Can Plasma Surface Treatment Replace Traditional Wood Modification Methods?

Round 1

Reviewer 1 Report

„Can Plasma Surface Treatment Replace Traditional Wood Modification Methods?” attempts to convince readers about the advantage of plasma treatment over other wood modification/treatment methods. I find the idea interesting. However, the manuscript does not meet the requirements of the review paper – most statements are vague, based just on one reference (frequently other review papers, and not the results of original research). Some information is incomplete, vague or even untrue. I stopped reviewing the paper on paragraph 2.2, because I had the same comments repeatedly (they can be found in the pdf file attached). I recommend rejection of the paper and resubmission after thorough corrections and supplementations with all scientific details (and relevant references) necessary to present a proper state of the art in the area of wood modification.

Comments for author File: Comments.pdf

Author Response

Answers for Reviewer 1:

While we appreciate that the reviewer is always right, we have no choice but to regard this reviewer opinion as seriously questionable. Being regular peer reviewers ourselves, we always honour the authors by reading through the whole article to the end, even if the decision is rejection, and expect the same level of correctness and scrutiny from the reviewers who judge our work. Our manuscript contains 22 pages and the reviewer read 2 of them and wrote that “The same comment relates to the whole manuscript”. We can fully accept that there are mistakes in the article, but this review provides vague and unhelpful criticism rather than pointing out specific issues to improve upon. Nonetheless, we did improve our paper based on the feedback that we could actually utilize, and kindly ask the editor to reconsider whether this reviewer opinion is at a sufficient level to justify the rejection of our manuscript.

„Can Plasma Surface Treatment Replace Traditional Wood Modification Methods?” attempts to convince readers about the advantage of plasma treatment over other wood modification/treatment methods. I find the idea interesting. However, the manuscript does not meet the requirements of the review paper – most statements are vague, based just on one reference (frequently other review papers, and not the results of original research). Some information is incomplete, vague or even untrue. I stopped reviewing the paper on paragraph 2.2, because I had the same comments repeatedly (they can be found in the pdf file attached). I recommend rejection of the paper and resubmission after thorough corrections and supplementations with all scientific details (and relevant references) necessary to present a proper state of the art in the area of wood modification.

Answer: We regret very much that the reviewer did not find the work worth reading to the end. Some of his/her questions/remarks are answered in the rest part of the manuscript. The basic motivation of our MS was to introduce the effectiveness of industrially feasible cold plasma techniques in terms of surface modification of wood, which is a relatively new method compared to other traditional ones. It was beyond the scope of the current MS to show all wood modification techniques with full details. So we thought (and still think) it would be more beneficial to refer review articles or books on these topics and readers could choose the most appropriate for his/her studies than show 2 or 3 original papers. In the presentation of plasma surface treatments, we certainly introduced the results of the original articles.

1. But only in the meaning of adding chemicals to it and creating new bonds between some of wood polymers and the chemicals - the methods in general do not change the amount or ratio of individual wood polymers - please rephrase the sentence to make it clear.

Answer: Not all, but most of the methods change the composition of wood. The active wood modification techniques change the composition of wood in all cases but our sentence was not correct, indeed, so we have amended it. Thank you for bringing it to our attention.

2. The question is what was the purpose of modification - it some cases surface modification is not enough (e.g. coatings are not effective for wood protection against fungal degradation - cracks in coatings do not prevent moisture and fungi to penetrate wood tissue) - please rephrase the sentence.

Answer: Thank you for sharing your opinion with which we fully agree and accept and the answers are in paragraph 2.5 Efficiency and environmental impact of methods and 5. Summary, in the original manuscript. We could not go into details because of the word limitation of the abstract.

3. 3. Please divide introduction into smaller paragraps according to the rule "one idea per paragraph".

Answer: We did paragraphs according to the “rule”.

4. Not all modification treatments are harmful to the environment - to make it clear, please give here some examples of environmentally-friendly and not environmentally-friendly methods.

