In today's production and manufacturing industries, the laser cutting method is the broadly used nonconventional, advanced, non-contact type machining process. It has various advantages in using to cut or engrave almost all kinds of materials. In this study the effect of laser engraving parameters on filter paper were quantified using a mathematical model. The main objective of this study was to assess the individual and interaction effect of the input parameters on the surface quality of engraved portion under the experimental conditions that were based on the experimental design. From the experiment it was found that the laser power has the significant effect on the surface roughness. The interaction effect of the speed and number of dots per inch created by nozzle of the laser engraving machine and the quadratic effect of speed also have a significant effect on the output surface quality. It is seen that the roughness increases with the increase in the laser power. Also, it was found that the combination of low laser power and mid engraving speed can results in the good surface quality. Similarly, combination of low speed and DPI results in the good surface quality. Accordingly, interaction effect of low power and high DPI results the better surface quality. The best optimal setting was at 8W of laser power, 205.895 mm/sec of engraving speed and 299.9 numbers of dots per inch, the roughness was found as 5.5693 µm with the percentage error of 0.53%.
Table of Contents
1. INTRODUCTION
1.1 Surface roughness
1.1.1 Surface roughness measurement
1.1.2 Roughness parameters
1.2 Laser cutting process
1.3 Problem statement
1.4 Thesis objective
2. LITERATURE REVIEW
3. DESIGN OF EXPERIMENT
3.1 Experimental studies
3.2 Why design of experiment
3.3 Central composite design
3.4 Response surface methodology
3.4.1 RSM step-by-step application
4. EXPERIMENTAL WORK
4.1 Selection of input factors and output response
4.2 Sample
4.3 Instruments used
4.4 Methodology
4.4.1 Problem formulation
4.4.2 Literature survey
4.4.3 Trial runs
4.4.4 Design matrix creation
4.4.5 Conduction of experiment
4.4.6 Data analysis and interpretation
4.4.7 Confirmation experiment
4.4.8 Conclusion
5. Results and discussion
5.1 Development of mathematical model
5.1.1 Validation of model
5.2 Effect of process parameters on response
5.2.1 Contour plots
5.3 Optimization
5.4 Confirmation test
5.4.1 Percentage error
6. Conclusion and future scope
6.1 Conclusions
6.2 Future scopes
7. REFERENCE
Project Goals & Core Themes
The primary objective of this research is to optimize the operating parameters of a CO2 laser engraving system to improve surface quality on filter paper for microfluidic applications, utilizing Response Surface Methodology (RSM) to develop predictive mathematical models.
- Optimization of laser power, engraving speed, and DPI settings.
- Application of Central Composite Design (CCD) for experimental planning.
- Quantitative analysis of surface roughness (Ra) as a response variable.
- Verification of optimal settings through confirmation tests and error analysis.
Excerpt from the Book
1.3 Problem statement:
If a manufacturer wishes to introduce laser engraving as a way during a manufacturing process, it's necessary to review the effect of the method during a new material. Variety of preferred characteristics like accuracy of the cut and quality of the surface finish are often specified and also process characteristics like high speed and low power usage are often also stipulated. It’s then necessary to vary the laser input parameters and test whether or not the specified quality features are achieved or not. This procedure is typically performed by skilled workers. However, this procedure of selection of parameters is predicated on trial-and-error and is typically time-consuming. Moreover, the conventional one by one technique isn't systematic and typically doesn't cause an optimised combination of laser engraving parameters. A systematic study, supported Design of Experiment (DOE) techniques followed by the analysis of the results using Response Surface Methodology (RSM), will allow the detection and visualisation of the interactive effects of the input parameters on the results. Once a study of this type has been done, the optimum combinations of laser cutting parameters are often selected then wont to produce the desired specifications.
The present work has been undertaken keeping into consideration the following problem:
Smoother channel boundaries are required in the study of paper based system. Therefore micro-precision is required in order to get the smoother surface of the paper so that different investigations on the miniature system on paper can be done.
It is difficult to engrave on paper due to different operating parameters of the engraving machines, so it is important to investigate the range of operating parameters to engrave on the paper.
Optimal combinations of operating parameters need to be investigated to get the smoothened surface on paper.
Summary of Chapters
INTRODUCTION: Provides an overview of laser technology, emphasizes the significance of surface roughness in microfluidics, and outlines the research objectives.
LITERATURE REVIEW: Examines previous studies on laser cutting and engraving parameters across various materials to establish the research context.
DESIGN OF EXPERIMENT: Details the methodologies used for experiment design, specifically focusing on Response Surface Methodology (RSM) and Central Composite Design (CCD).
EXPERIMENTAL WORK: Describes the materials, instruments, and specific procedures, including trial runs and the development of the design matrix, used for conducting the laser engraving experiments.
Results and discussion: Analyzes the experimental data using ANOVA, develops a predictive mathematical model for surface roughness, and identifies optimal parameter settings.
Conclusion and future scope: Summarizes the findings regarding optimal engraving parameters and suggests potential future research directions in microfluidic device fabrication.
REFERENCE: Lists all scientific sources and literature cited throughout the project report.
Keywords
Laser Engraving, Surface Roughness, Filter Paper, Microfluidics, Response Surface Methodology, Central Composite Design, Optimization, CO2 Laser, ANOVA, Process Parameters, Manufacturing, Experimental Design, Predictive Modeling, Laser Cutting, Surface Quality
Frequently Asked Questions
What is the core focus of this project?
The project focuses on optimizing the operating parameters of a CO2 laser engraving machine to achieve high-quality, smooth surface channels on filter paper intended for microfluidic applications.
Which specific material is used in the experiments?
Filter paper with a diameter of 125 mm and a thickness of 0.23 mm is used as the sample material throughout the study.
What is the primary goal of the research?
The primary goal is to determine the optimal combination of laser power, engraving speed, and dots per inch (DPI) to minimize surface roughness (Ra) on the engraved portions.
Which methodology is employed for the study?
The study utilizes Response Surface Methodology (RSM) combined with Central Composite Design (CCD) to plan experiments and model the relationship between input parameters and surface quality.
How is the experimental data analyzed?
Data is analyzed using the statistical software Design Expert 12, which performs Analysis of Variance (ANOVA) and regression analysis to identify significant factors and their interactions.
What are the key independent variables in this experiment?
The independent variables (process parameters) are Laser Power (A), Engraving Speed (B), and Dots Per Inch (C).
What significance does the mathematical model hold?
The mathematical model allows for the prediction of surface roughness outcomes and the identification of optimal process conditions within the studied experimental range.
What was the outcome of the optimization process?
The optimization yielded an ideal setting of 20% laser power, 82.358% engraving speed, and 299.9 DPI, resulting in a minimal surface roughness of approximately 5.5693 µm.
How was the accuracy of the model verified?
The model was verified through confirmation experiments, where measured results were compared against predicted values, yielding a low percentage error of 0.53%.
Are the individual parameters like speed or DPI significant on their own?
According to the ANOVA results, speed and DPI do not have a significant effect on the output independently, but their interaction effect and the quadratic effect of speed are highly significant.
- Citation du texte
- Debashish Gogoi (Auteur), 2020, Optimization of Operating Parameters of Laser Engraving for Surface Roughness, Munich, GRIN Verlag, https://www.grin.com/document/1144641
