Rolling Speed Research Articles

Data Mining for Quality Prediction in Software-as-A-Service Concept: A Case Study in Offset Printing Company

Purpose: This research aims to design a model of quality prediction system using data mining methods in the software-as-a-service (Saas) environment in order to facilitate manufacturers to be able to analyse process and product quality without software investment.
 Methodology/Approach: To develop the quality prediction model, this study utilized a data mining methodology to extract knowledge from historical data collected from the offset printing industry, focusing on manufacturing parameters. Four classification algorithms (Decision Tree, k-NN, Naive Bayes, Random Tree) were employed and compared to identify the most precise model specifically tailored for offset printing. Subsequently, the prediction model was integrated into a web-based system to enable quality prediction.
 Findings: This study demonstrates practicality of integrating quality prediction into the SaaS framework, specifically for offset printing. This integration is designed to predict how manufacturing control parameters, such as printing slope angle, engine temperature, paper size, ink density, and roller speed, relate to the occurrence of product defects such as crumpled paper and imprecise printing.
 Research Limitation/implication: Generalizability is constrained by its focus on the offset printing industry, and prediction accuracy relies on historical data, which can vary across manufacturing sectors, affecting model performance.
 Originality/Value of paper: This article presents the concept and practical implementation of utilizing data mining in a SaaS environment to enhance the quality of manufacturing, with a particular emphasis on the offset printing sector.

Preparation of Short Carbon Fiber/Polydimethylsiloxane Conductive Composites Based on Continuous Spatial‐Confining Network Assembly Technique

With the development of electronic devices, conductive composites are receiving more and more attention, the demand for electrically conductive composites (ECC) is also increasing. However, the existing preparation process does not allow for the continuous preparation of electrically conductive composites. Therefore, we report a continuous spatial‐confining network assembly (CSNA) technique method to achieve an efficient and controllable preparation of electrically conductive composites. Short carbon fiber (SCF) and polydimethylsiloxane (PDMS) are used as conductive fillers and polymer matrix to prepare conductive composites, and the filler content of the prepared composites is 6 wt%. The electrical conductivity of the PDMS/SCF conductive composite is 73.72 S m−1, when flexible roll with a Shore hardness of 12.5 A and a roll pressure of 126 N is used. The effect of increasing pressure, the higher the number of rolls and the roll speed on the electrical properties of the composite, is also investigated. To sum up, the PDMS/SCF composite prepared by this preparation method is expected to achieve continuous production and application in medical, biological, thermal management, etc.

Analytical and numerical study of hot rolling railway rail sections with the help of simulation and finite element software

Hot rolling of sections is one of the metal forming processes used to shape materials into profiles with a fixed cross-section, such as road rails. Iron is chosen for this process due to its repeatability. Despite the numerous equipment and high costs associated with it, the analysis of this process and its simulation can be highly desirable. In this process, the initial raw piece is passed through several rollers until the desired section's shape is created (1,2). The more passes are made, the greater the reduction in the cross-sectional area, and the tolerances increase. During rail rolling, several key factors play a crucial role, including the length of the workpiece, cross-section change, piece deviation, roller speed, and friction. This article focuses on investigating the effective parameters in this process using simulation software. For the rolling analysis, we use an isothermal and rigid model of rollers, considering the heat transfer between the rollers and the rail during the shaping process. The analysis is performed using thermal stress solutions in Abaqus/explicit. Additionally, the workpiece may deviate due to the asymmetry of the top and bottom shapes. Hence, we examine the effects of the friction coefficient between the part and the rollers on rail deflection, stress values, strain, and rolling force. The results indicate that the maximum stress on the rail's surface occurs below the points of contact with the rollers, leading to a higher percentage reduction.

