Grinding Process Research Articles

Active vibration control in robotic grinding using six-axis acceleration feedback

Industrial robots endure severe vibrations in the grinding process due to factors such as joint flexibility, low damping, and contact force fluctuations. Additionally, the motion control of the robot primarily relies on feedback signals from the motor-side encoders, while lacking motion state feedback from the load side. This exacerbates the robot vibrations, severely compromising the surface quality of the workpieces. To address this problem, an active damping control method for robotic grinding using six-axis acceleration feedback is proposed. This method realizes a simple, reliable, and efficient active vibration control without altering the robot body. A multi-sensor fusion Cartesian space six-axis accelerometer is designed and integrated into the robot end effector, achieving accurate feedback on the robot load side vibration state. The strategy of six-axis acceleration decoupling and principle of the vibration suppression with the acceleration feedback are explained. Compared with conventional sensing schemes, this reduces joint acceleration approximation errors and end vibrations. The robotic grinding experiments are carried out on aeronautic structural parts. Extensive case studies demonstrate that the proposed approach can effectively control the vibration caused by joint flexibility in the robot grinding process, and greatly improve the surface quality of workpieces. This method has great potential application in vibration suppression during robotic grinding and polishing.

Multiphysics simulations of uniaxial compression applied to various rock samples subject to microwave pretreatment

PurposeAmong the various applications involving the use of microwave energy, its growing utility within the mining industry is particularly noteworthy. Conventional grinding processes are often overburdened by energy inefficiencies that are directly related to machine wear, pollution and rising project costs. In this work, we numerically investigate the effects of microwave pretreatment through a series of compression tests as a means to help mitigate these energy inefficiencies.Design/methodology/approachWe investigate the effects of microwave pretreatment on various rock samples, as quantified by uniaxial compression tests. In particular, we assign sample heterogeneity based on a Gaussian statistical distribution and invoke a damage model for elemental tensile and compressive stresses based on the maximum tensile stress and the Mohr–Coulomb theories, respectively. We further couple the electromagnetic, thermal and solid displacement relations using finite element modeling.Findings(1) Increased power intensity during microwave pretreatment results in decreased axial compressive stress. (2) Leveraging statistics to induce variable compressive and tensile strength can greatly facilitate sample heterogeneity and prove necessary for damage modeling. (3) There exists a nonlinear trend to the reduction in smax with increasing power levels, implying an optimum energy output efficiency to create the maximum degradation-power cost relationship.Originality/valuePrevious research in this area has been largely limited to two-dimensional thermo-electric models. The onset of high-performance computing has allowed for the development of high-fidelity, three-dimensional models with coupled equations for electromagnetics, heat transfer and solid mechanics.

Grinding performance investigation of multidirectional CF/PEEK composites—A comparative with unidirectional CF/PEEK

AbstractTo distinguish the grinding performance of the multidirectional (MD) and unidirectional (UD) carbon fiber‐reinforced thermoplastic (CFRTP) composites, MD and UD carbon fiber‐reinforced poly‐etherether‐ketone (CF/PEEK) composites were employed in this study. Different ply stacking sequences and process parameters were set for grinding experiments. Subsequently, the surface morphologies and roughness were observed and measured. Experimental results indicated that the variations of grinding forces with grinding parameters of MD‐CF/PEEK and UD‐CF/PEEK were consistent. However, the heat transfer mechanism and the effects of grinding parameters on the maximum grinding temperatures were different between the two composites. The grinding forces and temperatures of MD‐CF/PEEK were slightly lower than UD‐CF/PEEK, and MD‐CF/PEEK reached better surface quality under the same parameters, indicating that the grinding performance of MD‐CF/PEEK was not the simple superposition of UD‐CF/PEEK. In addition, the chip formation and material removal mechanism of CF/PEEK were investigated. The grinding performance of MD‐CF/PEEK was primarily dependent on the θ elements of laminate while the grinding performance of UD‐CF/PEEK was closely related to the fiber orientation angles during grinding. This study established a more in‐depth understanding into the grinding performance of MD‐CF/PEEK and provided technical guidance for high‐quality grinding of CFRTP.Highlights The grinding performance of the multidirectional (MD) and unidirectional (UD) carbon fiber‐reinforced poly‐etherether‐ketone (CF/PEEK) is compared. The grinding forces and temperatures of MD‐CF/PEEK are slightly lower than that of UD‐CF/PEEK, and the MD‐CF/PEEK reach a better surface quality under the same grinding parameters. The grinding performance of MD‐CF/PEEK is primarily dependent on the θ elements of laminate, and the change of layering order is not a critical factor. The grinding performance of UD‐CF/PEEK is closely related to the fiber orientation angles during the grinding process. The surface quality of MD‐CFRTP can be effectively improved by reducing the grinding depth and feed speed, and increasing the grinding wheel speed.

