processes were obtained by a thin film stress meter, and the microscopic morphology of the thin films was characterized by atomic force microscopy. The results show that: YF3 monolayer film is tensile stress; in the deposition rate between 0.5nm/s~1.5nm/s, with the increase of the coating deposition rate YF3 monolayer film stress tends to decrease, the roughness of the film is also gradually increased, and the overall thickness of the film surface decreases; in the substrate temperature is greater than 50 ℃, the film stress is significantly reduced.

Recent advances in nanobased flame-retardant coatings for textile fabrics

Textiles constitute a large percentage of the market due to its advantages such as being comfortable, available, diverse and easy to use, but because of its easier ignition and its thermal instability that hinder its use and that lead to a harmful effect on the environment and people. Thus, flame retardant materials have to incorporate on the textile fabrics as coating nanocomposites on their surface during finishing process or post-modification for integrating fire safety of textile fabrics. Hence, in this minireview brief classification of flame retardants based on nano-dimension for textile fabrics and their retardation actions are reviewed and discussed. Recent advances in nanoscale-based flame-retardant coatings for different textile fabrics were studied; the nanoparticles, nanotubes and nanosheets based flame retardants nanocoatings were investigated. The influence of flame retardants nanocoatings in other textile fabrics features such as antibacterial, tensile strength and conductivity were also highlighted. Additionally, synergistic flame retardancy effect of different nanomaterials with other ingredients are also studied. Moreover, the commonly flame retardancy actions for green flame retardants nanocoatings for textile fabrics were discussed. Moreover, future prospects for improving the fire safety for textile fabrics were summarized.

Numerical Analysis of the Blade Coating Process Using Non‐Newtonian Nanofluid with Magnetohydrodynamic (MHD) and Slip Effects

AbstractThe coating process is widely used in various industries to enhance the production quality and efficiency. This study gives a comprehensive analysis of non‐isothermal blade coating of non‐Newtonian nanofluid incorporating magnetic, thermophoresis, and Brownian effects. The mathematical equations derived from mass, momentum, and energy conservation laws are initially streamlined by means of lubrication approximation theory (LAT). Subsequently, these dimensionless equations are solved in dimensionless form numerically using fourth order Runge–Kutta and Newton–Raphson methods. This study includes the effects of the slip parameter, magnetohydrodynamic (MHD) and other material parameters on the coating thickness (), blade load, velocity, temperature, concentration, and pressure profiles through graphs and tables. The velocity of molten polymer increases near the substrate while it decreases near the blade surface as the slip parameter increases. The temperature distribution increases as the Brinkman number rises, with the maximum temperature occurring in the nip region of the flow. The coating thickness and load‐carrying force for both plane and exponential coater increase with higher values of the magnetohydrodynamic (MHD) parameter.

Laser cladded Co08–xTi3AlC2 coatings: Microstructure, corrosive–wear and electrochemical corrosion

MAX phase played the positive role during the corrosive–wear process of metal coatings, and Ti3AlC2 was added into Co08 coating by laser cladding to improve its corrosive–wear and electrochemical properties. The effects of Ti3AlC2 mass fraction on the corrosive–wear and electrochemical properties of obtained coatings in 3.5 % NaCl solution were investigated using a reciprocating wear tester and electrochemical workstation, respectively. The results show that the Co08–xTi3AlC2 coatings are composed of Co (Ni, Cr, W, Mo), AlFe and Ti3AlC2 phases, and their hardness is increased with the Ti3AlC2 mass fraction. The average coefficients of friction of Co08–5 %Ti3AlC2, –10 %Ti3AlC2 and –15 %Ti3AlC2 coatings are 0.56, 0.47, and 0.41, respectively, and the corresponding wear rates are 418.99, 389.67, and 339.33 μm3 N−1 s−1, respectively, showing that the Co08–15 %Ti3AlC2 coating has the best friction reduction and wear resistance among the three kinds of coatings. The wear mechanism of Co08–5 %Ti3AlC2, –10 %Ti3AlC2 and –15 %Ti3AlC2 coatings are abrasive wear, adhesive wear, and abrasive wear/adhesive wear, respectively. Moreover, the corrosion resistance of Co08–xTi3AlC2 coatings is increased by the Ti3AlC2 mass fraction, which is attributed to the protection role of corrosion products by the addition of Ti3AlC2.

