The Characterization of Surface Texture in Laser Bamboo Engraving: A Metrological Approach

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This article analyzed the surface roughness parameters only on bamboo panels. Bamboos are typically fast-growing perennials, belonging to the tall treelike grasses of the Poaceae family. Therefore, bamboo is not a tree, consequently the bamboo material is not wood. Due to the above reason, the title must be changed accordingly, and the use of “wood” word reconsidered all over the article.

The authors didn't consider the material characteristics closely related to the surface roughness determination, like density, moisture content, etc. Since laser cutting and engraving as a matter of fact is burning in the case of woody materials, density, micro- and macroscopic properties play a significant role in this burning process. Consequently, the surface roughness after the laser treatment will be highly determined by these factors. Not mentioned that the high variability of these characteristics in the woody materials can superpose with the modified roughness values.

In the attached picture you can see how darker the lower density early wood zones are, compared with the lighter high density late wood zones. The early wood and late wood zones are highly irregular, which contribute to the elevated variations of the surface texture.

Other observations:

The introduction doesn’t treat and review the laser cutting and engraving aspects specific to wood and wood-based materials.

 A detailed description of the bamboo material is completely missing in the Materials and Methods chapter (bamboo species used, basic physical characteristics (density, moisture content). It is also indicated to explain how the vessels and pits were considered in the P and R values. 

The number of measurements is high however all engravings were done in one single bamboo board. 

Figure 6 : it is not clear where exactly the measuring paths are located

Figure 10, 11: the pictures are not sharp enough, the measuring paths should be indicated 

Figure 12.: is interesting but not relevant

Figure 15: The P and R values are separate variables, it is not indicated to connect the points.

The inconsistencies in R and P values at different power rates and engraving speeds must be explained. 

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The Quality of English Language is acceptable, just minor revisions needed. 

Author Response

Dear Reviewer,

 

First of all, we would like to thank you for your comments and suggestions on our work. Undoubtedly, all of them have allowed us to think about it, see it from a different point of view, and complete and improve it to its current version.

We will now answer each of your questions. We hope that our answers will meet your expectations.

Thank you very much in advance.

The authors

1.- This article analyzed the surface roughness parameters only on bamboo panels. Bamboos are typically fast-growing perennials, belonging to the tall treelike grasses of the Poaceae family. Therefore, bamboo is not a tree, consequently the bamboo material is not wood. Due to the above reason, the title must be changed accordingly, and the use of “wood” word reconsidered all over the article.

Thank you for your comment. We have changed the word wood to bamboo in the title and throughout the text. In this way the terminology is more precise.

2.- The authors didn't consider the material characteristics closely related to the surface roughness determination, like density, moisture content, etc. Since laser cutting and engraving as a matter of fact is burning in the case of woody materials, density, micro- and macroscopic properties play a significant role in this burning process. Consequently, the surface roughness after the laser treatment will be highly determined by these factors. Not mentioned that the high variability of these characteristics in the woody materials can superpose with the modified roughness values.

In this paper, we propose a procedure to characterize the engraving results on a bamboo sample and the associated uncertainty of the calculated parameters. If the sample's material and composition are altered, the results will differ; however, the procedure can remain consistent. We suggest using Rz as the parameter to characterize the results.

We have included this comment in Conclusions, in order to clarify. Thank you very much for your comments.

3.- In the attached picture you can see how darker the lower density early wood zones are, compared with the lighter high density late wood zones. The early wood and late wood zones are highly irregular, which contribute to the elevated variations of the surface texture.

Sure, and this is one of the reasons that help us to consider Rz as a parameter quite relevant for the physical characterization with contacting metrology. Another posible characterization may be developed with optical characterization, but it is out of the scope of this paper.

We have included the following statement in the paper to address this consideration:

"We have focused solely on characterization using contacting metrology. Further research is encouraged to include and compare results with non-contacting metrology."

Other observations:

4.- The introduction doesn’t treat and review the laser cutting and engraving aspects specific to wood and wood-based materials.

Yes, we completely agree. We focused on developing a procedure to identify the most suitable roughness parameter for evaluating the finish of the engraving on a specific sample. Based on our results, we propose Rz as the most appropriate parameter. However, how this parameter may vary due to laser effects on wood samples is beyond the scope of our study.

We also considered providing a brief explanation of the different algorithms for roughness evaluation and profile filtration. However, we decided to work with standardized parameters and propose a simplified procedure for works where the primary focus is on the engraving.

5.- A detailed description of the bamboo material is completely missing in the Materials and Methods chapter (bamboo species used, basic physical characteristics (density, moisture content). It is also indicated to explain how the vessels and pits were considered in the P and R values.