IGZO thin films deposited by ultrasonic spray pyrolysis: effect of Zn precursor milling and In and Ga concentration

Codoped zinc oxide thin films with indium and gallium (IGZO) were deposited on soda-lime glass substrates by the ultrasonic chemical spray (USP) technique. The influence of the mechanical grinding process of Zn precursor (zinc acetate, AcZn) and the In and Ga concentrations was analyzed. The grinding process was carried out in a planetary ball mill, with a ball:/precursor ratio of 4:1, and a constant rotation speed of 300 RPM. The starting solutions were prepared at a molar concentration of 0.2 and variable In and Ga atomic concentration (1, 1.5, 2, 2.5 and 3 at%). The deposition conditions were kept constant, substrate temperature of 450 °C and deposition time of 7 min. Structural, morphological, optical, and electrical properties were analyzed. From the structural analysis a preferential orientation along the (101) plane for dominant In concentrated IGZO films was observed, whereas for dominant Ga concentrated was the (002) plane. The average optical transmission was in the range of 83–90%, confirming the high transparency of all the deposited films. The bandgap values, Eg, showed slight variations, from 3.43 to 3.53 eV. The best electrical properties were obtained in the IGZO films with an In:Ga ratio of 1.5:1 [IGZO(1.5:1)], evaluated by the figure of merit, 3.50 × 10–3 (Ω/□)−1, calculated for an optical transmission of 86% and a sheet resistance of 63 Ω/□. According to the obtained results, the IGZO thin films deposited by the USP technique, are potentially applicable in the field of optoelectronics, mainly as transparent electrode.

Optimization of adaptive and sustainable gold ore grinding processes for better environmental and land conditions in the small-scale gold mining sector in Indonesia

The artisanal and small-scale gold mining (ASGM) sector largely relies on mercury in gold processing, posing potential environmental contamination, health issues, and land degradation. In the villages of Tatelu and Talawaan, ASGM operations, guided by local knowledge and resources, have transitioned to using cyanide leaching for gold processing sustainably. These operations utilize andesitic stones from river deposits as grinding media in the grinding process. However, the cyanide leaching results were not optimal, with a gold recovery below 60%. This leaves significant amounts of gold in the waste, necessitating further processing and the incomplete treatment of free cyanide waste. The suboptimal gold recovery in cyanide leaching is attributed to the inadequate grain size liberation during grinding. This study optimized grinding by comparing andesitic stone grinding media with steel balls and rods. The findings indicate that to achieve a grain size of 75% passing 74 um, grinding with andesitic stones takes 4 hours, while steel rods and balls take 3 hours. For a grain size of 75% passing 44 um, grinding with andesitic stones, steel balls, and rods requires 6 hours. With more precise process parameters, locally available andesitic stones can be an effective grinding medium to optimize gold recovery. In line with optimizing gold recovery, this will enhance ASGM's revenue, encouraging the adoption of waste management practices to alleviate environmental impact, health risks, and land degradation. This aligns with the promotion of sustainable practices within the ASGM sector.

Physicochemical Characterization of Simplicia Sambiloto (Andrographis paniculata) Powder with Types and Concentrations of Reagents in the Formation of Zn-Chlorophyll Complexes

