Rolling Pressure Research Articles

Modeling and simulation of the gear micro-pitting formation mechanism for surface roughness

A Micro-pitting damage is an early failure form of gear contact. Exploring its damage mechanism is very important to gear design, operation and maintenance. Considering the contact pressure distribution, sliding speed, rolling speed, film thickness and shear stress along the contact line, this paper takes into account the effect of the peak number of Gaussian surface roughness, and uses rheological methods to affect the crack initiation The number of minimum roughness peaks is calculated to simulate the crack initiation process, and a crack criterion method to predict the dangerous area of crack initiation is proposed. Then, considering the effect of accumulated stress, the topography of the contact surface gradually changes from a Gaussian rough surface to a non-Gaussian rough surface. Thus, after the crack initiation, this paper uses a non-Gaussian rough surface to further simulate the crack propagation process. The simulation results show that when the skewness of the non- Gaussian rough surface is constant, the crack propagation rate will increase with the increase in number of loads; when the skewness increases, the crack propagation rate will decrease.This paper first analyzes the advantages and disadvantages of the existing micro-pitting crack initiation and propagation model, then modifies the crack initiation criterion based on the number of Gaussian surface roughness peaks, and simulates the crack propagation with non-Gaussian roughness. Finally, an example is used to simulate and analyze the established model.

Characterization of Base Oil Effects on Aged Asphalt Binders Considering Bicycle Road.

Demand for various bicycles and sharing systems has constantly been growing worldwide as they improve the quality of life and promote eco-friendly transportation. Accordingly, it is inevitable that bicycle roads should be expanded. As bicycle roads have a relatively lower load applied than automobile roads, adopting a design method that uses a high reclaimed asphalt pavement (RAP) content can be beneficial. However, much uncertainty still exists about the relation between the mixing method and application in field sites, without appropriately considering the quality control of the rejuvenator. Therefore, this study aims to demonstrate the effect of base oil as a rejuvenator on aged binders, considering the use of a high RAP content for bicycle roads. To prepare the aged binder, a rolling thin-film oven (RTFO) and pressure aging vessel (PAV) were used to imitate the life cycle of asphalt pavement from production to service life, and then three contents of aged binder (0%, 50%, and 100%) were added and mixed with fresh PG 64-22 base binder. Finally, each type of prepared aged asphalt binder was blended with three different base oil contents (0%, 5%, and 10%). The results indicated that (1) the addition of base oil effectively decreased the viscosity of aged binders, (2) aged binders containing base oil showed less G*/sin δ compared to originally aged binders, and (3) the application of base oil improves the cracking properties of the aged binder by decreasing stiffness. In conclusion, the most striking observation from the data analysis from the Superpave test and statistical results was the effect of reducing the asphaltene portion based on the use of base oil in the aged binder. Therefore, using base oil in RAP can enable the application of a high RAP content to the bicycle road.

Mesta (Hibiscus sabdariffa) and polylactic acid thermally bonded fabric for sustainable shopping bags: modeling and optimization of functional properties

A thermally bonded biodegradable fabric has been developed using mesta and polylactic acid fibers. The central composite rotatable design has been adapted to understand the effects of the independent variables, that is polylactic acid content, roller temperature and roller pressure on useful functional properties such as bursting strength, bending load, tensile stress relaxation, tensile creep, rate of absorption, absorption capacity, porosity, abrasion resistance, and surface friction. Considering the linear, quadratic, and two-way interactive effects of independent variables, the second-order polynomial has been suggested for each property which proves good association except for absorption capacity and abrasion resistance. The effect of independent parameters has been studied and optimized from contour diagrams. The optimized process parameters for 140 g/m2 fabric are polylactic acid content 30%, mesta content 70%, roller temperature 170°C, and roller pressure 150 N/cm2, which can be used successfully as a shopping bag. The shopping bag was prepared from developed fabric. Its performance test shows no deformation for up to 14 days in the hanging test, resistance up to 10 wetting-drying cycles proves reusability, it sustains up to four drops, and has a slight strength loss in 30 days of atmospheric exposure.