Investigation on roller-type ultrasonic assisted magnetorheological finishing for biomedical small and complex surface of titanium alloy

Biomedical small workpieces made of titanium alloys are widely used in orthopedic implants. However, the poor abrasive resistance and the complex shape of the parts with small size could seriously reduce its finishing quality and efficiency. In this study, a roller-type ultrasonic assisted magnetorheological finishing (R-UMRF) for biomedical small and complex surface of titanium alloy was proposed. The R-UMRF principle was illustrated in detail. Then, the magnetic circuits of R-UMRF with three-pole electromagnet excitation device was designed and mathematical expressions of magnetic flux density in the MR fluid polishing region was further established. Moreover, simulation analysis of the designed magnetic circuit was performed as well. An experimental prototype was fabricated and tested to the feasibility of the developed MR polishing fluid and R-UMRF device. The results showed that the surface roughness decreases with the increase in spindle speed and roller speed, however, it first decreases and then increases with the increase in ultrasonic amplitude and the applied current. In addition, the surface roughness change rate increases with the increase in spindle speed and roller speed, however, it first increases and then decreases with the increase in ultrasonic amplitude and the applied current. The optimized process parameters for the titanium alloy screws are the MR polishing fluid of MRPF-2, the spindle speed of 240 r/min, the roller speed of 110 r/min, ultrasonic amplitude of 10 µm, and applied current of 4 A. The surface roughness Ra of 0.089 µm can be obtained after 140 min finishing under the optimized parameters. R-UMRF is an adaptable and efficient method for finishing small and complex surface of titanium alloy.

Copper sulfides agglomeration using a novel lab-scale granulator: Integrated evaluation of bonding, leaching and mechanical behavior

The ore agglomerations could ameliorate intra-particle pore network, homogenize flow paths, and improve leaching efficiency of heap leaching. This paper innovatively develops a novel ore granulator with adjustable inclined angle and rolling speed. To comprehensively evaluate granulation procedure, the effects of physical (crushed feeds particle size distribution, rolling speed, inclined angle), chemical (binder type, curing time) and biological factors (bacterial concentration) on bonding performance of crushed feeds are analyzed. The objective of this paper is to obtain the optimal granulation conditions by studying the influence of various factors on the bonding ability, strength, and stability of granulated ores, in order to improve the pore structure of the heap leaching system, and increase the leaching rate of the ore. The results show that well-shaped agglomeration (WAs) does improve minerals leaching efficiency, and the uniaxial compressive strength of WAs is positively related to curing time, binder concentration, inclined angle, and rolling speed. The excessive lower or higher rolling speed is not suitable to get a higher extraction rate due to undesirable disintegration or compaction. The higher concentration (0.5–10 %) sulfuric acid solution could obviously increase WAs strength from 32.6 KPa to 48.3 KPa. The organic binders such as polyacrylamide are benefit for powders bonding and increase the compressive strength, but does not good for the desirable leaching reaction rate. The bacterial pre-adding has no significant positive influence on bonding and leaching efficiency. Relied on the 3D response surface, the preferred preparing condition is: 78.9 rpm rolling speed, 30° inclined angle, 7-days curing time and 9.3 % H2SO4 solution. Future studies should focus on exploring the intrinsic correlation between the various factors and evaluating the granulating and leaching effects from the perspective of chemical detection and leaching bacteria.

A Multi-Parameter-Coupled Mixed Lubrication Model for Rolling Interface Analysis: An Investigation on Interfacial Oil Pressure and Oil Film Thickness

Utilizing the average Reynolds equation, lubrication friction theory, metal rolling deformation theory, and temperature energy theory, a multi-parameter-coupling mixed lubrication model considering the influence of surface roughness with Gaussian distribution characteristics under rolling conditions was established. The results show that the stress distribution of the lubricating oil at the rolling interface conforms to the typical characteristics of line contact stress distribution. The oil film pressure does not increase significantly with the increase in the reduction ratio. A second peak pressure appears before the outlet. The second peak pressure reaches its maximum when ε = 0.2. The rolling speed has little effect on oil film pressure, but greatly affects oil film thickness. The influence of rolling speed mainly occurs in the outlet zone and at the second peak pressure location. The oil film thickness increases with rolling speed. During rolling, the temperature rise in the rolls exhibits two peak values. The first peak appears near the neutral point, and the second peak appears near the outlet, which is also where the second peak pressure is located. The influence of temperature will reduce the peak stress on the rolls. The overall stress on the rolls will also decrease.