During the process of making sambiloto simplicial which involves heat, it can cause degradation of chlorophyll. Increasing the stability of chlorophyll can be done by forming Zn-chlorophyll complexes with metals which are be able to form complexes where more stable than Mg such as by using Zn. The aim of this research is to determine how the physical and chemical characteristics of the bitter simplicia powder produced are influenced by the type of reagent and the concentration of the reagent when heated in an oven. Simplicia bitter powder is made through a sorting, grinding and sieving process. Next, the zinc chloride and zinc acetate reagents were mixed with concentrations of 0, 200, 300, 400, and 500 ppm, and then dried. The results showed a real effect (p value <0.05) of the interaction between the types of ZnCl2 and Zn acetate reagents and the reagent concentration on color intensity, color stability, water content, ash content and chlorophyll content. The higher the concentration of ZnCl2 and Zn acetate, the higher the water content, ash content, chlorophyll content, L*, and -a*, while b* and ∆E decrease. At a concentration of 500 ppm ZnCl2 showed an increase in water, ash, chlorophyll, ∆E, L*, and a* content while b* decreased. Meanwhile, Zn acetate 500 ppm moisture content, ash content, chlorophyll content, L*, and ∆E decreased, while a* and b* increased. Sambiloto simplicia powder which has the highest chlorophyll content is Zn acetate 400 ppm, with characteristics of water content 6.81% ww, ash content 15.74% ww, total chlorophyll 397.97 mg/100 g ww, green color intensity (-a) -2.93, and ∆E 5.48.

Process Mineralogy of Lithium and Rubidium in the Diantan Polymetallic Mining Area, Tengchong, Southwest China

Highly differentiated granite often contains abundant key metal resources, such as lithium and rubidium. The Tengchong area of Yunnan hosts a large number of highly differentiated granites from the Cretaceous age. Among these, granite samples from the Diantan tin–lead–zinc polymetallic mining area exhibit Li contents exceeding 0.02% and Rb contents surpassing 0.1%. This suggests a promising potential for Li and Rb mineralization. However, the occurrence status and process mineralogical characteristics of Li and Rb remain unclear, directly impacting the assessment of the region’s comprehensive utilization potential for these key metals. This study focuses on representative granite samples from the Diantan mining area to conduct petrographic and process mineralogical research, examining single mineral chemical composition, physical properties, element occurrence state, and mineral embedding particle size. The results indicate that mica minerals primarily contain Li, while both feldspar and mica minerals are the main carriers of Rb. Zinnwaldite not only contains the highest Rb proportion among the samples but also plays a significant role in Li occurrence. Based on the dissociation characteristics, it is recommended to grind the material to a fineness of −0.075 mm, comprising 80% of the particles, before proceeding to the final flotation process. This would result in approximately 95% dissociation of the mica in the sample. Since mica is predominantly distributed between quartz and feldspar particles, with relatively low binding force, it facilitates mineral dissociation during the grinding process. Therefore, the actual beneficiation process may consider a moderately coarser grinding fineness based on the aforementioned findings.

Исследование гранулометрического состава измельченного продукта, полученого при измельчении доломита в центробежной мельнице вертикального типа

Introduction. Modern medium (10–200 microns) and fine (0.1–10.0 microns) powders have a high cost, which limits the scale of their production and use. This assumes the implementation the latest achievements in the field of creating new equipment that is not inferior in its technical characteristics to the best foreign models into industry. The use centrifugal mills of vertical type for grinding various raw materials has shown their high efficiency in obtaining materials in the range – 0.2–0.01 mm. Studies of these mills operation under various operating conditions made it possible to create a large data set on the dependence of the crushed material granulo-metric composition on the design features of the mills and technological parameters of the grinding process. The results of a previously study of the granulo-metric composition a finely dispersed crushed product integral distribution according to particle size classes less than 80 microns were presented. They were obtained in a Brookhaven BI-XDC X-ray analytical centrifuge by measuring particle sizes in natural sedimentation mode, when the centrifuge disk was stationary during the experiment. The studies of the particle size differential distribution of a finely dispersed crushed product according to particle size classes less than 80 microns, which have not been carried out to date are of particular interest. Purpose of the study. The differential distribution study of the finely dispersed granulo-metric product composition obtained by grinding lump dolomite in a centrifugal mills of vertical type under different operating modes. Materials and methods. To solve this problem, samples of crushed material were taken from grinding dolomite from the Bosninsky deposit (RNO-Alania) in a centrifugal mill of the vertical type MV-0.3 with a 300 mm rotor diameter with following technological modes of the grinding process: mill rotor speed n = 310; 360 min–1, height of the material column above the rotating rotor H = 180; 270 mm, test time – 6 hours. Selected samples with a size class of –0.08 mm were analyzed in an X-ray analytical centrifuge Brookhaven BI-XDC, designed to determine the particle size distribution in the range from 0.01 to 100 microns. The measurements were performed on a suspension prepared from a mixture of 0.5 g of the selected sample with a 20% solution of sucrose and distilled water. Samples with a size class of 0.08 mm were weighed on laboratory scales LV SP.005.048 RE. The resulting suspension was dispersed in an ultrasonic bath for 3–5 minutes. After dispersion, the suspension was poured into the analyzer disk. While stirring, the lower absorption baseline line of a homogeneous particle suspension was measured. The obtained data from the analysis of the fine fractions size of were processed by the centrifuge computer software and graphs of the differential distribution of particles were constructed for various technological modes of grinding dolomite in a centrifugal mill. During the processing of the experiments, minor bursts in the concentration of the crushed product were not taken into account. The results and discussion. For the first time, a differential analysis of the granulo-metric composition of finely dispersed material with a particle size of –0.08 mm, obtained by grinding lump dolomite in a centrifugal mill of the vertical type under different mill operating modes, was carried out. Under all investigated operating modes of the centrifugal mill, the main part of the fine fraction in the mill outlet was in the range from 1.197 to 4.643 μm, and in steady-state operation it varied from 1.310 to 4.601 μm. The range of fine particle sizes has maximum values when the height of the column of crushed material above the rotating mill rotor and the rotation speed of the mill rotor decrease, and minimum values are observed when the height of the column of crushed material above the rotating mill rotor increases and the rotation speed of the mill rotor increases. Resume. 1. The article presents the results of the granulo-metric composition differential distribution study of a finely dispersed product obtained by grinding lump dolomite in a centrifugal mill of the vertical type. 2. The conducted studies have shown that, despite the positive results in obtaining fine particles with a size of 0.001 microns (nanoparticles) by mechanical means, the industrial production of nano-materials when grinding lump mineral raw materials in a vertical centrifugal mill is not economically profitable due to the low specific productivity and high energy intensity of the grinding process. 3. The obtained research results can be useful in the design of centrifugal mills.