Aging Potential and its Impact on the Bonding Strength of Rubberized RAP Asphalt Binder

Rejuvenating the reclaimed asphalt binder using crumb rubber-modified binder is a sustainable paving technology that has the advantage of using waste to recycle another waste material. As binder durability is crucial in evaluating the recyclability of reclaimed asphalt using crumb rubber-modified binder, this study investigates the binder potential for aging and the impact of aging on binder bond strength. Thirty binders with different crumb rubber and reclaimed asphalt dosages were aged by rolling thin oven and pressure aging vessel and tested by Fourier-transformed infrared spectroscopy and pull-off tests. The results reveal that binder aging and reclaimed binder addition strengthen the bonding strength and elevate the carbonyl intensity, which is the keen factor responsible for bonding enhancement. However, incorporating reclaimed binders attenuates the binder aging potential and limits the bonding enhancement after aging. Crumb rubber interacts with the asphalt binder and improves the bonding strength accordingly. However, the crumb rubber interaction with the binder significantly affects the aging potential of the binder, which increases with crumb rubber disintegration and decreases with rubber swelling. As rubber swelling is the dominating interaction mechanism, the crumb rubber modification mostly undermines the bonding enhancement after aging.

Specific pressure under roller squeezing of leather

The influence of factors on the width of the roller contact and the specific pressure under roller pressing of leather is analyzed in the article. As a result of experimental studies, the dependences of the width of the contact area and specific pressure on the intensity of the load, velocity, and diameter of the rollers were determined. It was revealed that the parameter of the technological specific pressure on the hide in the contact zone increases with an increase in the intensity of the load, the speed of rolls, the width of the contact area, and a decrease in the radius of rolls. An analytical dependence of the residual moisture content of leather on the specific pressure was determined. It was established that with an increase in specific pressure, the residual moisture content of leather decreases and asymptotically approaches a certain value of the function.

Flow control in paper-based microfluidic channel by using hydrophobic tape barrier on the paper surface

Paper-based microfluidics offers a simple, cost-effective, and versatile platform for fluid manipulation and analysis. Despite significant advancements in paper fluidics, the flow control in paper channel remains a challenging task. In this regard, we have developed a flow delay channel in paper using rectangular tape patterns on the paper surface. We have investigated the effect of hydrophobic tape barriers with varying widths. The designing and cutting of the hydrophobic tape and paper channel was performed by CO2 laser machine using CorelDraw software. Once cut, the tape barriers were attached to the paper surface and then passed through the roller press machine for proper adhesion of tape pattern onto the paper’s surface. From experiments, we observed that by increasing the width of tape, the delay also increased. The hydrophobic tape on the paper surface caused resistance to the flowing fluid. Due to this surface resistance, flow velocity reduced, and the time delay increased. We believe that our novel approach will provide an alternative method of flow control for paper-based microfluidic devices and can be utilized in various food quality sensors and lateral flow devices.

The effect of roller pressure and feed rate on hides squeezing

The article presents the results of experimental studies of the process of extracting excess liquid from a water-saturated hide. The experiments were conducted in two options: using a rigid base plate and a cermet base plate for the feed mechanism of the roller machine. In the study, samples of a wet hide on rigid and cermet base plates were pulled between rotating squeezing rollers using conveyor chains. Mathematical dependences of the amount of liquid removed from a wet hide on its feed rate and the pressure of the squeezing rollers were obtained for two special options. The experimental results showed a significant increase in the efficiency of the squeezing process of a wet hide due to the use of a cermet base plate in comparison with a rigid base plate.