Answer: Environmentally-friendly or not it's all a matter of perspective. In the authors opinion all chemical modifications are a burden on the environment, if only for the energy and water they consume. Using plasma means minimising these, which is why we consider it as a green technology. Apart from plasma treatment, it is difficult, if not impossible, to find an environmentally-friendly technology.

5. 5. This statement is too broad, too vague - please give some examples - how some selected individual treatments influence wood properties.

Answer: Yes, the reviewer is right, it is too broad, but the authors go into details in later in the original manuscript. 111-113 rows. But for alkali modification, we inserted a new reference that which describes the controversial explanation in literature about changes of mechanical properties and show their own results as well.

Bartos András, Anggono Juliana, Farkas Ágnes Elvira, Kun Dávid, Soetaredjo Felycia Edi, Móczó János, Antoni ., Purwaningsih Hariyati, Pukánszky Béla:Alkali treatment of lignocellulosic fibers extracted from sugarcane bagasse: Composition, structure, properties, POLYMER TESTING 88 Paper: 106549 (2020)

6. 6. These are not proper references to discuss pros and cons of wood modification methds - please provide more relevant references.

Answer: We put more references, but leave the original ones too because we found useful details in them.

7. 7. Please provide some examples of green technologies in wood modification that replace those harmful old ones (name both of them - which of them has replaced which).

Answer: The title of the manuscript is that can replace or not and the conclusion is in the original manuscript, that cannot. It can be found in Summary.

8. Please give examples from the industry plus references.

Answer: We put some references.

9. Please provide research articles as references to this statement - writing a review paper based on other review papers is not fully appropriate - citing the results of direct studies is more justified and scientifically sound.

Answer: The proper introduction of plasmas and plasma treatments is not the scope of this manuscript. What we really want to introduce is the possibility of plasma treatment on the field of wood modification. The relevant references for this purpose are in the following chapters.

10. 10. Please provide the aim and purpose of the article.

Answer: Thank you for noticing this sentence, we corrected for clarity.

11. 11. I suggest to provide scientific definitions for all tpes of wood treatment used in the manuscript, confirmed with relevant references, to clarify these issues.

Answer: We did not want to give the exact definitions of the traditional treatments, because everyone has a different definition, depending on who the author is. In the given review article or books, readers can find the possibilities for definition. The most commonly used definitions are in Hill's book, which is included in the reference list. (Hill, C.A.S. Wood Modification: Chemical, Thermal and Other Processes)

12. The paragraph seems a bit chaotic - please divide it into shorter parts and keep one idea per paragraph.

Answer: We are sorry if it seems a bit chaotic so we divided it into shorter parts.

13. 13. Please provide more references for this statement.

Answer: We did.

14. 14. Please provide the examples of the properties that can be improved by changing the genetics of the tree, with relevant references.

Answer: We rewrite the sentences for clarity.

15. 15. What is this example of? Of changing the tree genetics? Please clarify and provide references.

Answer: Recent advances in tree genetics (modifying the lignin biosynthesis gene) permit lignin content and structure modification in different plants. Lower lignin content will reduce the cost of the extraction of cellulose from the plants. We inserted the relevant reference which is a review article too, but most genetic manipulation can be found in it.

16. Again, give some examples with references to justify the statement.

Answer: We inserted relevant references.

17. Impregnation is a common method - please provide more details and references, to present the complete state of the art in this area.

Answer: I understand the reviewer's point that it would be nice to explain everything, but simply can't fit everything he/she asks for into one article. But the complete state of the art of impregnation fills a book, not a chapter in an article.

18. What do the authors mean by "conserving the properties of wood"? Please clarify. And provide the reasons for wood modification, with relevant references.

Answer: Chemical composition, dimension, sometimes colour. We have corrected the sentence.

19. If impregnation is to "fill the cell walls and lumen" - how coating could be the impregnation? Please correct the statement and provide suitbale references.

Answer: According to the authors, the coating is the impregnation of the surface. There may not be any literature that describes it this way, but to the best of our knowledge, we think so. We hope we can afford to include some of our thoughts/ideas in our manuscript.