Research on control strategy of abrasive belt type rail grinding for corrugation repair process

The rail corrugation will lead to noise pollution and abnormal vibration in the railway operation process which greatly influences the safety, comfort, and stability of the train operation. However, although the advantages of abrasive belt rail grinding in repairing rail diseases have been verified, there is still no relative grinding control strategy for rail corrugation repair process due to its characteristics of regionality and no grinding benchmark. Therefore, this paper analyzed the difference between the grinding process of rail corrugation and ideal rail surface, and established material removal model for repairing of rail corrugation. By comparing the average valid value of moving wave amplitude and the improvement degree of rail corrugation, the most suitable grinding control strategies for repairing different types of corrugation diseases were obtained, which can further improve the grinding quality and efficiency of abrasive belt rail grinding in repairing rail corrugation.

Strategy of Charge Compensation for High-Performance Ni2+-Activated MgAl2O4 Spinel Near-Infrared Phosphor Synthesis via the Sol-Gel Combustion Method.

Near-infrared (NIR) phosphor conversion light-emitting diodes (pc-LEDs) have great application potential as NIR light sources in many fields such as food analysis, night vision illumination, and bioimaging for noninvasive medical diagnosis. In general, phosphors synthesized by a high-temperature solid-phase method have large particle sizes and have to be processed to fine powders by a grinding process, which may introduce surface defects and lower the luminous efficiency. Here, we report a sol-gel sintering method with ammonium nitrate and citric acid as the sacrificing agents to synthesize high purity, nanosized (less than 50 nm) Zr4+/Ni2+ codoped MgAl2O4 spinel NIR phosphors, in which MgAl2O4 spinel is the matrix, Ni2+ is the luminous center, and Zr4+ acts as the charge compensator. We systematically characterized the crystal structures and NIR luminescence properties of the Ni2+-doped MgAl2O4 and the Zr4+/Ni2+ codoped MgAl2O4. Under 390 nm light excitation, the emission spectrum of the Ni2+-doped MgAl2O4 phosphor covers 900-1600 nm, the half-peak width is 251 nm, and the peak position is located at 1230 nm. We demonstrated that by incorporating small amounts of Zr4+ as the charge compensator, the NIR emission intensity of the Zr4+/Ni2+ codoped MgAl2O4 nanosized phosphor was doubled over that of the Ni2+-doped MgAl2O4 phosphor. The optimal content of the charge compensator was 2 mol %. More importantly, the inclusion of Zr4+ led to a NIR phosphor with improved thermal stability in luminous properties, and the luminous intensity measured at 100 °C was 33.83% of that measured at room temperature (20 °C). This study demonstrates that NIR phosphor nanomaterials with high-purity and enhanced optical properties can be designed and synthesized through the charge compensation strategy by a sol-gel sintering method.

