Fibers Obtained from Invasive Alien Plant Species as a Base Material for Paper Production
Round 1
Reviewer 1 Report
This study is important that invasive alien plants are changed into useful materials for environmental and economic benefits. The scope of this research fits to the journal guidelines. I would recommend this manuscript undergoes a minor revision. Few of the points to address:
- In line 1-2 of page 3, “we did not find any other studies ~ for papermaking”,The title didn't say "for making paper," but there are pictures about their transparency after making papers. Therefore, modify this expression into a different sentence.
- → Already published the paper on Tall goldenrod of invasive alien plant. For example: Kim HG, Lee US, Kwac LK, Lee SO, Kim YS, Shin HK. Electron beam irradiation isolates cellulose nanofiber from Korea “Tall Goldenrod” invasive alien plant pulp. Nanomaterials 2019, 9, 1358.
- Please attach a picture of the respective plants in “Morphological macroscopics differentials” of table 1 and table 2, and compare them. In addition, the raw materials used to make paper rather than leaves and flowers is the trunk of a plant. I think that explanation about the trunk should be emphasized.
- What are the content of cellulose, hemicellulose, lignin, and pectin and so on of respective plants?
- In the preparation of cellulose papers from invasive alien plant, here is no section how lignin and hemicellulose is removed to isolate cellulose fibers. Cooking and bleaching process for isolation of cellulose fibers should be provided.
- In Table 4 and 5 of page 8, please clarify the sample name, not 1,2,3, and4.
- In line 22-48 of 23 page, as mentioned in title of “Cellulose fibers extracted from invasive alien plant species as a base material for paper production”, cellulose fiber extraction means the removal of lignin and hemi-cellulose. This paragraph doesn’t fit your title. If a large amount of lignin and hemi-cellulose is present or not removed, the title correct from “cellulose fibers extracted from invasive alien plant~” into “Fibers obtained from invasive~”. In other words, sample papers did not obtain by extraction of cellulose fibers removed lignin and hemi-cellulose but by physically fibrillation of the trunk of plant
Author Response
Description of revisions made
The manuscript ID Forest–1176007 has been revised according to the recommendations of both reviewers.
Reviewer 1
1. In line 1-2 of page 3, “we did not find any other studies ~ for papermaking”. The title didn't say "for making paper," but there are pictures about their transparency after making papers. Therefore, modify this expression into a different sentence.
Expression was modified: In the databases and literature analysed, we did not find any other studies on the invasive alien plant species used as a base material for paper production, so we decided to further investigate …
2. Already published the paper on Tall goldenrod of invasive alien plant. For example: Kim HG, Lee US, Kwac LK, Lee SO, Kim YS, Shin HK. Electron beam irradiation isolates cellulose nanofiber from Korea “Tall Goldenrod” invasive alien plant pulp. Nanomaterials 2019, 9, 1358.
This reference was added to the text on page 2: Kim et al. [6] isolated cellulose nanofibers from pulps of a tall goldenrod (Solidago altissima), an invasive plant in Korea, using electron beam irradiation. Nanofibres were characterized, and paper samples prepared. Papers produced from more finely separated fibers, generated by using higher doses of electron beam irradiation, had enhanced UV–vis transmittance, lower thermal stability, higher char yield, and increased tensile strengths.
3. Please attach a picture of the respective plants in “Morphological macroscopics differentials” of table 1 and table 2, and compare them. In addition, the raw materials used to make paper rather than leaves and flowers is the trunk of a plant. I think that explanation about the trunk should be emphasized.
Pictures depicting the main morphological differences have been added. The photographs were taken during the project work and are the work of the authors.
4. What is the content of cellulose, hemicellulose, lignin, and pectin and so on of respective plants?
Added Table 4, where the chemical analysis of IAPS is reported.
5. In the preparation of cellulose papers from invasive alien plant, here is no section how lignin and hemicellulose is removed to isolate cellulose fibers. Cooking and bleaching process for isolation of cellulose fibers should be provided.
Added Table 4.
6. In Table 4 and 5 of page 8, please clarify the sample name, not 1,2,3, and4.
Sample names have been clarified.