20. Please provide more scientifically-based information confirmed with suitbale references.

Answer: Thank you for noticing the missing reference. The findings are based on the following book: Bulian, F.; Graystone, J. Wood coatings : theory and practice; Elsevier Science, 2009;

21. One cannot rely only on other review articles writing a new revie paper. Please provide more detailed information about wood thermal modification along with relevant references that describe research in this area.

Answer: We still believe that a detailed description of all kind of modification technique what the reviewer is asking for is beyond the scope of the current MS.

Reviewer 2 Report

Dear Authors,

I have read the article entitled „ Can Plasma Surface Treatment Replace Traditional Wood Modification Methods?".

This study presents a review of traditional wood modification methods along with plasma treatments and shows their advantages and disadvantages as well. The subject falls within the scope of the Journal.

The title and abstract reflect the content. The introduction initiates the reader on the subject. The manuscript has well-prepared content. A very well-selected list of references was used.

I have a few observations. Along the text, I found several paragraphs that need a little improvement:

Page 4 lines 144-145: Please, fix the sentence (“by”)

Page 5 lines 197-200: Please, fix and split the paragraph

Page 7 lines 292-293: Please, fix the sentence

Page 7 lines 295-298: Please, split the text

Page 9 lines: 363-367: the text is too long, please split it

Page 11 lines 444-445: …is to be….give short comments on grafting here

Page 11 lines 448-450: Please, fix the sentence

Page 11 line 468:……can seriously affect all components

Page 12 lines 475-478 and 478-481: it is difficult to follow, please fix and split

Once these are fixed the paper is ready for publication.

I hope my revision was of help.

Author Response

We really appreciate your comments and critical remarks, by which we could hopefully improve our manuscript. We have now corrected our original manuscript. All changes are indicated by using “track changes” option in order to identify the new corrections. We hope that the changes we have made will fully satisfy your expectation.

Dear Authors,

I have read the article entitled „ Can Plasma Surface Treatment Replace Traditional Wood Modification Methods?".

This study presents a review of traditional wood modification methods along with plasma treatments and shows their advantages and disadvantages as well. The subject falls within the scope of the Journal.

The title and abstract reflect the content. The introduction initiates the reader on the subject. The manuscript has well-prepared content. A very well-selected list of references was used.

I have a few observations. Along the text, I found several paragraphs that need a little improvement:

Answer: We appreciate very much your effort what introduced into the evaluation of our manuscript and especially your valuable suggestions for the improvement of this work.

Page 4 lines 144-145: Please, fix the sentence (“by”)

Page 5 lines 197-200: Please, fix and split the paragraph

Page 7 lines 292-293: Please, fix the sentence

Page 7 lines 295-298: Please, split the text

Page 9 lines: 363-367: the text is too long, please split it

Page 11 lines 444-445: …is to be….give short comments on grafting here

Page 11 lines 448-450: Please, fix the sentence

Page 11 line 468:……can seriously affect all components

Page 12 lines 475-478 and 478-481: it is difficult to follow, please fix and split

Once these are fixed the paper is ready for publication.

I hope my revision was of help.

Answer: We corrected all of them and indicated in the MS.

Reviewer 3 Report

Review of the article: Can Plasma Surface Treatment Replace Traditional Wood Modification Methods?

The topic of this research and output might be useful for the Coatings readers. The conducted work is worth to publish, however in order to improve the manuscript the following suggestions should be considered.

 Abstract:

Line 12: In two sentences, it is necessary to clarify what types of modifications are taken into account in this case: thermal, chemical, thermo-mechanical or other.

Lines 16-17: Although these methods achieve the desired properties, they require a lot of energy and chemicals…

§  This is too general a statement and is misleading. All methods or only selected methods require a lot of energy and chemicals… 

 Introduction

2. Modification of wood – traditional methods

Justify why these methods have been chosen and described. There are also other methods, such as thermo-mechanical modification, carried out on a laboratory and industrial scale; eg. literature:

§  Bekhta, P.; Salca, E.A.; Lunguleasa, A. Some properties of plywood panels manufactured from combinations of thermally densified and non-densified veneers of different thicknesses in one structure. J Build Eng 2020, 29, 101116; DOI: 10.1016/j.jobe.2019.101116.