Multiple response optimization of sizing machine settings and sized yarn tensile properties using advanced method of experimental design

On a loom, the warp yarns experience exceptionally high mechanical stresses and strains, as well as significant abrasion from friction. As a result, significant yarn breakages cause loom stoppages and, hence, production and quality interruptions. To mitigate this problem, the warp yarns should be treated with a thin, strong film of an appropriate adhesive. The aim of this study is therefore, to investigate the effect of sizing machine parameters on tensile properties of the yarn and to optimize the sized yarn tensile properties. Design expert 11 software with Box-Behnken design has been employed to design the research, analyze the results of experiments, and optimize the responses. In this research, three factors, each at three levels (wet zone yarn tension (A) (340, 380, and 420 N), squeezing roller pressure (B) (13, 15, and 17 N), and sizing machine speed (C) (30, 49, and 68 m/min), as well as three response variables (gain strength, loss elongation, and stretch), are considered. 15 samples of sized yarn have been produced with various combinations of the given factors, and the values of the response variables are measured for each sample. It has been observed that wet zone yarn tension and squeezing roller pressure have a significant effect on gain strength, stretch, and loss elongation. According to the regression analysis, gain strength has a negative relationship with wet zone yarn tension and a positive relationship with squeezing roller pressure. In the other case, both wet-zone yarn tension and squeezing roller pressure have a positive and significant effect on loss elongation and yarn stretch. At 340 N wet zone yarn tension, 13 N squeezing roller pressure, and 51 m/min sizing machine speed, the optimum values of gain strength (32.7 cN/tex), loss elongation (18.5%), and stretch (1.4%) were obtained. The methodologies employed in this study revealed the empirical relationship between the factors and the responses, the interaction effects of the factors on the responses, and multiple response optimizations. The optimized result of this study can be applied to the warp yarn sizing and can improve the tensile properties of the yarn and the loom’s efficiency significantly.

Formation mechanism of surface upwarping and black line defects on low carbon hot rolled plate

To improve the surface quality of low-carbon hot-rolled steel plates, the upwarping and black line defects were investigated by means of XRF (X-ray diffractometer), OM (optical microscopy), SEM (scanning electron microscopy) and EBSD (electron back scatter diffraction). The results showed that the micro area compositions under surface upwarping and black line defects were mainly made of secondary oxide particles, steelmaking slag and mould flux respectively. According to the metallographic structure, inclusion compositions and grains texture analysis, it could be concluded that surface defects on hot rolled plates were attributed to the entrapment of ladle slag or mould flux, gas bubbles, micro-cracks of casting slab in the steelmaking process, rolled-in scale and unreasonable sizing press rolling parameters during the rolling process, and the position and formation process of typical surface defects on hot rolled plates were discussed in detail. Finally, it concluded that the slag entrapment and solidification hook should be controlled during continuous casting.

Проблема оптимізації лабораторного ущільнення асфальтобетонних сумішей

The problem of ensuring the durability and operation of asphalt concrete layers of non-rigid road surfaces is closely related to the quality of the materials used, their composition and installation technology. The latter includes two defining stages: moving mixtures and their compaction. At the same time, the prediction of the properties of asphalt concrete should be carried out based on the results of laboratory tests, in the process of which the road, climatic and transport conditions of operation of one or another layer are taken into account. Reliable prediction can be ensured if the conditions of laboratory research and production processes are identical. This mostly applies to the laboratory seal, which must match the production seal. The existing state of affairs does not meet this condition. For many decades, laboratory compaction was carried out by pressing asphalt concrete mixtures under a pressure of 20 MPa with vibration up to 40 MPa. Western European researchers and builders have been aware of this problem for more than 50 years. Due to this, fundamentally new methods of laboratory compaction appeared in the world (impact and vibration-impact type, rolling with metal and pneumatic rollers, displacement with pressure in the case of rotary presses). In Ukrainian practice, such methods are practically not used, despite the fact that the first rolling press was developed in KADI. The results of comparative studies of asphalt concrete compacted by the following methods: pressing, sector rolling, and rotary compaction are presented. Attention to the advantages and disadvantages of each of them is accepted. Keywords: asphalt concrete mixture, compaction by pressing, rolling, rotary shear, kinetics of gradual compaction, bitumen content.

