Comparative Surface Quality of Maple (Acer pseudoplatanus) Cut through by CNC Routing and by CO₂ Laser at Different Angles as Related to the Wood Grain

Round 1

Reviewer 1 Report

I accepted the proposal for writing the review because the subject of the paper reviewed is within my own research area. At the first moment, I believed that elaborating the review for this paper would not generate any problems. It was true, until the chapter Material and Methods. To understand the methods and approaches described, I needed to re-read this section several times, and moreover to ask the cited reference [1]. The methods should always be explained in a way easy to understand by each reader, not only those working exactly in the area, and the experiments should be described in a way allowing to run replications, if necessary.

My recommendation to the methods:

1.      Figure 1 is of poor quality, without explanatory value. I propose to cancel it

2.      Figure 2 is of poor quality, too. It does not allow us to figure out either what milled surfaces were concerned, or the angles at which the surfaces were milled. The text is not explicit. I recommend substituting this figure with a schematic representation specifying the treated surface types and the fibre course in these surfaces.

3.      I am not certain with my idea whether or not the surfaces milled with a CNC equipment and a laser were in all cases radial, see my Fig. 1.app appended. The first specimen was cut in a way to obtain a declination of 0° from the longitudinal axis of the body (Fig. 1a). The following specimens represented the following fibre decline from the longitudinal axis: 15°, 30°, 45° (Fig. 1b), ... up to 90°, where the fibres were oriented perpendicular to the longitudinal axis (Fig. 1c). Figure1 shows that the related surface was always radial.

4.      If the roughness was measured always parallel to the specimen axis, then in the first case, the roughness profile was inspected parallel to the grain course, in the second case at a 45° angle to the grain course and in the third case perpendicular to the grain course. But then the statement in the line 378-9 „The 90° is a perfect crosscut when all anatomical cells show open lumens, which seem to be detected by micrographs (Figure  11m, n)...“ is incorrect. Also, there is no reason to provide pictures of cross-cuts. Or it is true that the treated surfaces were always cross-cuts? This fact needs clear specifications in the Methods.

5.      I do not know whether the dominant roughness parameter is Rk, nevertheless I also recommend as obligatory parameter Ra, to obtain a more comprehensive idea about the roughness patterns.

6.      These facts are necessary to comprise discussing the results, deriving conclusions and in the Abstract.

7.      Comment concerning the maple wood structure. Libriform fibres in maple wood exhibit the thinnest cell walls compared to the other broadleaved wood species (except for several poplar species). As much as 70 % of the fibre width is the lumen. The rather high maple wood density is due to a low fraction of vessels (app. 7 %). On the other hand, oak wood contains libriform fibres with the thickest call walls and with the narrowest lumina (only beech lumina are narrower and cell walls thicker). This is the main cause of the differences in roughness between the two species you compare.

8.      There were not treated edges but surfaces

9.      Figures 4 and 11 do not exhibit an appropriate quality. A proper distinction in depth is lacking.

10.  In Figures 3, 6-10, particular roughness parameters projected onto the vertical axis would be more suitable.

11.  The text of this level should not contain sentences beginning with abbreviations or figures. There are several such incorrect sentences in this paper.

12.  The sentence in line 239 needs rephrasing.

13.  From the viewpoint of wood structure variability, the studied issue needs to use more specimens than one for each angle, to guarantee some confidence.

14.  I do not feel competent to express my opinion concerning the chemical changes

 

I highly appreciate the efforts and hard work of the authors. I apologize if I have not understood your methodical approaches and if my critical comments are not fully proficient. I seek my best to provide hints for approving the quality of the paper. I believe that you will not comprehend my suggestions as offensive.

 

Comments for author File: Comments.pdf

Author Response

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Reviewer 2 Report

2.1. Wood samples: to facilitate the reproduction of the results in other studies and to allow a better comparison with other work the authors should provide more details about the wood species used.

The should give information on: density, growth ring width and wood moisture content.

Author Response

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Reviewer 3 Report

Abstract

Abstract need a revision to improve the comprehension of the work. I'll suggest to add the aim of the study. The authors described only methodology and results.

Keywords

Words from the title should not be used as keywords.

 

Introduction is correctly improved but the aim of the paper is not so clear. Please improve better this aspect

2. Materials and Methods

(Acer pseudoplatanus) italic please

 

the authors are invite to explain the reason that determined the size of these wood samples

CNC router was used……Please add picture of this operation if possible or the image of this tool

 

…….feed speeds of 2 m/min, 2.5 m/min, 3 m/min, 3.5 m/min and 4 m/min.…………. please explain because were used these different speeds

 

Results are excessive describe but a synthetic approach could improve this paragraph.

Discussion is not describe

 

Conclusion

Chapter Conclusion is not correct for this type of journal. The conclusions should be written comparing objects of the study and the results obtained. The conclusions repeat the results, not well focused on your findings and know is possible to develop this research. The conclusion is quite short basically including the results. More future developments and conclusions should be considered.

Author Response

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