§  Laskowska, A.; Sobczak, J.W. Surface chemical composition and roughness as factors affecting the wettability of thermo-mechanically modified oak (Quercus robur L.). Holzforschung 2018, 72(11), 993-1000; DOI: 10.1515/hf-2018-0022.

§  Antikainen, T.; Paajanen, O.; Rautkari, L.; Kutnar, A.; Kamke, F.A.; Hughes, M. Simultaneous dryling and densification of silver birch (Betula pendula L.) veneers: analysis of morphology, thickness swelling, and density profile. Wood Sci Technol 2014, 48, 325-336; DOI: 10.1007/s00226-013-0605-0. 

2.2. Thermal modification

Line 97: The citation number should be after the author and not at the end of the sentence. 

2.4. Chemical modification

Lines 153 – 155: Why is this figure given here since it concerns many methods and not the chemical method? This is a very illustrative drawing. If it is, it should be placed after the paragraph 56-71.

2.5. Efficiency and environmental impact of methods

Lines 159-167: These are very general data. Please develop them, indicate, for example, what substances and what they can have a harmful effect on. 

3.1. Plasma

Lines 208-209: Is this the justification for the article? Please refer to the indicated article. But this is not the reason why you should only briefly present/summarize the issues. Please correct this entry. 

3.2. Plasma surface interaction

Line 292: As mentioned earlier…§  Which sentence does this phrase refer to? The phrase (As mentioned earlier) should also be removed in order to avoid any understatements.

Figure 3: This figure is redundant as it is simple in pronunciation and the data can be included in the text. Moreover, the figure shows that during the modification we deal only with round wood. Is it really? 

Line 310: This underlies the article and should be included and developed in a paragraph at the very beginning of the article. In the introduction, the purpose of the article should be outlined, including, among others, this statement. 

3.3.1. XPS, FTIR

Line 394: Be consistent and indicate the full name of the test method first, followed by the abbreviation. 

In the description of the traditional and plasma methods, there is no information about the modification conditions, the most frequently used parameters. Please, if possible, complete this data. This will certainly increase the value of the article and affect its citation.

Comments for author File: Comments.pdf

Author Response

We really appreciate your comments and critical remarks, by which we could hopefully improve our manuscript. We have now corrected our original manuscript. All changes are indicated by using “track changes” option in order to identify the new corrections. We hope that the changes we have made will fully satisfy your expectation.

The topic of this research and output might be useful for the Coatings readers. The conducted work is worth to publish, however in order to improve the manuscript the following suggestions should be considered.

 Abstract:

Line 12: In two sentences, it is necessary to clarify what types of modifications are taken into account in this case: thermal, chemical, thermo-mechanical or other.

Lines 16-17: Although these methods achieve the desired properties, they require a lot of energy and chemicals…

• This is too general a statement and is misleading. All methods or only selected methods require a lot of energy and chemicals…

Answer: Reviewer is absolutely right. We made some modification on these sentences to improve the correctness of the sentences and make it easier to comprehend.

 Introduction

2. Modification of wood – traditional methods

Justify why these methods have been chosen and described. There are also other methods, such as thermo-mechanical modification, carried out on a laboratory and industrial scale; eg. literature:

• Bekhta, P.; Salca, E.A.; Lunguleasa, A. Some properties of plywood panels manufactured from combinations of thermally densified and non-densified veneers of different thicknesses in one structure. J Build Eng2020, 29, 101116; DOI: 10.1016/j.jobe.2019.101116.
• Laskowska, A.; Sobczak, J.W. Surface chemical composition and roughness as factors affecting the wettability of thermo-mechanically modified oak (Quercus roburL.). Holzforschung 2018, 72(11), 993-1000; DOI: 10.1515/hf-2018-0022.
• Antikainen, T.; Paajanen, O.; Rautkari, L.; Kutnar, A.; Kamke, F.A.; Hughes, M. Simultaneous dryling and densification of silver birch (Betula pendulaL.) veneers: analysis of morphology, thickness swelling, and density profile. Wood Sci Technol 2014, 48, 325-336; DOI: 10.1007/s00226-013-0605-0. 

