Effect of Acetylation on the Physical and Mechanical Performances of Mechanical Densified Spruce Wood
Round 1
Reviewer 1 Report
1. Please increase some reference
2. Latest references (2022 and 2021) totally 6 out of 25. So, try to add more latest references.
3. Can include numerical value in conclusion.
4. Can elaborate more about the microstructure variation with respect to the load withstanding ability during treatment.
5. Internal atomic changes during the compression can be explained little more.
Author Response
Thank you so much for all suggestions. The responses as following:
Comments and Suggestions for Authors
- Please increase some reference
Response: The references have been added to support our study.
- Latest references (2022 and 2021) totally 6 out of 25. So, try to add more latest references.
Response: The references have been refreshed.
- Can include numerical value in conclusion.
Response: The conclusion has been improved.
- Can elaborate more about the microstructure variation with respect to the load withstanding ability during treatment.
Response: The related discussion has been added in line 217-218.
- Internal atomic changes during the compression can be explained little more.
Response: The related discussion has been added in line 221-223.
Author Response File: 
Author Response.doc
Reviewer 2 Report
The manuscript “Effect of Acetylation on the Physical and Mechanical Performance of Mechanical Densified Spruce Wood” describes the effect of combined acetylation and densification treatment on the selected properties of spruce wood.
The study is important, and the results are interesting and potentially applicable in the wood industry. However, I have some doubts about the planning of the experiment, especially about the anatomical directions of the wood samples used in the study. For this particular material, the properties are different and dependent on the directions, and it is pointless to compare the data if the samples are not identically and correctly oriented. Therefore, I suggest supplementing this essential information in the manuscript. Some more comments and suggestions can be found in the attached file.
Comments for author File: 
Comments.pdf
Author Response
Thank you so much for all suggestions. The responses as following:
In line 50, the word "been" is missing.
Response: It is now revised.
In lines 44-45, what is the advantage that emerges by the reduction of the volume of the wood cell cavity (explain to be clarified to the reader).
Response: This part has been revised to explain the wood densification.
Since the number of references used in the manuscript are quite low, I would recommend the authors to add also the significant and relevant work of DOI: 10.3390/polym12081638. Generally the description of state-of-the-art should be enriched to strengthen and provide to the readers a holistic view of the topic. In line 70, by saying that the reader understands that the previous studies used in the beginning the mechanical densification and secondly the acetylation (but is that true?). In my opinion, the significance of this work could be highlighted adequately by adding one or two phrases.
Response: The description of the wood densification has been enriched, especially the potential effect of acetylation on the densification. The Introduction has been revised to be more logical.
In materials-methods section, provide the latin name of the species used.
Response: It has been added.
Explain the term "tangential lumber" since it would be confusing to the reader.
Response: We revise it into “…compressed in radial direction”.
Which was the moisture content and density of wood specimens before the impregnation?
Response: The wood samples were oven-dried before acetylation. The average density is 0.45 g/cm3. All have been added in Materials and Methods.
In line 84, where are the specimens being immersed (specify).
Response: It has been revised.
Which are the details of the thermal compression machine used (manufacturer, model, country etc.)?
Response: It has been added.
Please, provide for each of the processes applied in the experimental work, the respective standards of the processes (for example in line 106).
Response: The standards or basis have been added.
In line 105 and 113, the phrase "thickness of compression thickness" needs improvement.
Response: It is now revised.
The statistical analysis of the results is not described at all in the text of materials-methods. Figures and tables in the text are really useful.
Response: The statistical analysis has been added.
The conclusions are well-prepared, though this chapter should be a little more specific concerning the findings of this experimental work.
Response: The conclusion has been revised. Some numerical values of the findings are added.
Author Response File: Author Response.doc
Reviewer 3 Report
The topic of the research work and manuscript is really interesting and provides new information. However there are some issues to be addressed towards its quality improvement before publication.
In line 50, the word "been" is missing. In lines 44-45, what is the advantage that emerges by the reduction of the volume of the wood cell cavity (explain to be clarified to the reader). Since the number of references used in the manuscript are quite low, I would recommend the authors to add also the significant and relevant work of DOI: 10.3390/polym12081638. Generally the description of state-of-the-art should be enriched to strengthen and provide to the readers a holistic view of the topic. In line 70, by saying that the reader understands that the previous studies used in the beginning the mechanical densification and secondly the acetylation (but is that true?). In my opinion, the significance of this work could be highlighted adequately by adding one or two phrases.
In materials-methods section, provide the latin name of the species used. Explain the term "tangential lumber" since it would be confusing to the reader. Which was the moisture content and density of wood specimens before the impregnation? In line 84, where are the specimens being immersed (specify). Which are the details of the thermal compression machine used (manufacturer, model, country etc.)? Please, provide for each of the processes applied in the experimental work, the respective standards of the processes (for example in line 106). In line 105 and 113, the phrase "thickness of compression thickness" needs improvement. The statistical analysis of the results is not described at all in the text of materials-methods. Figures and tables in the text are really useful. The conclusions are well-prepared, though this chapter should be a little more specific concerning the findings of this experimental work.
Author Response
Thank you so much for all suggestion. The response as following:
The manuscript “Effect of Acetylation on the Physical and Mechanical Performance of Mechanical Densified Spruce Wood” describes the effect of combined acetylation and densification treatment on the selected properties of spruce wood.
The study is important, and the results are interesting and potentially applicable in the wood industry. However, I have some doubts about the planning of the experiment, especially about the anatomical directions of the wood samples used in the study. For this particular material, the properties are different and dependent on the directions, and it is pointless to compare the data if the samples are not identically and correctly oriented. Therefore, I suggest supplementing this essential information in the manuscript. Some more comments and suggestions can be found in the attached file.
Response: Thanks for your comments. The bulk compression of wood in radial direction is a simple process. Due to the differences in density and structure, the interaction between earlywood and latewood is weak, resulting in severe separation during compression in tangential direction if no special mold used. The related experiments were carried out. However, the structure of the densified wood was damaged and dislocation. Therefore, we only use the data of compression in radial direction to analysis the effect of acetylation on the densification.
In Fig. 1, only densified wood samples were chosen with straight-grained structure. The control and acetylated wood samples were machined into small straight-grained samples for dimensional stability and mechanical properties tests.
All the issues are revised and highlighted with red color in the manuscript. The conclusion is rewritten.
Author Response File: Author Response.doc
Round 2
Reviewer 2 Report
The manuscript has been improved and supplemented.
Reviewer 3 Report
As I have checked the authors have implemented the proposed changes in the revised verion of manuscript towards the improvement of their work. Almost all the changes have been implemented and in my opinion, the manuscript is well-prepared and organized enough to be accepted for publication in this journal.