Fracture failure analysis and research on super-large-diameter roll

A super-large-diameter roll in a roller press suddenly broke in operation after less than four months. A series of experimental tests were carried out to determine the cause of roll failure to evaluate the chemical composition and mechanical properties. A detailed analysis involving macroscopic features and microstructure analysis of the material was performed. Fatigue features were observed on the fracture surface. The crack grew from the edge of the inner hole and extended from the inside to the outside. Further analysis showed that the material had good tensile properties but poor impact toughness. In addition, the roll had an enormous internal stress, far more significant than its working load. The fracture of the roll was a fatigue fracture under unreasonable heat treatment conditions and inner hole design. A larger hole depth and perfect heat treatment are recommended.

Prediction and Optimization of Wear Depth on Rectangular Tube Surface in Roll Forming

The outer surface of the tube is worn under the interaction between the velocity difference and rolling pressure, in the process of rolling the circular tube into a rectangular tube. In order to predict the wear depth, according to the characteristics of roll forming, the causes of wear in the forming process are analyzed. The finite element model of rolling forming was established based on Archard theory, and the 40 mm × 27.5 mm × 3 mm SUS304 stainless steel rectangular tube was simulated. The simulated results were compared with a test rolling of the steel tubes of the same size material, and the wear areas were found to be highly consistent, which verified the accuracy of the finite element model. The effects of the friction coefficient and the flat roller angular velocity on the simulation results which wear depth were analyzed, and the regression model of wear depth was established by response surface method. The results showed that the flat roller angular velocity had the greatest effect on wear depth; moreover, the flat roller friction coefficient was the second, and the vertical roller friction coefficient was the lowest. The minimum value of the regression model was optimized, the simulation value of the optimization scheme was compared with the optimized value, and the error of the two values was less than 5%, which verified the correctness of the regression model. The wear depth of the rectangular tube after optimization was reduced by 64.69% compared with that before optimization, which verified the effectiveness of the optimization results.

Parameter Optimization of Large-Size High-Speed Cam-Linkage Mechanism for Kinematic Performance

The cam-linkage mechanism is a typical transmission mechanism in mechanical science and is widely used in various automated production equipment. However, conventional modeling methods mainly focus on the design and dimensional synthesis of the cam-linkage mechanism in the slow-speed scenario. The influence of component dimensions is not taken into consideration. As a result, the model accuracy dramatically falls when analyzing large-size cam-linkage mechanisms, especially in high-speed environments. The kinematic aspects of cam design have been investigated, but there are few studies discussing the motion characteristic and accuracy analysis models of the large-size cam-linkage mechanism under high-speed scenarios. To handle such issues, this paper proposes a parameter optimization methodology for the design analysis of the large-size high-speed cam-linkage mechanism considering kinematic performance. Firstly, the mathematical model of the cam five-bar mechanism is presented. The cam curve and motion parameters are solved forward with linkage length and output speed. Then, a particle swarm-based multi-objective optimization method is developed to find the optimal structure parameters and output speed curve to minimize cam pressure angle and roller acceleration and maximize linkage mechanism drive angle. A Monte Carlo-based framework is put forward for the reliability and sensitivity analysis of kinematic accuracy. Finally, a transverse device of a sanitary product production line is provided to demonstrate the applicability of the proposed method. With the parameter optimization, the productivity of the transverse device is doubled, from 600 pieces per minute (PPM) to 1200 PPM.