Study on temperature and hardness behaviors of Al-6060 alloy during magnetic abrasive finishing process using artificial neural networks

Magnetic Abrasive Finishing (MAF) revolutionizes surface finishing by utilizing magnetic fields to apply pressure, ensuring exceptionally high-quality surfaces. Its potential for ultra-precise finishing with fine magnetic abrasives is particularly noteworthy. This study analyzes subsurface temperature dynamics during the MAF process on Al-6060, recognizing temperature's pivotal role in shaping surface texture and mechanical-chemical properties. Unbonded magnetic abrasives containing SiC were used without lubrication or coolants in experimentation. Experimental parameters, including machining gap, abrasive weight, voltage, and rotational speed, were systematically varied using a Box-Behnken Design of Experiments. An artificial neural network facilitated comprehensive data modelling, enabling a detailed parametric study. Post-processing surface characterization provided crucial insights into the impact of surface temperature rise on surface finish and hardness. This holistic approach enhances understanding of temperature's influence on MAF efficacy and its outcomes on Al-6060 surfaces. Experimental findings demonstrate MAF's effectiveness in achieving low-temperature finishing of Al-6060, with a maximum surface temperature of 36 °C. ANOVA analysis quantitatively determined that voltage has greatest influence (55.56%), followed by abrasive weight (20.00%) and machining gap (13.89%), with rotational speed having the least impact (2.22%). Qualitatively, the developed ANN model accurately predicted changes in surface roughness (ΔRa), temperature (ΔT), and hardness (ΔH), with maximum errors of 4.107%, 5.588%, and 6.680%, respectively. XRD analysis provided quantitative evidence of SiC diffusion into the surface, resulting in a hardness increase from 2.7 HV to 5.6 HV. Additionally, chemical substrates deposition, such as silicon carbide, kaolinite, iron silicide, and cristobalite, elucidated chemical-mechanical interactions during the process at such low temperatures.

A Comparative Study of B Cell Blast Isolation Methods from Bone Marrow Aspirates of Pediatric Leukemia Patients.

Density gradient centrifugation is a conventional technique widely utilized to isolate bone marrow mononuclear cells (BM-MNC) from bone marrow (BM) aspirates obtained from pediatric B-cell acute lymphoblastic leukemia (B-ALL) patients. Nevertheless, this technique achieves incomplete recovery of mononuclear cells and is relatively time-consuming and expensive. Given that B-ALL is the most common childhood malignancy, alternative methods for processing B-ALL samples may be more cost-effective. In this pilot study, we use several readouts, including immune phenotype, cell viability, and leukemia-initiating capacity in immune-deficient mice, to directly compare the density gradient centrifugation and buffy coat processing methods. Our findings indicate that buffy coat isolation yields comparable BM-MNC product in terms of both immune and leukemia cell content and could provide a viable, lower cost alternative for biobanks processing pediatric leukemia samples.

To Enhance the Performance of LiNi0.5Co0.2Mn0.3O2 Aqueous Electrodes by the Coating Process.

The Li+/H+ cation exchange reactions occur when the cathode is exposed to water and can cause the degradation of battery performance, posing a significant challenge in the preparation of cathode aqueous electrodes. In this study, kh570 [3-(trimethoxysilyl)propyl methacrylate] is used to coat and modify the surface of LiNi0.5Co0.2Mn0.3O2 cathode particles. During the coating process, kh570 undergoes hydrolysis to generate silanol groups, which are subsequently bonded onto the surface of cathode particles and undergo self-polymerization through condensation reactions. As a result, a coating layer forms on the surface of the cathode. This change alters the surface properties of the cathode particles from hydrophilic to hydrophobic, thereby increasing their resistance to water. The coating layers reduce direct contact with water and minimizes internal particle microcracks formation in aqueous electrode processing. After the preparation of aqueous electrodes, the modified cathode exhibits lower transfer resistance and lower polarization, improving both the current rate performance and the cycling performance of the battery.

Effect of injection compound rolling process and curdlan gel on water retention of sauced beef

Research background and significance: Under the current development trend in the field of global food science and technology, consumers' requirements for food safety, nutritional value and sensory quality are increasing, prompting the innovation of food processing and preservation technology to become the core of the industry development. In the production of traditional food spiced beef, how to ensure the yield and quality of spiced beef is the focus of the spiced beef market. By adding edible glue can gain weight, thereby improving the yield, but previous studies have shown that carrageenan, seaweed extract and so on seriously affect the sensory quality of marinated beef, especially causing its juice oozing, colloidal attachments oozing and so on. Research content: Through the systematic study of the application of curdlan gel in the processing of brine injection spiced beef, the specific effects of curdlan gel on the water retention and sensory quality of spiced beef were discussed in this study. (1) Sensory optimization injection rolling composite curing process. The experiment was carried out with beef tendinous meat and a series of auxiliary materials, using fine processes and methods, including saline injection, rolling salting, cooking treatment, etc., and then conducting sensory evaluation. (2) Compare the quality difference of curdlan gel 1 and 2. Determination of gel strength and optimization of water retention of stewed beef were carried out. Single factor ANOVA test was used to determine the optimal dosage of curdlan gel. The results showed that the water retention of beef with brine injection could be enhanced significantly when the dosage was 2%, respectively. Under the optimal process conditions, the sensory score of brined beef was 85.4 points. Through this study, important scientific and technological findings were obtained, which did not mean that the higher the concentration of curdlan gel, the better the water retention, on the contrary, the higher the concentration of its water retention would be affected but would decrease. This research not only expands the application range of curdlan gel in the food industry, but also provides new technical solutions and theoretical support for the innovation and development of meat processing technology, and meets the needs of consumers for high-quality meat products.