Enhanced mechanical properties of AZ91 magnesium alloy by asynchronously large-strain high-efficiency rolling with bimodal grain structure

The study describes large strain high-speed asynchronous rolling process to process AZ91 magnesium alloy sheets with an overall thickness reduction of 84 % via two-pass rolling at 350 °C. Rolling speed ratios of 1.0, 1.1, 1.2, and 1.3 were used to obtain bimodal grain structure with different organizational states. Microstructural analysis unraveled that the formation of the bimodal structure was a consequence of combined effect of precipitation-strengthening and the Zener pinning effect. The R3 exhibiting an asynchronous ratio of 1.2 exhibited an optimized bimodal grain structure characterized by smaller recrystallized grains and a more homogeneous distribution. This phenomenon underscored the beneficial impact on enhancing strength and alleviating the anisotropic behavior.

Influence of rolling speed on fatigue crack initiation and growth of wheel steel under dry-wet rolling/sliding contact

In order to examine the effect of rolling speed on rolling contact fatigue (RCF) of wheel steel, dry-wet rolling/sliding tests were carried out at varied rolling speeds. Wear loss, friction coefficient, crack morphology, and crack size distribution of test wheel discs were analyzed. Finite element (FE) analysis was subsequently performed to evaluate the RCF crack growth according to the max ΔKeq criterion. By combining the findings from both experimental and FE analyses, potential influences of rolling speed on RCF crack initiation and growth were postulated. It was discovered that the crack initiation is governed by the ratcheting mechanism under dry condition. As the rolling speed increases, the initiated crack size first increases and then decreases, probably due to the concurrent rising of friction coefficient and yield strength. Furthermore, the predicted crack growth paths using FE model with and without considering the trapped fluid are consistent with test results at lower and higher rolling speeds, respectively. The driving force of crack growth in depth and branching direction decreases with an increase in rolling speed, probably owning to the reducing hydrostatic pressure in the crack cavity induced by the increasing air volume. This ultimately results in smaller crack size and reduced wear loss under wet condition.

Comprehensive evaluation of spray arrangement strategies for spray-local exhaust ventilation

A well-designed spray system, which is located near the source of high-temperature smoke, can improve the capture efficiency of traditional local exhaust ventilation (LEV). However, there is currently no comprehensive evaluation index that clearly reflects the performance of spray-local exhaust ventilation (SLEV), making it challenging to optimize the spray arrangement. The two-phase flow fields in the SLEV and LEV were compared to evaluate the impact of spray on smoke control. The effects of spray arrangement parameters, such as spray position, spacing, initial droplet size, and angle, on the performance of the SLEV system were further evaluated using current evaluation indicators. Based on this, we developed a comprehensive evaluation model for SLEV using the AHP-entropy combination weighting method. The results revealed that the decrease in smoke control with an increase in rolling speed is primarily caused by a reduction in spray control in the central region of the smoke. When the spray flow rate is 0.0028 kg/s and the velocity is 30 m/s, the primary factor that improves ventilation performance is the downward drag force exerted by the spray on smoke, rather than the cooling effect. The comprehensive model was developed using weights of 0.45, 0.34, and 0.21 for the three evaluation indicators: capture efficiency, high-quality concentration field ratio, and spatial droplet size. The model showed good reliability based on the results of the smoke concentration analysis. The results of this study are expected to guide the design, implementation, and evaluation of SLEV systems.

