The Influence of High-Temperature and -Pressure Treatment on Physical Properties of Albizia falcataria Board

Round 1

Reviewer 1 Report

The paper analyzes the effects of densification processes under high temperature and pressure, applied to Albizia Falcataria boards. As this is a fast-growing species, the objective of the research is to improve its physical and mechanical properties in order to broaden its scope of use, mainly in the construction market.

As the authors point out, these considerations are relevant in the current context, given the increase in wood consumption associated with the search for greener strategies. The topic is also relevant to the scope of the journal.

The procedure adopted involves densification treatment in four phases: vacuum, softening, compressing and cooling. The samples are subjected to different temperature levels, so that at the end of the process, and over a period of two weeks, the effects in terms of density, color, thickness, compression ratio, equilibrium moisture content and anatomical properties are comparatively analyzed.

Title and abstract satisfactorily describe the content of the paper. The procedures used are also adequate and, in general terms, sufficiently described. The final conclusions are globally valid, as they summarize the observations on treatment effects. However, they can be supplemented with quantitative assessments in certain aspects, just as some statements may be questionable. The bibliography is considered relevant and sufficiently representative of the state of the art.

Consequently, our opinion is favorable to the publication of the paper. In any case, we consider that some questions should be corrected or clarified, according to the following observations and suggestions.

Line 47: A blank space is missing, between "use" and "[8,9]".

Line 80: It is suggested that the regulations be incorporated into the bibliographic references, as usual.

Lines 78 to 85: It is unknown how many samples have been prepared and analyzed for each of the treatments described. It is known that wood presents a greater dispersion of results, in all kinds of tests, compared to other types of materials. For this reason, it is usual to adopt sample collections that are statistically significant.

Figure 1: It is strongly recommended to harmonize the size of texts and graphics to facilitate their readability.

Line 102: It is considered that the compression phase can be better documented (time and speed of the process, dimensions of the steel plate, organization of the equipment, perhaps a photograph could also be helpful).

Line 106. A blank space is missing, between “[27].” and “After”.

Line 115: Check the size of the font used in equation (1).

Lines 116 to 118: We understand that this paragraph comes from the template of the paper, and therefore should be deleted. The same can be said in relation to lines 126 to 128.

Line 124: It is suggested to add (SR) after "set-recovery", since the abbreviation is used later (table 1).

Lines 125 to 132 (in addition to deleting lines 126 to 128): It is understood that the set-recovery parameter, as defined in equation 2 and developed in table 1, is established in terms of density (kg / l, both in figure 3 and in table 1). Therefore, the units indicated for Ds (%), Da (mm) and Do (mm) are considered inappropriate.

Line 129: Clearly EMC refers to "equilibrium moisture content". However, and since the acronym has not been defined previously, it is recommended to specify the full name.

Line 133: It is recommended to replace "Dc" by "DC", in accordance with the criteria used with other variables and with the content of Table 1.

Lines 142 to 147: It is recommended to add the expressions with which TS and TC are determined, as it has been done with SR and DC for the density. It would also be desirable to use a different abbreviated designation for set-recovery, depending on whether it is used with densities or thicknesses (SR is used in both tables 1 and 3).

Line 152: In line 145 Tc identifies the change in thickness (it is understood in percentage terms), while in line 152 and in equation (4) it would correspond to the final thickness obtained after compression.

Line 175: It is considered that the words "and parameters" can be deleted.

Lines 183 to 185: The authors first state that the variation in temperature does not have a notable effect on the densification of the wood. And later, that the treatment at 140º results in a density lower than that of 120º. The results do not seem very conclusive, and in any case they should be reviewed based on the size of the collection tested, which, as indicated, is unknown.

Lines 208 to 211: The conclusions are doubtful, at least in view of the photograph provided. In any case, the quantification of the camber effects can be better explained. The authors point out that it is necessary to examine further the configuration of the steel plate used in the sandwich category. This question also needs to be explained better: it is unknown whether the loss of flatness occurs during the pressing process, as the reference to the plate suggests, or during the subsequent cooling phase, as it would seem more logical.

Line 221: There is a mistake in the numbering of both figures, which must be 4 and 5.

Section 3.5: The conclusions can be improved, including quantitative assessments.

Figure 6: The size of the legend graphics should be enlarged, for a better interpretation of the shading used.

Line 287: The authors state that the increase in density obtained "gives the board excellent strength". However, this has not been proven, as no specific tests have been undertaken to this effect. Rather, it should be noted that an increase in mechanical properties is expected in view of microscopic observation and the available literature.

Reference 6: It is understood that the author is Masafumi Inoue, and therefore the reference should be Inoue, M. Also, "Fist" should be replaced by "First". It is also suggested that the same notation be used as in other proceedings on the list.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Authors

I had the opportunity to review the paper proposed for Forests under the name "The Influence of High Temperature and Pressure Treatment on Physical Properties of Albizia Falcataria Board". In attachment I present some suggestions/questions which autors should be considered in or fill in.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf