Review Reports - The Fundamental Mechanisms of Laser Cleaning Technology and Its Typical Applications in Industry

Round 1

Reviewer 1 Report

1)The paper should provide the development trend and existing problems of laser cleaning;

2)How to apply laser cleaning to materials with weak laser absorption?

3)Does laser polishing belong to laser cleaning?

4)The corresponding formulas for laser cleaning mechanism are provided in the article. Please provide examples to verify or apply these formulas.

5)There are individual writing errors in the main text and references of the paper.

I recommend that you enlist the aid of a native English speaker to help you improve the text.

Author Response

Question 1 (Q1): The paper should provide the development trend and existing problems of laser cleaning;

Answer 1 (A1): Thanks for your suggestions for improvement of our manuscript. This paper mainly introduce the fundamental mechanisms and related typical industry application in laser cleaning technology, so the introduction about development trend and existing problems of laser cleaning is rare in relative.

Q2: How to apply laser cleaning to materials with weak laser absorption?

A2: Thanks for your suggestions for improvement of our manuscript. When with weak laser absorption, we should increase the laser power or decrease the scanning speed.

Q3: Does laser polishing belong to laser cleaning?

A3: Thanks for your suggestions for improvement of our manuscript. The laser polishing doesn't belong to laser cleaning. Laser polishing process enables the smoothing of initial topography based on melting material by laser. Relative studies mainly focus on surface roughness and aim to better change the surface shape of substrate material. While the laser cleaning focus on attachments removal on substrate. In our manuscript, many references emphasize on the degree of laser cleaning damage or claim that the laser cleaning is a damage-free process. It means any change of substrate material in the process of laser cleaning should be reduced as much as possible. The change of surface roughness in laser cleaning is incidental, cause the surface micro-melting can not be avoided. And the effect of the roughness change may be positive or negative, which is completely different from the laser polishing requirement of improving the surface roughness.

Q4: The corresponding formulas for laser cleaning mechanism are provided in the article. Please provide examples to verify or apply these formulas.

A4: Thanks for your suggestions for improvement of our manuscript. Relative examples have been provided in this revised manuscript.

Q5: There are individual writing errors in the main text and references of the paper.

A5: Thanks for your suggestions for improvement of our manuscript. We have carefully checked the writing errors in the main text and references, and the revised parts were marked in red in this revised manuscript.

Reviewer 2 Report

1.The author's claim that "This work will provide very important reference value and guiding significance for researchers" may be overly absolute. It is recommended that the author modify this statement.

2.When describing the plasma shock wave effect, the author mentions that "The laser beam is parallel to the surface of the substrate rather than irradiate the surface of the substrate directly." However, in some research on laser plasma shock wave effects, the laser is incident perpendicular to the surface of the material. It is suggested that the author refer to relevant literature to elaborate on this part of the content.

English needs to be properly polished.

Author Response

Q1: The author's claim that "This work will provide very important reference value and guiding significance for researchers" may be overly absolute. It is recommended that the author modify this statement.

A1: Thanks for your suggestions for improvement of our manuscript. We have modified this statement.

Q2: When describing the plasma shock wave effect, the author mentions that "The laser beam is parallel to the surface of the substrate rather than irradiate the surface of the substrate directly." However, in some research on laser plasma shock wave effects, the laser is incident perpendicular to the surface of the material. It is suggested that the author refer to relevant literature to elaborate on this part of the content.

A2: Thanks for your suggestions for improvement of our manuscript. We have read the related literature to improve our revised manuscript.

Reviewer 3 Report

The author presented laser cleaning mechanism and summarized its applications for metal, non-metal, and semiconductor. I believe that the below should be revised for a publication.

1. The environmental issues for common surface cleaning technique should be presented in Introduction, because one of the advantages of the laser cleaning technique is eco-friendly.

2. Correct the typo in line 169 (σp)

3. In figure 3, the plasma and surface distance is 3 mm, and this value is quite large. Please double check this value.

4. The shorter laser pulse width not always guarantee the laser efficiency (line 242) because laser cleaning time may increase with a shorter laser pulse width.

5. In line 271, there is double space. “So the laser can not cause ther”

6. The paint removal should be included in “3.1. Metallic material” because it is a major field of surface cleaning

7. The readility is pretty low. Please add sub-categories such as 3.1.1 Oxide

8. The author should link the laser cleaning mechanism with their applications at least 2~3 cases. There is no relation between “2. Laser cleaning mechanism” and “3. Typical applications of laser cleaning in industrial fields”.

Should correct minor errors.

Author Response

The author presented laser cleaning mechanism and summarized its applications for metal, non-metal, and semiconductor. I believe that the below should be revised for a publication.

Q1: The environmental issues for common surface cleaning technique should be presented in Introduction, because one of the advantages of the laser cleaning technique is eco-friendly.

A1: Thanks for your suggestions for improvement of our manuscript. The environmental issues for common surface cleaning techniques were added in the Introduction. And the revised parts were marked in red.

Q2: Correct the typo in line 169 (σp)

A2: Thanks for your suggestions for improvement of our manuscript. The typo in line 169 has been corrected.

Q3: In figure 3, the plasma and surface distance is 3 mm, and this value is quite large. Please double check this value.

A3: Thanks for your suggestions for improvement of our manuscript. We have check the value between plasma and the surface, the correct value is 3 mm.

Q4: The shorter laser pulse width not always guarantee the laser efficiency (line 242) because laser cleaning time may increase with a shorter laser pulse width.

A4: Thanks for your suggestions for improvement of our manuscript. We have modified this statement in this revised manuscript.

Q5: In line 271, there is double space. “So the laser can not cause ther”

A5: Thanks for your suggestions for improvement of our manuscript. The problems about space has been solved.

Q6: The paint removal should be included in “3.1. Metallic material” because it is a major field of surface cleaning

A6: Thanks for your suggestions for improvement of our manuscript. We have taken paint removal into consideration and provide some examples in this revised manuscript.

Q7: The readility is pretty low. Please add sub-categories such as 3.1.1 Oxide

A7: Thanks for your suggestions for improvement of our manuscript. We have increased the sub-categories in section 3.1.

Q8: The author should link the laser cleaning mechanism with their applications at least 2~3 cases. There is no relation between “2. Laser cleaning mechanism” and “3. Typical applications of laser cleaning in industrial fields”.

A8: Thanks for your suggestions for improvement of our manuscript. At the end of section 2, we have briefly expounded the scope of cleaning applications of each mechanism. And We have added relative mechanism of some specific examples in section 3.

Reviewer 4 Report

DEAR AUTHORS: Laser cleaning has a complex process mechanism and some times these mechanisms interfere with each other, so regarding your manuscript, some main issues should be considered:

1- I highly recommended that the authors examining a book chapter of laser cleaning by William M.Steen and Jyotirmoy Mazumder , the book is Laser Material Processing 2010. This chapter give a full details of laser cleaning mechanisms and the overlap between these mechanisms, also it give a very important relation between the intensity of the laser beam and the interaction time which can provide a very important information about the mechanism type used during laser cleaning process. Please consider these information in your manuscript.

2- The authors did not mention the types of laser systems that are used in laser cleaning , this is a review paper and should include these information and details of laser types like CO₂ laser ,Nd:YAG laser, Fiber laser and so on that are widely used in laser cleaning process.

3- There are some sentences that are repeated in the abstract and in the introduction and conclusion part, please correct and rewrite.

4- In introduction part there is some dates that are not coincide with the reference (example: line 63 page 2 , {In 1995 and the ref is 1994}).

5- Please check equation 1 in page 3, is it correct???

6- After the authors make all the corrections the conclusion part should be updated.

There are some issues about language and grammar. Suggest that it be checked and improved or corrected.