Simulating Dynamics of Feed Grain Vibration Grinder

The paper notes the feasibility of a vibration-based method for feed grain grinding. However, preference should be placed on dynamic machine configurations that enhance energy efficiency and increase the overall structural reliability. In this regard, it is worth considering the vibration grinder proposed in Patent RU 2688424C1. (Research purpose) The study aims to improve the technical capabilities of feed grain vibration grinders through the utilization of self-synchronization effects in vibration exciters and anti-resonance in working components. (Materials and methods) The authors developed a mathematical model for the dynamics of the working bodies in this type of a grain vibration grinder, taking into consideration the design of these bodies and their interaction with the technological environment. (Results and discussion) The findings show that effective execution of the technological process requires counter-rotating unbalance shafts and fine-tuning the working bodies to operate in an anti-resonance mode. The experiment confirms stable self-synchronization of vibration exciters in the anti-resonance mode of the working bodies, although the phasing of the unbalance shafts deviates slightly from the theoretical 180-degree mark, measuring between 168 and 170 degrees. This deviation does not have an adverse impact on the grinding process. As a result, the initial hypothesis combining the effects of self-synchronization in vibration exciters and anti-resonance in working bodies has received both theoretical and experimental confirmation. (Conclusions) It has been established that effective implementation of the technological process necessitates the counter-rotation of unbalance shafts, resulting in the self-synchronization of vibration exciters, and adjustment of the working bodies to an anti-resonance mode.

Urchins CuCo2S4/Carbon composites with abundant defects and hetero-interfaces for optimized impedance matching and broadened effective band width

This work adopts a composite strategy combining “large anisotropic structure” and “strong dielectric material”, which is a pioneer work reported on urchins CuCo2S4/C absorber. An environmentally friendly (eco-friendly) CuCo2S4/C composites were prepared through a facile route including an ion exchange method and a simple physical grinding process. The resultant CuCo2S4/C composites exhibit an urchins-like morphology with carbon nanoparticles anchored randomly on the tentacles of the urchins. The urchins CuCo2S4/C composites display an optimal reflection loss value of −44.2 dB at the thickness of 2.2 mm, and the effective bandwidth with RL < −10 dB reaches 7.12 GHz at a thickness of 2.4 mm. The outstanding electromagnetic (EM) wave absorption performance is mainly benefited from the synergistic effects between the anisotropic structure of CuCo2S4 and conductive carbon particles. By adjusting the component ratio during the grinding process, an optimized combination of conduction loss and polarization loss can be achieved, and the impedance matching level can be regularly controlled and improved while increasing the effective absorption bandwidth. These results indicate that the sea urchin CuCo2S4/C composite material designed in this work can serve as an ideal candidate for high-performance electromagnetic wave absorption and has certain reference significance for the development of more sulfide semiconductor based absorbing materials.

The robot grinding and polishing of additive aviation titanium alloy blades: a review

PurposeThe purpose of this review is to comprehensively consider the material properties and processing of additive titanium alloy and provide a new perspective for the robotic grinding and polishing of additive titanium alloy blades to ensure the surface integrity and machining accuracy of the blades.Design/methodology/approachAt present, robot grinding and polishing are mainstream processing methods in blade automatic processing. This review systematically summarizes the processing characteristics and processing methods of additive manufacturing (AM) titanium alloy blades. On the one hand, the unique manufacturing process and thermal effect of AM have created the unique processing characteristics of additive titanium alloy blades. On the other hand, the robot grinding and polishing process needs to incorporate the material removal model into the traditional processing flow according to the processing characteristics of the additive titanium alloy.FindingsRobot belt grinding can solve the processing problem of additive titanium alloy blades. The complex surface of the blade generates a robot grinding trajectory through trajectory planning. The trajectory planning of the robot profoundly affects the machining accuracy and surface quality of the blade. Subsequent research is needed to solve the problems of high machining accuracy of blade profiles, complex surface material removal models and uneven distribution of blade machining allowance. In the process parameters of the robot, the grinding parameters, trajectory planning and error compensation affect the surface quality of the blade through the material removal method, grinding force and grinding temperature. The machining accuracy of the blade surface is affected by robot vibration and stiffness.Originality/valueThis review systematically summarizes the processing characteristics and processing methods of aviation titanium alloy blades manufactured by AM. Combined with the material properties of additive titanium alloy, it provides a new idea for robot grinding and polishing of aviation titanium alloy blades manufactured by AM.