Modeling and experimental study of surface roughness in smart MR fluid-based finishing process

Ball-end magnetorheological finishing (BEMRF) is a high-efficiency nano-finishing technology based on smart magnetorheological fluid to polish complex materials precisely. The surface roughness can be linked with the experimental data to understand the finishing mechanism based on advancements in manufacturing automation and the prediction of material removal. This study proposes a mathematical model to predict surface roughness, helping to understand the effects of various process parameters on surface quality during the BEMRF process. This study adds value to practitioners by providing a mathematical model to predict the optimum parameters for attaining the desired surface finish in BEMRF polishing.

Fuzzy Logic Based Model to Predict Surface Roughness of Si(100) Wafer Using Preliminary Experimental Data Obtained From Single Pole Magnetic Abrasive Finishing Process

Fuzzy Logic Based Model to Predict Surface Roughness of Si(100) Wafer Using Preliminary Experimental Data Obtained From Single Pole Magnetic Abrasive Finishing Process

Construction Technology of Steel Structures in Large Public Buildings

With the continuous development of the Chinese economy and the rapid development of large public buildings, the application of steel structures in large buildings is gradually increasing. The use of steel structures is crucial for meeting the needs of large-span, super high-rise buildings, rapid construction, and achieving sustainable development of buildings. Therefore, studying and analyzing the construction technology of large-scale building steel structures has important practical significance. This study is based on a library construction project, focusing on the installation of embedded bolts, steel columns, steel beams, and high-strength bolts in the construction of large building steel structures, as well as the technical schemes and construction processes of welding, anti-corrosion coatings, and fireproof coatings. I hope to provide reference and suggestions for actual construction.

Impact of Laser Shock Peening Without Ablative Coating Process on the Surface Characteristics and Wear Behavior of High-Speed Steel

Impact of Laser Shock Peening Without Ablative Coating Process on the Surface Characteristics and Wear Behavior of High-Speed Steel

Nano-structure and hydrophobicity co-determined barrier properties of corrosion protective ZnAl-LDH film in atmospheric environment

Salt spray is prone to convert superhydrophobic surface from Cassie-Baxter state to Wenzel state, which accelerates the metallic corrosion. Herein, corrosion process of superhydrophobic coatings were investigated by in-situ growth of LDH lamellae with different platelet spacing and modification of stearic acid. The corrosion protection mechanism of the superhydrophobic coating divided into two stages: the well-known air film blocking effect and the hydrophobicity-depended barrier performance, which is a new focus. Through investigating the influences of the nano-structure on corrosion protection via experiments and simulation, a new mechanism on corrosion protection failure of superhydrophobic surfaces in atmospheric environment is proposed.

Achieving high accuracy of Co-Cr-Mo femoral head for improving tribological properties of hip joint prosthesis via a three-axial MFAF process

Rough surface and low precision roundness of femoral head can significantly affect tribological properties of hip joint prosthesis such as wear, von Mises stress, friction coefficient, and scratches, resulting in failure of hip joint prosthesis. In this work, firstly, an ultra-smooth surface with a high precision roundness was achieved for Co-Cr-Mo femoral heads via a three-axial Magnetic Field Assisted Finishing (MFAF) process. Secondly, the effects of a rough and smooth surface of Co-Cr-Mo femoral head on wear rate of acetabular cup were evaluated via a wear simulator test. Finally, the von Mises stresses of both femoral heads and acetabular cup were evaluated via ABAQUS finite element (FE) model. Using this process, surface roughness (Sa) and roundness (RONt) of femoral head were reduced from 0.330 to 0.032 μm and from 26.15 to 2.17 μm, respectively. A high accuracy of Co-Cr-Mo femoral head was achieved by reducing its surface roughness and roundness, which reduced the wear rate of the acetabular cup by more than 68 % compared to an unfinished femoral head. In addition, an ultra-smooth surface of femoral head dramatically reduced the von Mises stresses at the contact area of hip joint prosthesis. Results of this work demonstrate that a three-axial MFAF process is an effective method to successfully achieve high accuracy of Co-Cr-Mo femoral head with advantages of simultaneously improving tribological properties of hip joint prosthesis.