See comment above

6.- The number of measurements is high however all engravings were done in one single bamboo board.

The results presented in the paper were obtained using the same bamboo board to minimize the influence of significant variations between different boards. Prior to compiling and writing this research, we experimented with various materials and boards, and found that the bamboo board provided the most illustrative example. Each engraving on the board maintained the same design to avoid any influence from changes in laser movements. The variations in engraving parameters, as discussed in the paper, were the primary focus.

7.- Figure 6 : it is not clear where exactly the measuring paths are located

Agreed. We have improved the figure.

8.- Figure 10, 11: the pictures are not sharp enough, the measuring paths should be indicated 

The measurement paths are all located as specified in Figure 6. Figures 10 and 11 provide qualitative images to offer visual details of the engraving effects but any quantitative evaluation.

9.- Figure 12.: is interesting but not relevant

We agree the reviewer about figure 12 is not relevant, however this is an effect that may occur when implementing an engraving procedure. Therefore, we believe it is important to mention this.

10.- Figure 15: The P and R values are separate variables, it is not indicated to connect the points.

The connection is provided to visually highlight the change and so it has been indicated in the figure title.

10.- The inconsistencies in R and P values at different power rates and engraving speeds must be explained. 

Sure, but the scope of the paper is to propose a parameter for roughness evaluation in engraving. The dependence of the values on the engraving parameters will be of interest for achieving the desired engraving results. The variations in R and P values depending on power rates, among other factors, demonstrate that these parameters are effective variables for evaluating the results. In future works, engravers should determine the optimal laser engraving parameters for their specific material to achieve the expected R and P values.

As we consider this quite an interesting comment, we have included a short paragraph about this in the conclusions.

11.- Comments on the Quality of English Language

The Quality of English Language is acceptable, just minor revisions needed.

The article has been reviewed by a native English speaker.

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript presents a valuable experimental approach to evaluating surface roughness in laser-engraved wood using 2D ISO parameters. The identification of Rz as the most representative parameter across various laser settings addresses a clear gap in the current literature. The work is technically sound and methodologically rigorous, supported by an impressive dataset. The manuscript is interesting and presents a novel approach to evaluating surface roughness in laser-engraved wood. However, some parts need clarification and better structure. The topic is novel and directly applicable to both research and industrial settings. However, several areas—especially related to clarity, structure, and justification—require revision to enhance the manuscript's scientific impact and readability.

• Some phrasing is repetitive, it should be reconsidered,
• Introduction, more detailed information should be provided on surface characterization.
• In the discussion section, not only the repetition of the results but also the literature comparison and potential applications could be more emphasized.

The study has high potential and is suitable for publication after substantial revision.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

 

First of all, we would like to thank you for your comments and suggestions on our work. Undoubtedly, all of them have allowed us to think about it, see it from a different point of view, and complete and improve it to its current version.

 

We will now answer each of your questions. We hope that our answers will meet your expectations.

 

Thank you very much in advance.

The authors

This manuscript presents a valuable experimental approach to evaluating surface roughness in laser-engraved wood using 2D ISO parameters. The identification of Rz as the most representative parameter across various laser settings addresses a clear gap in the current literature. The work is technically sound and methodologically rigorous, supported by an impressive dataset. The manuscript is interesting and presents a novel approach to evaluating surface roughness in laser-engraved wood. However, some parts need clarification and better structure. The topic is novel and directly applicable to both research and industrial settings. However, several areas—especially related to clarity, structure, and justification—require revision to enhance the manuscript's scientific impact and readability.

• Some phrasing is repetitive, it should be reconsidered,

Thank you for your comment. We have revised the text and deleted the sentences and/or paragraphs that were more repetitive. At the same time, we have tried to present the text in a way that is easier and simpler to read.

• Introduction, more detailed information should be provided on surface characterization.

In order to characterize the surface a new paragraph has been included in the introduction section, together with the references that support these new arguments.

“Characterizing surface roughness is a critical aspect in the industrial sector, as it directly impacts the quality and functionality of manufactured products. Surface roughness refers to the irregularities and variations present on a surface, which can affect properties such as friction, wear, adhesion, and aesthetic appearance [18]. “

• In the discussion section, not only the repetition of the results but also the literature comparison and potential applications could be more emphasized.

Two new sentences has been included in the discussion section.

“The identification of an ISO parameter that is sufficiently effective for quantitative assessment of roughness facilitates the integration of this procedure into a quality control process using standard roughness measuring equipment in the industry.”

“With this work, we propose a simple and efficient method for quantitatively comparing engraving results”.

The study has high potential and is suitable for publication after substantial revision.