Prestressing method to inhibit crack initiation and expansion in a large-sized diamond film during polishing

A piece of diamond film (Ø 125 mm) was polished based on prefabricated stress. The diamond film was glued to a metal workpiece at high temperatures. The difference in the thermal expansion coefficients between the diamond film and the workpiece was exploited to prefabricate stress in the middle of the two materials. This prefabricated stress had a compressive effect on the diamond film, offset the stress generated in the grinding and polishing process, and prevented the diamond film from cracking. The feasibility of the prestressing method was verified by a combination of experiments and finite element simulations. The prestressing method was used to bond the diamond film to a 10 mm-thick brass fixture at 20, 50, 70, and 90 °C. It was found that when the temperature of the bonded diamond film reached 90 °C, the increase in the prefabricated stress was −410.71 MPa. The finite element simulation results were found to be consistent with the experimental data. The diamond film was cooled down to room temperature after bonding at high temperatures to simulate the prefabricated stress generation process. The diamond film with the prefabricated stress was again heated to the bonding temperature to simulate the stress change caused by the frictional heat generated during the polishing process. The stress of the bonded sample increased when it was cooled down to room temperature. The stress on the diamond surface became smaller during the polishing process, and the stress almost disappeared with the rise in bonding temperature, verifying the viability of the prestressing method.

Atomic-scale simulation of ultrasonic vibration-assisted polishing process for graphene/GaN-layered composites

In the realm of semiconductor materials, the integration of graphene (Gr) and gallium nitride (GaN) has emerged as a promising avenue for enhancing device performance. In this study, a Gr/GaN layered nanocomposite was constructed using molecular dynamics simulation and the LAMMPS code. Diamond abrasive was pressed into the composite at a speed of 50 m/s at 300 K, followed by ultrasonic vibration-assisted polishing on the (0001) plane along the [01‾10] direction. By rigorously exploring various factors such as number of Gr layers, vibration amplitudes, vibration frequencies and grinding speeds, the study elucidates the intricate mechanisms governing material removal and subsurface damage. Key findings reveal optimal processing conditions, including three layers of Gr, an amplitude of 5 Å, a vibration frequency of 80 GHz and a grinding speed of 100 m/s, which result in enhanced material removal rates and improved surface quality. Additionally, the insertion of Gr layers within the GaN matrix demonstrates a remarkable reduction in friction and wear rates, highlighting the potential for enhancing device reliability and performance. This comprehensive investigation not only advances our understanding of ultrasonic vibration-assisted grinding processes but also underscores the transformative impact of Gr/GaN composites in semiconductor device fabrication.

Methods for obtaining humate-containing fertilizers from brown coal

ABSTRACT The purpose of the study is to examine the main methods of obtaining fertilizers and optimizing processes. Using methods of analysis, comparison, and experimentation, three main approaches to obtaining fertilizers were identified: grinding and mixing with potassium hydroxide (KOH), ultrafine grinding with chemical additives, and a complex method for processing caustobioliths. Comparative analysis of the investigated methods allowed for identifying their advantages, disadvantages, and effectiveness. The key result was the ability to determine the most effective method for producing humate-containing fertilizers from brown coal, depending on specific production conditions and requirements. The results of the study showed that the ultrafine grinding process with chemical additions, such as urea and alkali metal hydroxides, showed promising potential for creating highly effective humate-containing fertilizers from brown coal, in addition to the comparative analysis. After thorough optimization, this technique showed improved fertilizer utilization and superior plant uptake, making it a strong contender for sustainable farming methods. Nevertheless, achieving optimal results requires detailed process parameter optimization. The study underscores the importance of using brown coal in humate-containing fertilizer production as an environmentally safe and sustainable approach. The results can contribute to further development and improvement of humate-containing fertilizer production methods, promoting sustainable agriculture and increased crop productivity.