Design and experiment of brush-roller ginkgo leaf picker for the dwarf dense planting mode

At present, ginkgo leave are still picked manually. A brush roller ginkgo leaf picker has been designed to improve harvesting efficiency and reduce losses caused by manual failure to pick leaves in time under large-scale planting areas. The ginkgo leaf picker is mainly composed of crawler chassis, gantry frame, brush roller picking parts, and collecting box. The kinematics of the brush roller is analyzed for the picking omission situation. An experimental platform for picking ginkgo biloba leaves was established. Three parameters, namely roller speed, moving speed, and roller inclination, were selected for optimization. Then the maximum net harvest rate and the minimum damage rate were achieved. The orthogonal test showed that when the roller speed was 130 rev/min, the moving speed was 0.25 m/s, and the roller inclination was 32°, the picking effect was the best, the net harvest rate was 93.32%, the damage rate was 1.42%, and the damage degree of the trunks was slight. The experiment proved that the brush-roller ginkgo leaf picker has a good picking effect, which can provide a reference for the optimization design of ginkgo leaf harvesting machinery under the dwarf dense planting mode.

A Study on the Analysis of the Ground Compaction Effect According to the Roller Operation Method through CMV Analysis Using IC Rollers

In road construction, the compaction process using vibratory rollers is essential to increase the ground stiffness in earthworks. There need to be clear standards regarding the operation of compaction rollers during compaction work. Various simple quality inspection techniques have been developed to check the stiffness of the ground, but plate load test and field density test are the most commonly used test methods to evaluate the degree of compaction during road construction. However, both inspection methods could be more efficient, as they cannot be performed in all sections due to time and cost. Additionally, in compaction work today, the worker will individually judge the number of compactions, thickness, speed, vibration etc. based on his or her own experience. This means that the quality of compaction varies depending on the worker. In this study, quality inspection results for all sections were obtained using an intelligent quality control system that employs an IC roller, a technology that is now commercially available. The effect of the operating conditions of the vibrating roller (roller compaction direction, compaction roller speed, and compaction roller vibration method) on the compaction quality was analyzed using the intelligent quality control value. Through our highway construction site tests, it was found that the speed of the compaction roller and the vibration method of the compaction roller affected the degree of compaction, but the direction of compaction did not. Therefore, if the compaction work is performed by adjusting the driving speed and vibration method of the vibrating roller according to the ground conditions, repetitive compaction work can be reduced, thereby reducing construction costs and lowering work time, which will achieve an improved work efficiency.

Effect of ultrasonic surface rolling process on the microstructure and corrosion behavior of zirconium alloy in high-temperature water condition

Ultrasonic surface rolling processing (USRP) was carried out at zirconium (Zr) alloy with different rolling speeds to prepare gradient nanostructured layers, and the corrosion behavior of USRP treated Zr alloy was studied under 360 °C/18.6 MPa water condition. The surface morphology, microstructure, phase composition, and element distribution of USRP treated Zr alloy after corrosion was investigated. Results show that the oxide layer on Zr alloy comprises of t-ZrO2, m-ZrO2, and metal Zr. The thickness of oxide layer Zr alloy is reduced after USRP treatment, indicating that the gradient nanostructure can effectively improve corrosion resistance. This process is attributed to that the gradient nanostructure layer is helpful for the nucleation of equiaxed t-ZrO2 at the oxide/metal (O/M) interface with small grain size. The high compressive stress induced by USRP treatment is beneficial for the maintenance of t-ZrO2 phase and inhabiting the phase transformation from t-ZrO2 to m-ZrO2, which reduces the micro-cracks and defects due to volume expansion. The oxide layer on USRP treated Zr alloy with high content of t-ZrO2 phase presents a dense structure and prevents oxygen anions from diffusing to Zr alloy.

