Engraving Process Research Articles

Optimization of Wood-Based Birch Plywood CO2 Laser Engraving Process Parameters with Taguchi Method

In this study, the optimization of the parameters used in the engraving process of wooden birch plywood material with a CO2 laser machine was investigated using the Taguchi method. An industrial laser machine with a 150W glass tube was used during the experimental examination process. The basic parameters for engraving wooden surfaces include laser power (P), engraving speed (S) and laser head height (F). The engraving depth (D) and engraving width formed on the surface during the engraving process are the main factors that determine the aesthetics of the product. Taguchi L25 orthogonal array was used in the experiments to determine and optimize the highly important parameters. The optimum combination of parameters in the laser engraving process was then evaluated. The research results showed that the effect of P and S factors played a leading role, and the F parameter had a small effect on the depth of wood scraping. Optimization results found that F:5, S:100 and P:30 gave the best engraving depth optimization, while F:6, S:300 and P:10 gave the lowest engraving depth optimization result.

Machine learning and design of experiments for optimizing laser-engraved micro fresnel lens mould

This research examines the application of Laser Engraving to produce micro Fresnel Lenses on aluminum plates, a novel application of this non-conventional machining method. The research explores the effects of the scan speed, laser power with number of cycles on the roundness deviation using a L9 orthogonal array. Multiple analytical methods, including the Taguchi method, Random Forest Algorithm with sensitivity analysis, are employed to optimize process and predict the outcomes. In this study, a thorough analysis of the fabrication of a micro Fresnel lens on Aluminum plate (10 mm × 10 mm × 2 mm) using fiber laser of wavelength 1064 nm is presented. The study finds that laser power has most significant effect on the roundness deviation, followed by the number of the cycles and scan speed. Scan Speed ranges from 500 to 700 mm s−1, the Power ranges from 25 to 35 Watts, and the Number of Cycles ranges from 100 to 200. Optimal conditions are identified as 700 mm/s scan speed, 25 W power, and 100 cycles. Microscopic analysis confirms roundness deviation under these conditions. Comparisons between analytical approaches and experimental results reveal that both the Taguchi method and Random Forest Algorithm align closely with experimental outcomes, with the Random Forest Algorithm showing slightly higher accuracy (6.18 percentage points closer to experimental results). This research addresses a gap in comparative studies evaluating traditional statistical methods against modern machine learning algorithms for process optimization in laser machining. It combines knowledge from optics, materials science, and laser machining, utilizing advanced methods and technologies that have only recently become accessible. The findings provide valuable insights for future applications of micro Fresnel lenses on aluminum plates and contribute to the understanding of laser engraving processes for precision optical components. Between the Random Forest Algorithm and the Taguchi method, Random Forest Algorithm fits more closely to the experimental result. Random Forest Algorithm prediction is closer to experimental result by about 6.18 percentage points compared to the Taguchi method prediction.

Research on dynamic characteristics of interior ballistics process engraving based on the coupling method

Study of the engraving process is significant for interior ballistics. Due to the high transient and strong nonlinear characteristics of the engraving, research on the engraving mechanism is challenging. In this paper, based on the one-dimensional two-phase flow model of interior ballistics coupled with explicit dynamics software, finite element simulation of the engraving is carried out to obtain the changes of parameters during the engraving process, and the dynamic characteristics of the projectile engraving are discussed. By comparing the simulation results with the experimental data, the accuracy of the coupling method in this paper is verified. The relationship between the structural parameters of the sealing band and the extrusion resistance is revealed, and the influence of the extrusion resistance on the dynamic characteristics of the projectile is demonstrated. The simulation results can provide an essential reference for selecting a reasonable sealing band structure.

Study on the coupling calculation method for the launch dynamics of a self-propelled artillery multibody system considering engraving process

The launch dynamics theory for multibody systems emerges as an innovative and efficacious approach for the study of launch dynamics, capable of addressing the challenges of complex modeling, diminished computational efficiency, and imprecise analyses of system dynamic responses found in the dynamics research of intricate multi-rigid-flexible body systems, such as self-propelled artillery. This advancement aims to enhance the firing accuracy and launch safety of self-propelled artillery. Recognizing the shortfall of overlooking the band engraving process in existing theories, this study introduces a novel coupling calculation methodology for the launch dynamics of a self-propelled artillery multibody system. This method leverages the ABAQUS subroutine interface VUAMP to compute the dynamic response of the projectile and barrel during the launch process of large-caliber self-propelled artillery. Additionally, it examines the changes in projectile resistance and band deformation in relation to projectile motion throughout the band engraving process. Comparative analysis of the computational outcomes with experimental data evidences that the proposed method offers a more precise depiction of the launch process of self-propelled artillery, thereby enhancing the accuracy of launch dynamics calculations for self-propelled artillery.

Numerical simulation of the coupled dynamics model of the projectile engraving process

AbstractThe projectile engraving process directly influences the projectile motion in‐bore and impacts the firing accuracy, firing safety, and barrel life of the gun. For this reason, attention has been focused on this research topic. To address the limitations of the “instantaneous engraving” hypothesis adopted in the classical interior ballistic theory, the VUAMP user subroutine, one of ABAQUS's secondary development interfaces, is utilized in this paper to realize the modeling and numerical simulation of a coupled dynamics model of the projectile engraving process. In addition to facilitating engineering applications, a polynomial fitting formula of the engraving resistance obtained by simulation is proposed and then used as a supplement to establish a closed and solvable interior ballistic model considering the projectile engraving process. By comparing with test data, the simulation accuracy of the coupled dynamics model is verified. Simulation results reveal that the engraving process takes 3.8 ms, accounting for 26% of the whole launch process, which takes 14.6 ms, demonstrating that the process is not instantaneous. The results of this paper can serve as a reference for future studies on the coupled solution of the projectile engraving process and interior ballistics of guns or gun‐like equipment.

Dynamic engraving characteristics of nylon belt under different charge conditions

Abstract In the present study, a 105 mm short tube gun system was designed to conduct the firing experiments under low charge conditions, which could precisely obtain the projectile displacement data and projectile base pressure data during the engraving process. Besides, a 3-dimensional dynamic engraving FEM-SPH model was established by coupling the internal ballistic process to much authentic investigate the engraving characteristics of the projectile, which were verified and compared through the experiment. On this premise, the influence mechanism and engraving features of the nylon belt were numerically calculated under higher charge conditions. The comparison between the experimental recovery belt and the numerical calculation results shows that the damage to the front of the nylon belt is axial compression wear, while the damage to the back of the nylon belt is circumferential shear wear. The direction of force exerted by the slope chamber and the projectile body on the belt was inconsistent, causing a bulge in the middle of the nylon belt. The more rapid the average boosting rate, the stronger the instantaneous impact on the nylon belt, the larger the stress and the strain damage on the nylon belt, the higher the pressure at the end of the engraving process and the greater the maximum engraving resistance. When the average boosting rate increased from 2.7 MPa⋅ms−1 to 33.0 MPa⋅ms−1, the engraving time was shortened by 73.9%, while the maximum engraving resistance increased by 78.2%.

Strong impact and engraving characteristics of multi-layer metallic materials under a two-stage combustion condition

Abstract This work is focused on the strong deformation motion mechanism of multi-layer metallic materials under extreme pressure conditions accompanied by a strong impact effect between the projectile composed of multi-layer metallic materials and the steel barrel of the launcher itself. Here, this transient engraving process of the projectile with complicated stress–strain based on a new type of structure and propulsion pattern is firstly studied by proposing a new physical and mathematical model with a coupling of dynamical equations and two-stage combustion ballistic equations. Comparisons of engraving distance of computational results are done with experimental studies, and a reasonable match has been obtained in these comparisons. Further, the thickness effect of the metal jacket of the projectile on the engraving stress and deformation level is analyzed to obtain universal engraving resistance equations. The results have also shown that the projectile's whole transient deformation motion process in the launcher can be divided into three periods due to the initial slide impact effect under the first-stage propellant gas and the later propelling effect as the second-stage propellant is ignited. However, the engraving durations are all less than 0.7 ms with different levels of elastic-plastic deformations between multi-layer metallic materials for different conditions.

Sustainable Laser Induced Supercapacitors from Cork Natural Substrates

A novel type of eco-friendly and cost-effective supercapacitor has been developed by fabricating interdigitated and squared supercapacitors made of porous graphitic carbon electrodes and Polyvinyl alcohol (PVA) electrolyte. The electrodes were fabricated using a simple, fast, and low-cost laser engraving process, using visible irradiation wavelengths (450 nm) and performed under ambient conditions, resulting in highly three-dimensional, electrically conductive, and porous graphitic carbon structures.By adjusting the laser power and wavelength, it was possible to produce electrode materials with highly porous and high surface area morphology, which are promising for electrochemical applications. Spectral investigation using Raman and FTIR spectroscopies confirmed the formation of graphitic carbon structures and the full conversion of the cork precursor under visible laser irradiation.The obtained electrodes exhibited excellent supercapacitive behavior when exposed to a PVA electrolyte, achieving a specific areal capacitance of up to 11.24 mF/cm2 with PVA at 30% laser power. The supercapacitive properties showed excellent stability over time, with no significant loss after 10000 charge/discharge cycles.To evaluate the performance of the new supercapacitors, linear electrodes were used as working electrodes in a three-electrode configuration electrochemical cell. The electrodes showed diffusion-limited electrochemical behavior with fast heterogeneous electron transfer rates (HET), which was superior to that of traditional glassy carbon electrodes.The innovative and efficient electrode fabrication method presented in this study, which utilizes low-cost instrumentation, environmentally friendly fabrication methods, and Earth-abundant precursor materials, shows great promise for producing large-scale "green" electrochemical sensing platforms and devices in the future.

Intelligent characterization of spark-assisted chemical engraving (SACE) process using time series classification

Intelligent characterization of spark-assisted chemical engraving (SACE) process using time series classification

ANALISIS RISIKO KERJA PADA PROSES PEMBUBUTAN MENGGUNAKAN METODE HIRARC

Poor management of occupational safety and health (OSH) has an impact on occupational accidents. This results in losses for both the individual worker and the company. Therefore, the occupational hazard accident risk analysis was carried out using the HIRARC (Hazard Identification Risk Assessment and Risk Control) method. Data collection was conducted from the business owners of SSBC (Sanggar Sarana Baja Cakra) Welding and Turning Shop, located in Cakranegara, Mataram, West Nusa Tenggara. There are 3 work activities for risk identification, namely the clamping process, the engraving process and the drilling process. The results of the analysis show that the highest level of occupational risk occurs during clamping and engraving process. For drilling, it's in low level of risk. As for risk management, it is mainly done for high-risk level. Immediate improvement is needed by providing personal protective equipment (PPE) to workers to reduce these risks. Based on these results, business owners can do evaluation on his business so occupational accidents can be in the workplace.

THE EFFECT OF CO2 LASER ENGRAVE PARAMETERS ON SURFACE ROUGHNESS ON POLYMETHYLMETHACRYLATE (PMMA)

The investigation of the laser engraving process has been the focus of a significant amount of research in the field of laser machines. On the surface of the material, gaps and imperfections will appear as a natural result of the engraving process. It is widely held that the surface texture of a material has a significant impact on the material's mechanical qualities, as well as its functional performance and aesthetic appeal. As a result, the purpose of this study is to investigate the influence that different process parameters have on the PMMA (polymethylmethacrylate) surface during the engraving process. PMMA was used throughout this investigation in the engraving process, which was carried out by a machine equipped with a 40W CO2 laser tube. In order to explore the effect that laser engraving has on materials, a total of 25 separate experiments were carried out in line with the Taguchi design principles. It has been investigated how surface roughness (Ra), as well as total machining time, is affected by the laser power, scanning speed, scan gap, and nozzle distance that are considered to be input factors. According to the findings, the surface roughness of the sample had a value that varied from 0.810 to 5.159 micrometres when measured in terms of distance. The factor that has the greatest influence on the Ra value is the scanning speed, which is followed by the nozzle distance, laser power, and scan gap. On the other hand, the amount of time necessary for the machine to finish engraving on the sample can range anywhere from 58 to 135 seconds, with the scanning speed being the characteristic that has the most influence on this figure.

The simulation and experimentation of spiral flat bottom engraving

The study uses rigid-plastic finite element (FE) DEFORM TM 3D software to investigate the plastic deformation behaviour of spiral flat bottom engraving. The finite element analysis assumes that the spiral flat bottom is a rigid body. During the engraving process, the deformation causes an increase in temperature and wear inside the blank. The FE analyses investigate the effects of cutting speed, depth of cut, and the feed of the workpiece on the damage, effective strain, stress, temperature, and wear induced within the workpiece. The simulation results confirm the suitability of the DEFORM TM 3D software for modelling the spiral flat bottom engraving. Comparisons of engraving of spiral flat bottom with clockwise and counter-clockwise have been performed. The analysis of following stress-strain simulation has been predicted by machine learning in this study. Eventually, the experiment of spiral flat bottom engraving is used.

Research and integrate laser marking system on plastic materials using 355 nm UV laser

This article presents the results of research, design and integration of a laser equipment system on plastic materials using a UV laser of wavelength 355 nm, power of 5 W, integrated from semi-finished modules available on the market. The research team investigated the influence of technical parameters on the UV laser engraving process on plastic materials such as wavelength, output laser power, pulse width, engraving speed, engraving area size, electricity source... As a result, the research team has come up with a set of parameters for the manufacturing equipment system for a number of specific plastic materials. Some experimental UV laser engraving products on plastic materials of the manufactured equipment system show images with high sharpness and contrast, small heat-affected areas, can engrave sizes as small as micrometers, with a high speed. Research results showed that UV laser equipment is a good choice for laser applications in the semiconductor industry, micro-mechanics, medicine and peripheral equipment...

Enhanced sensitivity and detection range of a flexible pressure sensor utilizing a nano-cracked PVP hierarchical nanofiber membrane formed by BiI3 sublimation

The development of a highly sensitive and wide-range flexible pressure sensor is great significant to realize the practical applications in human–computer interaction, health monitoring, and motion detection. Here, a dielectric layer of nano-cracked polyvinyl pyrrolidone (PVP) hierarchical nanofiber membrane (HNM) was fabricated by sublimating BiI3 from an electrospun BiI3/PVP composite nanofiber membrane (NM) via one-step annealing process. The upper and lower electrodes of porous laser-induced graphene (LIG) were produced through the engraving process on polyimide (PI) substrates. Subsequently, a flexible capacitive pressure sensor was constructed by assembling the middle PVP HNM dielectric layer with upper and lower LIG electrodes, which demonstrates enhanced sensitivity and detection range for motion posture recognition. Experimental results indicate that compared with traditional PVP NM-based pressure sensor, the assembled sensor in this work exhibits 22 times higher sensitivity (at 2–100 kPa) and 4 times wider detection range (0–200 kPa). Additionally, the sensor boasts a fast response/recovery time of 29/41 ms, an exceptionally low detection limit of 2.7 Pa, and an outstanding stability of 3000 cycles. With the aid of a convolutional neural network (CNN) algorithm, a shooting posture recognition system was developed by multiple sensors to accurately identify (accuracy: 93.89 %) and guide the shooting postures of basketball players.

Unveiling the Sacred Journey: The Birth of a Woodblock-Printed Buddhist Canon in the Great Hangzhou Region of the Southern Song Dynasty

This article delves into the literature sources and historical origins of the initial section of the Qisha Canon, a renowned block-printed Chinese Buddhist Canon carved in the greater Hangzhou region during the Song and Yuan dynasties. The existing first twelve volumes, preserved in Japan, exhibit distinct features characterized by notable stylistic script, textual content, and layout. These features indicate their direct lineage from handwritten Buddhist canons of the Northern Song Dynasty rather than from previously printed versions. The utilization of handwritten sources as the foundation for engraving, despite the availability of established printed editions, demonstrates an underappreciated complex relationship between manuscripts and printed canons of the period. Throughout the engraving process of the twelve volumes, the majority of contributors were found to be local commoners, with minimal participation from Buddhist followers. The fluidity of the fundraising locations underscores the inherent instability of such projects. Initially commencing in Liaoqin’s hometown in Huzhou, the project was subsequently transferred to the imperial city of Lin’an prefecture (modern Hangzhou), which shared a border with Huzhou. Ultimately, it found its new location in Pingjiang Prefecture (modern Suzhou). Moreover, this research presents a comprehensive analysis of 195 colophons, delving into the prices, locations, and backgrounds of the characters mentioned. This meticulous examination offers a vivid depiction of the religious and social landscape of the period and provides valuable insights into the recording conventions employed in these colophons.

REPRODUCTION AND POPULARIZATION OF MORALIZING FAMILY SCENES IN JEAN-BAPTIST GREUZE’S PRACTICE: PREPARATION AND ORGANIZATION OF THE PROCESS

Jean-Baptiste Greuze (1725-1805) was famous for portraits and moralizing family scenes. At the same time, he achieved exceptional success in popularizing his art by engraving genre compositions. This article examines preparatory modellos for his family scenes and the organization of their engraving process. This aspect of his activity has not been yet studied, and his drawings are little covered in Russian-language literature. The study reconstructs step by step the activity of Greuze as a popularizer of family scenes in prints on the basis of the documents available to the author, analysis of original drawings and prints from Russian and foreign collections. It highlights such aspects of the creative process as preparation of compositions for engraving, achievement of specific qualities in the drawings in connection with the technologies of further reproduction, interaction with engravers and organization of creative and technical works within the special association. The author concludes that the master chose a limited number of engraving techniques by the criterion of the most accurate reflection of the artistic properties of the originals. By engaging a special circle of engravers, he created a monopoly association to control the process of creating, producing and selling prints. As a result, Greuze achieved outstanding and specific artistic qualities in his drawings intended for further duplication. Even contemporaries paid attention to the excellent quality of Greuze’s engravings, which amazingly accurately conveyed the individuality of his technique, and singled them out among the mass production of general circulation in eighteenth-century France. This system of creation and popularization of drawings was innovative in the field of engraving. It reveals practical and business abilities of the outstanding artist, as well as a new insight into Greuze’s artistry.