Author Response

DEAR AUTHORS: Laser cleaning has a complex process mechanism and some times these mechanisms interfere with each other, so regarding your manuscript, some main issues should be considered:

Q1: I highly recommended that the authors examining a book chapter of laser cleaning by William M.Steen and Jyotirmoy Mazumder , the book is Laser Material Processing 2010. This chapter give a full details of laser cleaning mechanisms and the overlap between these mechanisms, also it give a very important relation between the intensity of the laser beam and the interaction time which can provide a very important information about the mechanism type used during laser cleaning process. Please consider these information in your manuscript.

A1: Thanks for your suggestions for improvement of our manuscript. The recommended book is well to help us to learn about the laser cleaning mechanism, and we have added this book as a reference in this revised manuscript.

Q2: The authors did not mention the types of laser systems that are used in laser cleaning , this is a review paper and should include these information and details of laser types like CO2 laser ,Nd:YAG laser, Fiber laser and so on that are widely used in laser cleaning process.

A2: Thanks for your suggestions for improvement of our manuscript. The information and detail of laser system and laser parameters were added in this revised manuscript.

Q3: There are some sentences that are repeated in the abstract and in the introduction and conclusion part, please correct and rewrite.

A3: Thanks for your suggestions for improvement of our manuscript. We have rewrote the repeated parts, and the revised parts were marked in red in this manuscript.

Q4: In introduction part there is some dates that are not coincide with the reference (example: line 63 page 2 , {In 1995 and the ref is 1994}).

A4: Thanks for your suggestions for improvement of our manuscript. The correct year is 1995, and we have changed it in our revised manuscript.

Q5: Please check equation 1 in page 3, is it correct???

A5: Thanks for your suggestions for improvement of our manuscript. The equation is correct, which can be seen in page 341 in the ref.24.

Q6: After the authors make all the corrections the conclusion part should be updated.

A6: Thanks for your advice, the conclusion part has been updated in this revised manuscript, and the revised parts were marked in red.

Round 2

Reviewer 1 Report

he revised version shows obvious improvement over the original version. The authors' responses to the reviewers' comments are satisfactory.

Author Response

Thanks for your suggestions for improvement of our manuscript.

Reviewer 2 Report

The author has revised the paper according to the revision comments. The quality of the paper has been further improved. It is suggested to publish the revised paper.

English language fine.

Author Response

Thanks for your suggestions for improvement of our manuscript.

Reviewer 3 Report

The authors well delivered my comments. Now, the manuscript can be accepted.

Minor errors should be revised.

Author Response

Thanks for your suggestions for improvement of our manuscript.

Reviewer 4 Report

DEAR AUTHORS:

Thanks a lot for your efforts regarding the improvements of your manuscript, still i will repeat my first note in my previous review:

The note above is not only to be consider it as a reference but to include the information about laser cleaning mechanisms and the overlap between them in your manuscript, also to explain the relation between the the laser light intensity and the interaction time during the process (a figure explain this relation can be included).

Author Response

Thanks a lot for your efforts regarding the improvements of your manuscript, still I will repeat my first note in my previous review:

Question: I highly recommended that the authors examining a book chapter of laser cleaning by William M.Steen and Jyotirmoy Mazumder , the book is Laser Material Processing 2010. This chapter give a full details of laser cleaning mechanisms and the overlap between these mechanisms, also it give a very important relation between the intensity of the laser beam and the interaction time which can provide a very important information about the mechanism type used during laser cleaning process. Please consider these information in your manuscript. The note above is not only to be consider it as a reference but to include the information about laser cleaning mechanisms and the overlap between them in your manuscript, also to explain the relation between the laser light intensity and the interaction time during the process (a figure explain this relation can be included).

Answer: Thanks for your suggestions for improvement of our manuscript. We have included information about the overlap of laser cleaning mechanisms. We have also appended a figure which explain the relation between the laser light intensity and the interaction time during the laser cleaning process.