Particleboards from Recycled Thermally Modified Wood

Round 1

Reviewer 1 Report

The manuscript is focused on an important research topic, namely the recycling of particleboards from thermally modified wood. Because of which there will interest in readers.

The Abstract is very well-structured substantiating the relevance of the study and indicating the main results from the conducted research.

In general, the Introduction is well constructed and justifies the relevance of the study

In my opinion, it would be good to present in more detail the researches for the production of PBs with the content of TMW. That is, in more detail to present the studies given in the sentence: „The properties of PBs manufactured with content of TMW are by more  authors [19, 21, 22, 23, 24, 25, 26, 27, 28] as follows: better dimensional stability; reduced water absorption; improved MOE; similar MOR (although some authors showed reduction of MOR); reduced internal bond“ (lines 68÷71). It would also be good to broaden the context by providing data for recycling and other types of wood materials. For example, suitable publications are DOI: 10.3390 / polym13040639; DOI: 10.1080 / 17480272.2020.1826578; as of course and others.

In the material and methods - 2.1.2. Resin and Additives: Please give more detailed information about the UF resin – malar ratio, viscosity, gelling time. Were the resins for face and core layerс with the same molar ratio? In the adhesive system do you use any type of formaldehyde scavenger (urea or another one)?

The results are very well presented as they are put in the context of another similar research.

The Conclusions provided are well-formulated, but my recommendation is not to structure them with bullets, but to give them as a final analysis of the study. 

Author Response

Reviewer 1:   Thank you for the review.

The manuscript is focused on an important research topic, namely the recycling of particleboards from thermally modified wood. Because of which there will interest in readers.

The Abstract is very well-structured substantiating the relevance of the study and indicating the main results from the conducted research.

In general, the Introduction is well constructed and justifies the relevance of the study

Point 1

In my opinion, it would be good to present in more detail the researches for the production of PBs with the content of TMW. That is, in more detail to present the studies given in the sentence: „The properties of PBs manufactured with content of TMW are by more  authors [19, 21, 22, 23, 24, 25, 26, 27, 28] as follows: better dimensional stability; reduced water absorption; improved MOE; similar MOR (although some authors showed reduction of MOR); reduced internal bond“ (lines 68÷71). It would also be good to broaden the context by providing data for recycling and other types of wood materials. For example, suitable publications are DOI: 10.3390 / polym13040639; DOI: 10.1080 / 17480272.2020.1826578; as of course and others.

Response to point 1:

• “Pelaez-Samaniego et al. (2013) [15] summarized the use of TMW for production of wood composites. The properties of PBs manufactured with content of TMW are by more authors [19, 21, 22, 23, 24, 25, 26, 27, 28] as follows: better dimensional stability at exposure to wett environment; reduced water absorption; partly improved moduly of elasticity; similar or reduced strengths; and usually reduced internal bond“.
• Some other data related to properties of PBs made with TMW particles are mentiond in the Chapter „Results and Discussion“.
• Now we added also a part related to a hypothetical effect of FTIR and compression strength parallel with grains of the used woods (spruce vs. TMWs) on selected properties of PBs.

Point 2

In the material and methods - 2.1.2. Resin and Additives: Please give more detailed information about the UF resin – malar ratio, viscosity, gelling time. Were the resins for face and core layerс with the same molar ratio? In the adhesive system do you use any type of formaldehyde scavenger (urea or another one)?

Response to point 2:

• Detail information about the used UF resins for PBs were published in our previous work Iždinský et al. 2020 [38] – see Table 1.
• Molar ratio was 1.2 (M/F).

Table 1. Properties of UF resins .

Quality parameters	Unit	Method	KRONORES CB 4005 D	KRONORES CB 1637 D
Solid content	%	EN 827 [41]	65.87	67.35
Ford cup viscosity 4mm/20 °C	s	EN ISO 2431 [42]	76	86
pH value		EN 1245 [43]	9.08	8.62
Gel time at 100 °C	s	Kronospan chloride test	81	36

The results are very well presented as they are put in the context of another similar research.

Point 3

The Conclusions provided are well-formulated, but my recommendation is not to structure them with bullets, but to give them as a final analysis of the study. 

Response to point 3: The formulations in „Conclusion“ with bullets we used also in Forests (2020).  

Author Response File: Author Response.pdf

Reviewer 2 Report

“Particleboard from recycled thermally modified wood” describes the biological effectiveness and the mechanical and moisture properties of particleboards made from waste thermally modified wood. It is an interesting attempt towards sustainable use of timber. The research was well-planned and described. I have only a few comments and suggestions on the text (see the pdf file attached).

Comments for author File: Comments.pdf

Author Response

Reviewer 2:  Thank you for the review.

“Particleboard from recycled thermally modified wood” describes the biological effectiveness and the mechanical and moisture properties of particleboards made from waste thermally modified wood. It is an interesting attempt towards sustainable use of timber. The research was well-planned and described. I have only a few comments and suggestions on the text (see the pdf file attached).

Point 1

A one-sentence conclusion is needed here.

 

Response to point 1:

In summary, the recycled TMW particles can improve the decay and water resistance of PBs exposed to higher humidity environment, however, worsening of their mechanical properties could appear, as well.

 

Point 2

Please use both full names and abbreviations here to make the table easier to read. The same refers to other tables and figures.

Response to point 2:

Yes, it was made.

 

Point 3

Please give here some potential examples of application of the PBs prepared in the study.

Response to point 3:

Yes, it was done in the end of „Results and Discussion“.

From the practical point of views, the PBs made with a portion of recycled TMW could be applied for special interior exposures, e.g., kitchens and bathrooms, where sometimes a relatively high humidity of air acts with the aim to protect products made from these boards from moisture and fungal attacks.   

Author Response File: Author Response.pdf