7. In line 22-48 of 23 page, as mentioned in title of “Cellulose fibers extracted from invasive alien plant species as a base material for paper production”, cellulose fiber extraction means the removal of lignin and hemi-cellulose. This paragraph doesn’t fit your title. If a large amount of lignin and hemi-cellulose is present or not removed, the title correct from “cellulose fibers extracted from invasive alien plant~” into “Fibers obtained from invasive~”. In other words, sample papers did not obtain by extraction of cellulose fibers removed lignin and hemi-cellulose but by physically fibrillation of the trunk of plant
Chemical analysis of IAPS and preparation of cellulose fibers is presented in Table 4.
With kind regards, Ljubljana, 13. 4. 2021
assist. prof. Klemen Možina, PhD
Author Response File: 
Author Response.pdf
Reviewer 2 Report
In this manuscript the authors report a thorough study making paper from three different invasive species (Knotweed, Goldenrod, and Black Locust). The paper made from the invasive species is compared to commercial office paper. For all types of paper, the mechanical, structural, physical are studied, in addition to the effects of UV radiation on properties. The results are encouraging in that paper from invasive species can be made and perform similar to commercial office paper. The main drawback is that the paper from invasive species is not as white as commercial office paper. Overall, the paper is well-written, and the results are thoroughly reported. The manuscript will be of interest to Forests readers. However, before publication the following items should be addressed:
- Abstract: Define the acronym IAPS before it is used the first time.
- It is difficult for a first-time reader to remember what samples labeled “S1”, “S2”, “S3”, and “S4” are. It is recommended to use something more intuitive for the reader, such as KW, BL, GR, and COP.
- What was the moisture level during DMA of the as-prepared and UV-treated specimens?
- It would be useful to provide additional details about the pulping process and how the IAPS material was prepared to make the paper. For example, was the whole stalks with leaves and flowers and roots used? How were the IAPS materials harvested?
- What type of fibers were in the commercial office paper?
- Table 4: It appears two images in the Sample 1 row are switched. In the associated text, it is mentioned that the images in Table 4 can be used to determine paper thickness. How can you tell from the images in Table 4 what the paper thickness is?
- Section 3.2.2: The text here does not line up with the values in the table. The table has thicknesses of 0.102 to 0.208 mm, whereas the text says the acceptable range is 0.002 to 0.004 mm.
- Section 3.2.5: Again, the values in the text do not correspond to the values in the table.
- Table 7: Define all the variables in the table heading. Is F15 the tensile strength?
- Section 3.3.1: It looks like the tensile values of the paper are about 2x higher in the MD and CD, not 1x higher.
- Section 3.3.3: This section mentions a chapter in a thesis.
- Section 3.3.3: This section mentions the relative proportions of hemicelluloses and lignin in the different papers. How were the relative proportions measured and where can the reader find this data?
- Figures 4-13: These figures are very difficult to read and seem to include a lot of analysis that is not reported in the text. It is recommended to remake all these figures to be more reader friendly.
- Throughout the manuscript, the authors are recommended to reconsider the precision of the reported numerical values. For example, in Table 7 the uncertainty of F15 is reported to three significant digits. Most likely, only one significant digit is warranted for the uncertainty. So, for example, report 82 +/- 6 instead of 81.99 +/- 5.54. Reporting only the meaningful significant digits makes it easier for the reader to comprehend.
Author Response
Description of revisions made
The manuscript ID Forest–1176007 has been revised according to the recommendations of both reviewers.
Reviewer 2
In this manuscript the authors report a thorough study making paper from three different invasive species (Knotweed, Goldenrod, and Black Locust). The paper made from the invasive species is compared to commercial office paper. For all types of paper, the mechanical, structural, physical are studied, in addition to the effects of UV radiation on properties. The results are encouraging in that paper from invasive species can be made and perform similar to commercial office paper. The main drawback is that the paper from invasive species is not as white as commercial office paper. Overall, the paper is well-written, and the results are thoroughly reported. The manuscript will be of interest to Forests readers. However, before publication the following items should be addressed:
1. Abstract: Define the acronym IAPS before it is used the first time.
Acronym was defined.