Excellent oxidation resistance of rapidly crystallizing Cr2AlC coatings at high temperatures: Effect of microstructure

Two kinds of Cr2AlC coatings with different microstructures were prepared by direct crystallization during oxidation at 1000 ℃ and conventional crystallization at 700 ℃ for 1 h for amorphous Cr-Al-C coatings prepared by magnetron sputtering, respectively. The effect of microstructure on the oxidation behavior of the coatings at 1000 ℃ was investigated. The grain boundary density and dislocation density of the Cr2AlC coatings crystallized directly during oxidation were much higher, which provided much more sites for heterogeneous nucleation of α-Al2O3 and fast diffusion paths for Al. Therefore, the coating formed complete pure α-Al2O3 scales earlier with better antioxidant properties. More importantly, the present work demonstrates feasibility and advantages of directly applying amorphous Cr-Al-C coatings at high temperatures without additional crystallization treatments, which simplifies preparation process of Cr2AlC coatings, facilitates their industrial applications, and provides a new method for rapid preparation of MAX-phase coatings.

Hydrophobic Coating of Vegetable-Tanned Leather with Dodecylamine

Vegetable-tanned leather exhibits a hydrophilic character due to the abundance of hydroxyl groups (-OH). In this study, the surface of vegetable-tanned leather was modified to become hydrophobic. The leather was coated using dodecylamine (DDA) through the padding method in the finishing process. The concentration of DDA varied from 1%, 2%, 3%, and 4% to identify the optimum concentration. The coating process was assisted by an activator, either acid or base, to improve the adhesion of DDA to leather. Uncoated vegetable-tanned leather was used as a control. The success of coating was identified using FT-IR and SEM-EDX analysis. The hydrophobicity of leather was conducted through a water resistance test. The success of coating is shown by the increase in their weight and thickness. Absorption bands of alkyl and amino groups of DDA are observed in FT-IR spectra around 1450 cm-1 and 3400 cm-1, respectively. SEM micrographs show that coated leathers have flatter surfaces as a consequence of DDA attachment on the leather surface. The water resistance test proves that the use of DDA can improve the leather hydrophobicity and enhance the water absorption time by up to 4 times. The optimum water absorption time is obtained when using 2% DDA.

Solidification evolution and corrosion performance of CoCrFeNiBx eutectic high entropy alloy coatings

CoCrFeNiBx (x = 0.15, 0.30, 0.45, 0.60, 0.75) eutectic high entropy alloy (EHEA) coatings, abbreviated as B0.15–B0.75, were prepared by laser cladding. The inevitability of solid-state phase transition in B0.75 coating has been verified from the perspective of enthalpy. The solidification and crystallization process and laws of the CoCrFeNiBx coatings were obtained by observing the phase and microstructure, combining the DSC testing and analysis. When the mole ratio of B atoms x ≤ 0.45, the FCC1 phase solidifies into dendrites, and the eutectic structure composed of the coupling of FCC1 and FCC2 lamellae forms between dendrites. As the content of B increases, the proportion of eutectic structure rises steadily while the dendrites refine and decrease. When x = 0.60, the B content reaches the eutectic point, forming the eutectic structure with a feathery appearance. When x = 0.75, a strip-shaped boride structure will also precipitate after the formation of the metastable eutectic structure. The B element can promote the formation of eutectic structures, thereby improving the microhardness of the CoCrFeNiBx coatings from 267.0 HV0.2 to 555.4 HV0.2. However, as the B content rises, the corrosion current density of the CoCrFeNiBx coating in 3.5 % NaCl solution decreases from 1.08E−07 A/cm2 to 8.92E−06 A/cm2. The corrosion mechanism changes from pitting corrosion to intergranular corrosion. The high-phase interfacial energy of the eutectic structure exacerbates the galvanic corrosion of the coatings.

Monitoring method and application of transition process with nonstationary conditions based on stability factor partitioning and RSFA

It is common for the working conditions to change with time in actual industrial processes. However, the transition modes of complex industrial processes under different working conditions often have various degrees of dynamic nonstationarity, which makes the traditional process monitoring model based on the stationarity assumption ineffective. In this paper, a Recursive Slow Feature Analysis method based on Stability Factor Partitioning (SFP-RSFA) is proposed for fine process monitoring of transition modes under dynamic nonstationarity characteristics. First, we calculate the stability factor according to the different stationarity characteristics of the production process variables. Then, K-means clustering is carried out according to the stability factor of each variable, and the stability factor of the cluster center is mapped to the interval [0,1] as the smoothing coefficient of the exponential weighted moving average (EWMA), which is applied to each data subblock respectively to highlight the steady-state and dynamic characteristics of the monitoring data subblock. In the online monitoring stage, the monitored data are fed into the subblock recursive slow feature analysis (RSFA) monitoring model. Finally, a comprehensive statistic method is proposed to integrate the subblock monitoring statistics. The Tennessee Eastman (TE) process and actual cement clinker production process were tested and compared with existing RPCA, RCA and RSFA methods. The effectiveness and superiority of the proposed method in the problem of nonstationary transition mode process monitoring are verified.