Experimental Study and Numerical Calculation of Projectile Dynamic Engraving Process

The high temperature and pressure gas in the combustion chamber pushes the projectile towards the muzzle during the firing of the gun. The projectile belt is squeezed and deformed by the forcing cone. In order to study the dynamic engraving characteristics of the projectile, a short-barrel gun launcher was designed for experimental research. The projectile dynamics and projectile base pressure curves during the engraving process were obtained. Based on the experimental loading conditions, the J-C elastic-plastic model was used to numerically simulate the dynamic engraving process of the copper elastic belt. The deformation process of the elastic belt and the change characteristics of the resistance after the elastic were studied and the intrusion displacement obtained by the numerical calculation was compared with the experimental results and the results are consistent.

Effects of Cylindrical Structure on Bullet In-Bore Action Process

To explore the effects of bullet cylindrical difference on in-bore dynamic engraving resistance and muzzle swing, a finite element model of bullet-barrel interaction is built. With the proposed model, real bore bottom pressure curves are obtained through experiments. In the numerical simulation, the in-bore motion processes of two all-copper bullets with different cylindrical structures are reproduced according to the real bore bottom pressure curves, so as to qualitatively analyze the relationship between bore pressure curves and bullet in-bore motion. The association between curve inflection points and bullet motion is identified, and the engraving forces of the two bullets are found to exhibit roughly the same trend. In addition, there is an abnormal phenomenon that the bullet with a shorter engraving length should have a larger engraving force. This is due to the interaction between the shape of bore pressure curves and the engraving process, as well as the larger muzzle swing caused by straight slotted structures that have a shorter engraving length. The findings of this study can provide a basis for the design of internal ballistics and the further analysis of the effects of in-bore motion on external ballistics.

Effect of ramming initial state on band engraving in smooth-bore guns

Most modern tank guns are high bore pressure smooth-bore guns that often use High Explosive Antiarmor (HEAA) projectile in combat. This paper focuses on the coupled smoothbore gun- HEAA projectile system, and analyses the projectile ramming-band engraving process when a tank fires HEAA projectile. First, a finite element mesh model of the coupling dynamics of a large-calibre tank gun smoothbore barrel and HEAA projectile was established, and the band was discretized by using the Smoothed Particle Hydrodynamics (SPH) method based on the Lagrange mesh. Then, the propellant gas pressure acting on the bore and the base of the projectile was defined by ABAQUS user’s subroutine. Finally, the ramming-engraving process simulations were carried out for the ramming residual stress and strain, ramming tilt and different ramming misalignment distances working conditions respectively. According to the simulation results, the effect of different ramming initial states on the band engraving process was obtained. The conclusion provides some reference for the simulation of the band engraving process.

Modeling and simulation on dynamic engraving process of small caliber armor-piercing projectile with lead-free aluminum filler

In order to reduce the ineffective armor-piercing weight of the small caliber armor-piercing projectile, improve combat effectiveness, and reduce the pollution of lead fillers to the environment, a projectile with aluminum filler was proposed. Taking the small caliber armor-piercing projectile as the research object, using explicit dynamic methods and coupling the classical internal ballistic equations, a numerical simulation model of bullet–barrel interactions during dynamic engraving process was established. And the reliability of the model was verified by the dynamic engraving experiment. Besides, using copper and copper-clad steel (CCS) as the jacket material, and aluminum and lead as the filler material, numerical simulation studies of four schemes were carried out. The result shows that, the aluminum filler projectile will cause a slight increase in the maximum chamber pressure and a slight decrease in the muzzle velocity of the projectile, an increase in the sliding friction force and a decrease in the maximum deformation force, an increase in the contact stress on both sides of the land and a decrease in the contact stress on the land and groove. And the contact stress on the non-driving side is larger than that on the driving side. The average contact stress and the engraving resistance of the Cu-Al case and CCS-Pb case are very close. And the application of Cu-Al projectile may improve the shooting accuracy in the hot barrel conditions compared with Cu-Pb projectile, and achieve the same performance as CCS-Pb projectile.