Influence of friction-lubrication characteristics varying with rolling speed on instability of chatter and slip in cold tandem rolling process

Influence of friction-lubrication characteristics varying with rolling speed on instability of chatter and slip in cold tandem rolling process

Ultrasonic measurement of roller revolution speed for high-speed rolling bearing

The sliding state of the bearing rollers can be identified by measuring the roller revolution speed. At present, the roller revolution speed is mainly approximated by the average speed of the cage, which can be obtained by optical and electric methods. However, there are some bottlenecks in the practical application of these methods. In this study, a non-destructive ultrasonic technique is proposed to measure the high-speed rolling bearings' roller revolution speed. In order to reduce the impact of time-domain noise on the ultrasonic echo pulse signal, autocorrelation analysis and the FFT transform are introduced. The passing frequency of a roller can be more accurately calculated by using the CZT (linear frequency modulation Z transform) spectrum thinning algorithm. This ultrasonic approach's validity is confirmed when compared to the conventional optical method at low speed. Then, in accordance with the theoretical models, the roller slippage at high speed is observed by directly measuring the speed of the roller revolution.

Effect of Roll Load on Microstructure of Roll Cast Al-10%Mg Strip

The effect of roll load on the microstructure of an Al-10%Mg strip cast using a vertcal-type high-speed twin-roll caster was investigated using roll stop and etching with Weck’s reagent. Roll stop was adopted to investigate the transformation of the microstructute near the roll bite. Weck’s reagent was used to visually determine the of the Mg solid-solution content. The roll load was 2, 88, or 420 N/mm and the roll speed was 30 m/min. A band zone formed at the center of the thickness direction for all roll loads. The Mg solid-solution content in the αAl in the band zone obtained at a roll load of 2 N/mm was greater than that obtained at roll loads of 88 and 420 N/mm. Recrystalization migh occur in the band zone of the strip at a roll load of 2 N/mm. The Mg solid-solution content in αAl near the surface was greater than that inside the strip in the thickness direction. The Mg solid-solution content in αAl near surface obtained at a roll load of 2 N/mm was greater than that obtained at roll loads of 88 and 420 N/mm.

Effects of Dry Granulation Operating Parameters on Forming Quality

To address the issues of the existing dry granulation process, which mostly relies on manual adjustments based on empirical experience and lacks the analysis of theoretical data, a simplified model of tablet pressing based on a modified Drucker–Prager Cap (DPC) material constitutive model was proposed to simulate and analyze the forming process of tablets, and study the impacts of the feeding speed, roller speed, friction coefficient and roller clearance on the density distribution of the pressed tablets via ABAQUS. The results show that the roller speed significantly impacts the density of tablets, and a lower roller speed and a higher friction coefficient are beneficial to the formation of tablets. As the roller clearance decreases, the average density at the clearance increases, and the unevenness of the lateral density distribution of the tablets increases, showing a distribution trend of larger density at the center and smaller density on both sides.

Recrystallization and Anisotropy of AZ31 Magnesium Alloy by Asynchronous Rolling

In this study, the microstructure and mechanical properties of AZ31 magnesium alloy were investigated through asynchronous rolling. The results demonstrate that the rolled sample exhibits a refined grain structure with a significant presence of continuous dynamic recrystallization. Notably, as the roll speed ratio increases, the grain refinement becomes more apparent. For the sample with a roll speed ratio of 1.3, the tensile strength in the rolling direction (RD) reaches 273 MPa, while the elongation measures 20.2%. Similarly, in the transverse direction (TD), the tensile strength reaches 282 MPa, accompanied by an elongation of 18.9%. These values indicate a substantial improvement in elongation compared to conventional rolling processes. The enhanced elongation can be attributed to two primary factors. Firstly, recrystallization contributes to a grain refinement recrystallization ratio of 86%, promoting improved mechanical properties. Secondly, the recrystallized grains induce a favorable Schmidt factor, further supporting elongation. Overall, the findings of this research highlight the benefits of asynchronous rolling in refining the microstructure and enhancing the mechanical properties of AZ31 magnesium alloy.