2. It is difficult for a first-time reader to remember what samples labeled “S1”, “S2”, “S3”, and “S4” are. It is recommended to use something more intuitive for the reader, such as KW, BL, GR, and COP.
The specimen names have been replaced with more intuitive abbreviations, as suggested.
3. What was the moisture level during DMA of the as-prepared and UV-treated specimens?
Liquide nitrogen atmosphere (DMA) and 35 % RH and 35 °C for Xenon test.
(added in chapter 2.2.5. UV impact).
4. It would be useful to provide additional details about the pulping process and how the IAPS material was prepared to make the paper. For example, was the whole stalks with leaves and flowers and roots used? How were the IAPS materials harvested?
Only the stalks were used (Table 4). Added: Table 4 shows the chemical analysis of the paper produced from IAPS, for which 300 kg of air-dried biomass was included in one batch, with only the stems, excluding leaves, flowers and/or roots, cut into 3–5 cm chips [7].
5. What type of fibers were in the commercial office paper?
Spruce, pine, eucalyptus and beech (text added in section 2.1)
6. Table 4: It appears two images in the Sample 1 row are switched. In the associated text, it is mentioned that the images in Table 4 can be used to determine paper thickness. How can you tell from the images in Table 4 what the paper thickness is?
The images were replaced. The expression thickness was replaced by robust: Corrected text: …. the papers made from IAPS are more textured and robust compared to office papers.
7. Section 3.2.2: The text here does not line up with the values in the table. The table has thicknesses of 0.102 to 0.208 mm, whereas the text says the acceptable range is 0.002 to 0.004 mm.
The numbers are correct, since the standard deviation was addressed and not directly the thickness of the paper. We wanted to emphasize the evenness in thickness of the produced papers from IAPS cellulose fibers in comparison to the COP.
8. Section 3.2.5: Again, the values in the text do not correspond to the values in the table.
The values were corrected.
9. Table 7: Define all the variables in the table heading. Is F15 the tensile strength?
The values were corrected.
10. Section 3.3.1: It looks like the tensile values of the paper are about 2x higher in the MD and CD, not 1x higher.
The value was corrected.
11. Section 3.3.3: This section mentions a chapter in a thesis.
It was corrected to ”in chapter of the paper”.
12. Section 3.3.3: This section mentions the relative proportions of hemicelluloses and lignin in the different papers. How were the relative proportions measured and where can the reader find this data?
Table 4 was added.
13. Figures 4-13: These figures are very difficult to read and seem to include a lot of analysis that is not reported in the text. It is recommended to remake all these figures to be more reader friendly.
Figures have been explained in detail in the text: The viscoelastic curves, i.e., storage modulus E', loss modulus E'', damping factor tanδ and dimension L of the samples are shown in Figure 3–8, while the storage modulus values at 20 °C and the temperature of the relaxation transitions Tr are shown in Table 10. The storage modulus E' (marked as green curves in Figure 6–9) is proportional to the energy stored by the material in one deformation cycle and represents the elastic response of the material. The loss modulus E'' (marked as blue curves in Figure 6–9) is proportional to the energy (heat) dissipated by the material in one cycle and represents the viscous response of the material. The damping factor tanδ (marked as brown curves in Figure 6–9), represents the ratio of the viscous to elastic response and is a measure of damping in the material. The length L (marked as pink curves in Figure 6–9), represents the change in dimensions of the sample (shrinking or expanding).
14. Throughout the manuscript, the authors are recommended to reconsider the precision of the reported numerical values. For example, in Table 7 the uncertainty of F15 is reported to three significant digits. Most likely, only one significant digit is warranted for the uncertainty. So, for example, report 82 +/- 6 instead of 81.99 +/- 5.54. Reporting only the meaningful significant digits makes it easier for the reader to comprehend.
Thank you for your suggestion, the numerical values were corrected.
With kind regards, Ljubljana, 13. 4. 2021
assist. prof. Klemen Možina, PhD
Author Response File: Author Response.pdf