Analysis of Raw Materials and Production Process of Broiler Feed Crumble Type B-BR 1 MGB

PT Japfa Comfeed Indonesia, Tbk is a company engaged in animal feed which provides various types, one of which is crumble. Crumble is a granular food processed by the process of grinding and crushing pellets. In addition to pellets, crumble is preferred and more suitable for poultry farms with mechanized feed bins. Crumble-shaped feed products are an activity that combines many existing production factors with the aim of producing a product, which is beneficial to consumers.

Grindability Evaluation of Ultrasonic Assisted Grinding of Silicon Nitride Ceramic Using Minimum Quantity Lubrication Based SiO2 Nanofluid

Minimum quantity Lubrication (MQL) is a sustainable lubrication system that is famous in many machining systems. It involve the spray of an infinitesimal amount of mist-like lubricants during machining processes. The MQL system is affirmed to exhibit an excellent machining performance, and it is highly economical. The nanofluids are understood to exhibit excellent lubricity and heat evacuation capability, compared to pure oil-based MQL system. Studies have shown that the surface quality and amount of energy expended in the grinding operations can be reduced considerably due to the positive effect of these nanofluids. This work presents an experimental study on the tribological performance of SiO2 nanofluid during grinding of Si3N4 ceramic. The effect different grinding modes and lubrication systems during the grinding operation was also analyzed. Different concentrations of the SiO2 nanofluid was manufactured using canola, corn and sunflower oils. The quantitative evaluation of the grinding process was done based on the amount of grinding forces, specific grinding energy, frictional coefficient, and surface integrity. It was found that the canola oil exhibits optimal lubrication performance compared to corn oil, sunflower oil, and traditional lubrication systems. Additionally, the introduction of ultrasonic vibrations with the SiO2 nanofluid in MQL system was found to reduce the specific grinding energy, normal grinding forces, tangential grinding forces, and surface roughness by 65%, 57%, 65%, and 18% respectively. Finally, regression analysis was used to obtain an optimum parameter combinations. The observations from this work will aid the smooth transition towards ecofriendly and sustainable machining of engineering ceramics.

Steam explosion pretreatment: Dramatic reduction in energy consumption for wheat bran grinding

Wheat bran has attracted attention for its high dietary fiber content with unique nutritional value. Grinding wheat bran into flour to produce whole wheat products effectively meets the surging demand for functional foods. Nonetheless, the grinding of high-tenacity wheat bran requires a huge amount of energy, which raises the costs of wheat bran flour. To reduce the energy consumption in wheat bran flour, we proposed a steam explosion pretreatment assisted wheat bran grinding process in this study. Steam explosion (0.5 MPa, 2 min) allows effective destruction of the wheat bran dense structure, reduces the mechanical properties of the wheat bran, and increases the yield and cell wall breakage rate of the wheat bran flour. The steam explosion pretreatment can reduce energy consumption by 57.6% in the wheat bran grinding process, which offers tremendous opportunities for making industrial production a success story. Besides, reconstituted whole wheat flour with the addition of steam-exploded wheat bran exhibited excellent processing properties. Overall, this work demonstrates that steam explosion pretreatment has a significant effect on wheat bran and drastically reduces energy consumption during wheat bran grinding, and steam-exploded wheat bran flour can upgrade the processability of reconstituted whole wheat flour, which holds tremendous application potential.

Process Optimization of Robotic Grinding to Guarantee Material Removal Accuracy and Surface Quality Simultaneously

Abstract Simultaneously guaranteeing material removal accuracy and surface quality of robotic grinding is crucial. However, existing studies of robotic grinding process optimization have mainly focused on a single indicator that solely considers contour error or surface roughness, while studies that simultaneously investigate the impact of contact force, spindle speed, feed rate, inclination angle, and path space on the material removal profile (MRP) and the surface roughness are lacking. This paper proposes a hybrid optimization method that considers dimensional accuracy and surface quality constraints. First, an MRP model that considers the coupling influence of the contact force, spindle speed, feed rate, and inclination angle is presented. Then, a surface roughness model that considers the inclination angle is established. Finally, the contact force, feed rate, inclination angle, and path space are simultaneously optimized to satisfy the hybrid constraints of MRP accuracy and surface roughness. The proposed method ensures maximum grinding efficiency while satisfying dimensional accuracy and surface quality constraints. The proposed method is verified on an industrial robotics grinding system with a pneumatic force-controlled actuator. The results show that the proposed method has higher profile accuracy and lower surface roughness than traditional methods.