Machine learning approach for the prediction of mixed lubrication parameters for different surface topographies of non-conformal rough contacts

PurposeThis study aims to use a machine learning (ML) model for the prediction of traction coefficient and asperity load ratio for different surface topographies of non-conformal rough contacts.Design/methodology/approachThe input data set for the ML model is generated using a mixed-lubrication model. Surface topography parameters (skewness, kurtosis and pattern ratio), rolling speed and hardness are used as input features in the multi-layer perceptron (MLP) model. The hyperparameter tuning and fivefold cross-validation are also performed to minimize the overfitting.FindingsFrom the results, it is shown that the MLP model shows excellent accuracy (R2 > 90%) on the test data set for making the prediction of mixed lubrication parameters. It is also observed that engineered rough surfaces with high negative skewness, low kurtosis and isotropic surface patterns exhibit a significant low traction coefficient. It is also concluded that the MLP model gives better accuracy in comparison to the random forest regression model based on the training and testing data sets.Originality/valueMixed lubrication parameters are predicted by developing a regression-based MLP model. The machine learning model is trained using several topography parameters, which are vital in the mixed-EHL regime because of the lack of regression-fit expressions in previous works. The accuracy of MLP with random forest models is also compared.

An Experimental Investigation into Roughness Transfer in Asymmetrical Rolling of Steel Strips

This study investigated the effect of rolling parameters such as speed, thickness reduction, roll surface roughness, material thickness, surface condition (dry or lubricated), and rolling force on the roughening characterization in asymmetrical rolling. The surface roughness of the samples subjected to rolling tests was measured. The roughness values' average and standard deviation were found, and 3-D scanning images were acquired. Lubricated texturing experiments revealed that lubrication reduced roughness transfer. It was found that the introduction of roughness on the material surface decreased as the rolling speed increased. On the other hand, a higher speed increases the rolling force, which increases the surface roughness. The effect of speed on the standard deviation varies in direct proportion. Furthermore, lubricated rolling produced a more homogenous roughness distribution at higher speeds, while dry rolling produced homogeneous roughness at lower speeds. It was revealed that the rolling force is higher with thicker materials. While the roll roughness did not affect the rolling force using thicker material much, this effect was more pronounced in the very rough roll using thinner material. The standard deviation was lower in smaller reduction ratios using rough and very rough rolls. According to the results, although asymmetrical rolling has some advantages compared to conventional rolling, it was concluded that it is not a suitable method for roughening steel strips.

The effect of medical biodegradable magnesium alloy in vivo degradation and bone response in a rat femur model with long-term fixation.

It is of great significance to understand the effect of the different corrosion behaviors of magnesium (Mg) alloys manufactured using different casting methods and implanted with different methods on the long-term implantation to expand the application of Mg-based biomedical implants. The effects of four different casting and rolling speeds on the microstructure of an Mg-rare earth (Mg-Re) alloy were analyzed using electron backscatter diffraction (EBSD). Four Mg alloys were obtained using vertical two-roll casting (TRC) at 10m/min, 16m/min, 24m/min, and 30m/min, and their microstructure, corrosion behavior and bone reaction in vivo were studied. The corrosion resistance of the alloy increases with an increase in casting speed and finer grain size of the cast-rolled parts. The Mg-Re alloys with TRC-10m/min and TRC-30m/min were selected for animal experiments. The two Mg alloys were made into metal rods and inserted into the rat femur to simulate the effect of Mg-Re on femoral healing under an injury condition. The rods were implanted for a long time to judge the effects of the Mg-Re alloy on the body. The TRC-30m/min implants obtained highly mature new bone tissue in the case of bone injury. The in vivo experiments showed that the corrosion resistance of the TRC-30m/min implant was better than that of the TRC-10m/min implant. After 32 weeks of implantation, there were no pathological changes in the liver, heart, or kidney of rats in the TRC-30m/min group, and the cell structure was normal.