Answer: Thanks for your comment. We made our classification according to the basic book about this topic, C.A.S., Hill: Wood Modification Chemical, Thermal and Other Processes where, these types have been emphasised. Certainly, there are more methods, but perhaps all of them can fit any of the “main” classifications. Thermo-mechanical modification is a thermal modification, and we could indeed have given to it more attention, so we would insert into the manuscript with the references.

2.2. Thermal modification

Line 97: The citation number should be after the author and not at the end of the sentence. 

Answer: Thanks for your noticing, we corrected.

2.4. Chemical modification

Lines 153 – 155: Why is this figure given here since it concerns many methods and not the chemical method? This is a very illustrative drawing. If it is, it should be placed after the paragraph 56-71.

Answer: In this drawing, each traditional method is presented, including chemical one. (It is on the left side.) If the reviewer don’t mind, we would leave it at the original place because it was a summary of the methods described earlier.

2.5. Efficiency and environmental impact of methods

Lines 159-167: These are very general data. Please develop them, indicate, for example, what substances and what they can have a harmful effect on. 

Answer: We have added some details

3.1. Plasma

Lines 208-209: Is this the justification for the article? Please refer to the indicated article. But this is not the reason why you should only briefly present/summarize the issues. Please correct this entry. 

Answer: Paragraph was rephrased/rearranged.

3.2. Plasma surface interaction

Line 292: As mentioned earlier…§  Which sentence does this phrase refer to? The phrase (As mentioned earlier) should also be removed in order to avoid any understatements.

Answer: We removed the phrase.

Figure 3: This figure is redundant as it is simple in pronunciation and the data can be included in the text. Moreover, the figure shows that during the modification we deal only with round wood. Is it really? 

Answer: We removed the figure from the manuscript.

Line 310: This underlies the article and should be included and developed in a paragraph at the very beginning of the article. In the introduction, the purpose of the article should be outlined, including, among others, this statement. 

Answer: Thank you for noticing this sentence. Reviewer is right we wrote a sentence into the introduction part for clarity.

3.3.1. XPS, FTIR

Line 394: Be consistent and indicate the full name of the test method first, followed by the abbreviation. 

Answer: We corrected as requested.

In the description of the traditional and plasma methods, there is no information about the modification conditions, the most frequently used parameters. Please, if possible, complete this data. This will certainly increase the value of the article and affect its citation.

Answer: Thank you for the suggestion, but we are afraid it may be difficult to implement. The modification condition is always different in all cases there are a lot of them especially in case of traditional methods. We can change many parameters in a given plasma setup. Plasma power, treatment duration, electrode gap, distance between electrode and surface, plasma gas or in a low pressure plasma even the pressure is a variable parameter. There's an entire spectrum of possibilities. In addition, the design of the plasma can be very different even for the same operating principle. In most cases, the researchers prepare one in laboratory scale and try to set up the ideal conditions, and if they succeed, the structure may be developed further industrial application. If the reviewer really feels that to collect these very different plasma parameters will improve our manuscript, we can make a summary table, but that will take more time than we have been given for the correction.

Once more, we would like to thank for your valuable remarks and suggestion which undoubtedly enhances the scientific value of our manuscript.

Reviewer 4 Report

The review paper is well written and compiles the information of plasma treatment  on wood.  Some minor corrections have been provided and may be included. As it is a review paper and the research results of earlier authors are being presented, it is important to cite the reference as per the journal guidelines or accepted formats.  

Comments for author File: Comments.pdf

Author Response

Thank you very much your comments and critical remarks, by which we could hopefully improve our manuscript. We have now corrected our original manuscript. All changes are indicated by using “track changes” option. We hope that the changes we have made will fully satisfy your expectation.

Round 2

Reviewer 1 Report

I do not find the corrections made in the manuscript enough to recommend the paper for publishing.

Reviewer 3 Report

Thank you for entering your comments.

The article contains the necessary corrections, although the analyzed research methods could be presented in more detail (record of process parameters).