Analysis of force and deformation parameters in corrugated clad rolling

Corrugated clad rolling is an emerging and promising technology to produce composite plates with a three-dimensional corrugated interface and excellent performance. A new analytical model is proposed to predict and analyze force and deformation parameters in corrugated clad rolling using the slab method, which solves the problem that there is no suitable analytical model to improve the precision of automatic production control. The analytical model is proposed by selecting a differential element perpendicular to the rolling direction, analyzing the corresponding differential equilibrium equations and calculating the integral constants according to the yield and boundary conditions. Dynamic rolling forces under different contact states between the composite plate and rolls are presented creatively considering the special features of the new corrugated clad rolling that there are multiple complex shapes and stress states in the deformation zone and that there are various outlet conditions of the corrugated composite plate. The accuracy of the proposed analytical model is verified by the comparisons of the calculated values from the model, the FEM results, and the experimental measurements. The error of the proposed model is within 7.36%. The specific rolling pressure distributions along the projected contact arc, the specific horizontal stress distributions along the projected contact arc, the dynamic rolling forces, and the positions of the lower neutral point can be conveniently and accurately calculated by the proposed model, which can help to analyze the mechanism of the corrugated rolling with the variation of the rolling reduction rate, the shear yield stress ratio and the friction factor ratio. The proposed analytical model of dynamic rolling force and deformation parameters is especially suitable for the analysis of the new corrugated clad rolling and can provide technical support for the control precision of automatic production.

REVIEW: PELUANG REKAYASA PROSES PENGOLAHAN DAN DIVERSIFIKASI AMPING BERAS SEBAGAI PRODUK UNGGULAN DAERAH KABUPATEN SAMBAS

The quality of the amping of rice is still low, has a dull color, not thin enough so that the texture is hard, and there is still a lot of mixture of husks and black rice. In addition, to be able to enjoy rice amping, consumers must prepare other additional ingredients such as grated coconut with brown sugar, so the practical level of the product it still needs to be improved and consumers can immediately enjoy rice amping products easily and practically. Improvements in the quality of Amping Sambas products need to be carried out through improving processing processes and diversifying rice amping products in accordance with current trends in the market. Improvements to the process of making Amping Sambas can refer to existing processes, among others, by paying attention to the raw materials for manufacture, using rice from varieties that have moderate amylose content (20-25%), soaking at room temperature for 7-8 hours, doing roasting is carried out at a temperature of 302 oC for 41 seconds, and the flattening is carried out in 2 stages, stage 1 at 45 oC, stage 2 at roller pressure of 145 ± 5 kg/cm2 and a temperature of 75 ± 5 oC. to increase consumer acceptance of Amping Sambas products, diversify products, including in the form of Iron Fortified Chocolate Flavored Rice Flakes, Roasted Rice Flakes in Cereal Bars, and Cereal Bars Made from Glutinous Rice Flakes and Sunnah Foods.

Three-dimensional study on the interaction between a container ship and freak waves in beam sea

Freak wave occurs unexpectedly in the ocean with an extreme wave crest and focused wave energy, resulting in many marine accidents. The interaction between a container ship and freak waves in beam sea is studied in this paper to better understand the influence of freak waves on ships. A three-dimensional in-house solver is developed and validated for the freak wave generation and the wave-ship interaction. Characteristics of the interaction process, motion responses of the ship and the green water loadings induced by the freak waves are obtained and analyzed. Comparisons are carried out to reveal the influences of the freak wave crest and sequence on the roll, heave and impact pressures. Relations between motion responses of the ship and the green water event are discussed. Influences of ship speeds on the wave-ship interaction are addressed.

Aluminum/steel rolled composite finite element secondary development simulation and experimental study

Given the significant difference in the properties of the two metals, the rolled composite has a severe problem of uncoordinated deformation and low bond strength. The effect of the same diameter and different diameters of the rolls and single roll drive on the composite plate’s coordinated deformation and bond strength is investigated. Simulation modeling employs finite element (FE) secondary development, and the plate warpage mechanism is analyzed by combining synchronous and asynchronous rolling experiments. The aluminum side is subjected to compressive stresses in the rolling direction during the rolling process. The steel side is subjected to tensile stresses in the rolling direction. The roll diameter in contact with the aluminum plate is reduced, the rolling pressure is distributed more evenly along the vertical plate section direction, improving deformation coordination. The side of the roll that touches the aluminum is driven, and the bimetal starts to bond closer to the exit of the roll. The frictional stresses and bending moments between the bimetallic interface are smaller, resulting in better deformation coordination and higher bond strength.

Influence of Roll Speed during Roll Compaction and Its Effect on the Prediction of Ribbon Solid Fraction.