Reviewer 3 Report

Comments and Suggestions for Authors

1. Please write the abstract into a single paragraph. The main findings of the study are not clearly mentioned in the abstract.

1. Bulk citations reflect non-comprehensiveness in the literature review. Please revise and avoid bulk citations [1-9]. Only cite the previous highly related works.

3. Missing citation from [13] to [29], in line#39 and line#42. The literature is not comprehensive enough to reflect the study of wood engraving. This part needs to be improved in terms of surface texture and laser engraving.
4. Please avoid one sentence in 1 paragraph, such as lines#53-57.
5. The accuracy of equipment is not provided in section 2.1.
6. The schematic diagram for the roughness measuring system and Vision Machine is not provided, as presented in Figures 3 and 4. Labels are needed to tell the reader about the equipment used.
7. Please check the figure numbering error, such as Figures 10 and 11 continue after Figure 4 (line#90). Also, there is a citation error for Figure 9 (line#148).
8. Figure 8 is not cited in the text, and the setting needs to be explained clearly.
9. Error bars are not included in the measurement data in Figures 15-17.
10. The discussion lacks connection with the previous works. For example, what comparing the current result with previous works.

Author Response

Dear Reviewer,

 

First of all, we would like to thank you for your comments and suggestions on our work. Undoubtedly, all of them have allowed us to think about it, see it from a different point of view, and complete and improve it to its current version.

 

We will now answer each of your questions. We hope that our answers will meet your expectations.

 

Thank you very much in advance.

The authors

Comments and Suggestions for Authors

1.- Please write the abstract into a single paragraph. The main findings of the study are not clearly mentioned in the abstract.

Thank you for your comment. Based on it, we have written the abstract in a single paragraph in which we have included the main findings of the study.

2.- Bulk citations reflect non-comprehensiveness in the literature review. Please revise and void bulk citations [1-9]. Only cite the previous highly related works.

A new sentence is included

“In this paper the Rz parameter is propose as the quantitative parameter to characterize the engraving”.

In addition, we have expanded and restructured the references to include the most up to date references on the subject.

3.- Missing citation from [13] to [29], in line#39 and line#42. The literature is not comprehensive enough to reflect the study of wood engraving. This part needs to be improved in terms of surface texture and laser engraving.

We agreed the reviewer comment. For this reason, we have put he missing citations and, in addition, such as we have said in the comment above, we have revised and updated the bibliographical references.

Besides, a new sentence has been included to clarify why ISO standards are used:

The ISO standardization is referenced because measuring roughness instruments evaluate these parameters by default. Before developing a new algorithm for measurement, this research investigated whether any of the ISO standard parameters were sufficiently suitable for characterizing bamboo engraving.

4.- Please avoid one sentence in 1 paragraph, such as lines#53-57.

We agreed the reviewer comment.  Therefore, we have deleted this sentence

5.- The accuracy of equipment is not provided in section 2.1.

We agreed the reviewer comment. It was given in table 4. We include it also in section 2.1 with this sentence:

The calibrated vision machine, at the time of measurement, achieved an uncertainty of 5 nm (k=1) with 500 degrees of freedom (see table 4).

6.- The schematic diagram for the roughness measuring system and Vision Machine is not provided, as presented in Figures 3 and 4. Labels are needed to tell the reader about the equipment used.

We agreed the reviewer comment. Labels have been included in Figures 3 and 4 to enhance readability.

Together with this, some of the figures has been enlarge in order to enhance them also.

7.- Please check the figure numbering error, such as Figures 10 and 11 continue after Figure 4 (line#90). Also, there is a citation error for Figure 9 (line#148).

We agreed the reviewer comment, it was not clearly written. The sentence has been improved to:

“The vision machine (figure 4) provided the detailed photos shown in Figures 10 and 11.”

8.- Figure 8 is not cited in the text, and the setting needs to be explained clearly.

We agreed the reviewer comment. It was included in the text as follows:

The parameters used in the engraving procedure are described in Table 1 and specifically recorded in the final compilation of the measurements developed for this research.

9.- Error bars are not included in the measurement data in Figures 15-17.

We agreed the reviewer comment. They were not included because the value of the uncertainty (specified in the figure title) is 0.5 µm, which is 100 times smaller than the smallest vertical division, making it indistinguishable in the plot. Nevertheless, its value is written below the figure.

10.- The discussion lacks connection with the previous works. For example, what comparing the current result with previous works.

In previous works, the research typically focused on the engraving process itself, rather than identifying which parameter might be useful for qualifying future engravings. The main contribution of our work is the proposal of a universal parameter for characterizing engraving across different materials, which is sensitive enough to improve the results.

Given the significance of this finding, we have emphasized it in the discussion section, with the above paragraph.