Influence of the roll speed (RS) during roll compaction on ribbon, granule, tablet properties and its effect on the prediction of the ribbon solid fraction at-gap is often neglected or controversially discussed. The aim of this study was to investigate the effect of the RS systematically. Microcrystalline cellulose (MCC) and lactose were compressed at several maximum roll pressures (Pmax) and RS combinations using a gap-controlled roll compactor. The ribbon solid fraction after elastic recovery (SFribbon), granule size distribution and tabletability of the granules as well as the ribbon solid fraction at-gap (SFgap) were measured. The Midoux number (Mi), derived from the Johanson model, was used to predict the ribbon solid fraction at-gap (SFMi). The measured SFgap and the predicted SFMi lead to a prediction accuracy (PA) of the Midoux number. The results are highly dependent on the material used and the applied Pmax. Higher plasticity of the material leads to a reduction in SFribbon and granule size with increasing RS. However, this effect can be overcome or reduced by adjusting Pmax above the yield pressure of the used material. These results allow for higher roll speeds as a potential upscaling method in roll compaction. On the other side, the PA of the Midoux number was also reduced with increased RS for MCC and had no effect for lactose. Thus, RS seems to be an important factor in the prediction of roll compaction processes and prediction models should include RS as a parameter to improve their accuracy.

The Use of Thermography to Determine the Compaction of a Saddle-Shaped Briquette Produced in an Innovative Roller Press Compaction Unit

Abstract The unit compacting pressure in the fine-grained material consolidation process in the roller press can reach >100 MPa and is a parameter that results, among other things, from the properties of the consolidated material and the compaction unit geometry. Achieving the right pressure during briquetting is one of the factors that guarantee the proper consolidation and quality of briquettes. The distribution of the temperature on the surface of the briquettes correlates with locally exerted pressure. The present work aimed to analyse the briquetting process of four fine-grained materials in a roller press equipped with saddle-shaped briquette-forming rollers based on images obtained from the thermography conducted immediately after their consolidation. The tests were carried out in a roller press that was equipped with forming rollers of 450-mm diameter and having a cavity with a volume of 4 cm3, as described by patent PL 222229 B1. Two mixtures of hydrated lime with 9.1 wt% and 13.0 wt% water, a mixture of scale and a mixture of electric arc furnace (EAF) dust were used for the tests. In most mixtures, the highest temperatures were achieved in the middle-upper part of the briquettes. The briquettes from the EAF dust mixture heated locally the most on the surface up to 37.7 °C. The difference between the maximum briquette temperature and the ambient temperature was 20.2 °C.

Analysis of Coupling Gear on Roller Press Cement Mill

This study aims to determine the causes of failure in the coupling gear, reduce or minimize damage that occurs in the coupling gear, determine the hardness of the coupling gear material, and to determine the level of wear and tear on the coupling gear. This research was conducted from July to October 2022, at PT. Semen Padang, ITP Mechanical Engineering Laboratory, FT-Unand Mechanical Engineering Metallurgical Laboratory. The test procedures used in this study are first to identify the damage, hardness testing on the coupling gear, wear testing on the coupling gear. After observing, the types of damage to the coupling gear are obtained, namely in the form of wear. The types of wear and tear on the coupling gear are scoring, plastic flow, and pitting. Based on the results of the hardness test on the first specimen, the average hardness was 41.1 HRC and on the second specimen, the hardness average was 33.5 HRC and on the third specimen, the hardness average was 34.9 HRC. The specimen that has the highest average hardness value is the first specimen with an average hardness of 41.3 HRC. the wear level in test 1 is 0.008 and in test 2 the wear level is 0.004 and in test 3 the wear level is 0.004 and in test 4 the wear level is 0.004 and in test 5 the wear level is 0.004. From the wear test it was found that the type of wear on the coupling gear material is classified as abrasive and fatigue wear because the two materials are rubbing against each other and the eroded material does not stick to each other and there is also fatigue due to the load that is applied continuously so that the material or coupling gear is worn out.