Review Reports

Round 1

Reviewer 1 Report

The paper deals with a polymer composite reinforced with Kevlar fibers designed to protect humans from shark bites. After production, the composite samples were exposed to seawater, UV radiation, and additionally cured at atmospheric pressure. All samples were tested by a penetration test using a conical steel tool instead of a shark tooth to determine the depth of penetration. This study is an interesting and significant contribution to the development of appropriate material protection against shark attacks. However, the selected materials, i.e., fibrous mats and polymer matrix, together with the production method were not specified at all. Without this sufficiently detailed information, the paper cannot be published.

 

All Roman numerals used as references in the text must be replaced by Arabic numerals.

 

Page 2-3, Sec. 2.1.: The materials used and the method of production of the samples were not specified at all.

 

Page 3, 1st par: “… conical steel penetrants …” This tool should mimic a shark tooth. However, its shape is different and sharp edges are missing, which will affect the nature of the material failure and the penetration depth.

 

Page 3, 2nd par: “… samples were connected to a prismatic clay block with the dimensions 150 x 67 x ~40 mm. This was achieved by wrapping the single extended Kevlar layer around the block and then inserting the assembly into a slightly larger compression box …” How do the size and mechanical properties of the block affect the results of the penetration test?

 

Page 3-4: “… a penetrant displacement of 40 mm was reached …” and “The protective material is not designed to prevent deformation but instead to minimise penetration of the shark teeth beyond the material.” And what about 40 mm deformation of muscle? Is composite stiffness unimportant? No, it must be optimized with respect to the composite application.

 

Page 4, 1st par: Elastic recovery of the flexible material may result in an underestimation of the penetrant diameter ?. What was the correlation of the measured penetrant diameter ? and the penetration depth ? with Equation 1? Can you put it in graph?

Author Response

We want to thank the reviewer for his time and valuable inputs. Please find our detailled response in the attached PDF document.

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper deals with " Fibre-Reinforced Composite for Protection against Shark Bites ". However, the representative preparation of Fibre-Reinforced Composite, including the prepared materials and their characterization, should be described in details. And authors should provide schematic illustration of Fibre-Reinforced Composite concisely and implicitly. This work does not cover the Novelty and Scientific soundness for the publication in such a good like materials. Authors should compare with other similar systems (commercial or reported previously) and provide the academic novelty or technical advantages.

Specific Comments :

Regarding to the experimental section, the authors should be provide the schematic illustration or describe in details the five layers of woven Kevlar fibre stacked and infiltrated with an optimized elastic polymer matrix. Moreover, the possibility of using this fiber composites as a sportswear cannot be predicted because the characteristics of the fiber composites for use as sportswear are missing. Therefore the authors should provide the world-class quality and high novelty with solid data support. (moisture management, UV protect, antimicrobial, thermoregulation, wind resistance, water resistance,…, etc.) Additionally, authors must compare their data to other commercial products or reported previous papers. So, finally, the authors need to prove the academic novelty or technical advantages of this paper with the data created in this way. 

Author Response

We want to think the reviewer for his time and valuable inputs into our manuscript. Please find our detailled response in the attached PDF document.

Author Response File: Author Response.pdf

Reviewer 3 Report

This manuscript presents a novel material for protection against shark bites.  The study demonstrated that the material limit penetration into vulnerable human tissue from shark bite.  This work should be of interest to its industrial application. However, some minor revision will be useful for the quality of this paper. Below are my comments -

1. What polymer was used in this study, what are the polymer properties, can you add just polymer penetration results also?
2. Can you add high magnification images of the composite materials after testing (point of contact with the penetrant)?
3. To simulate shark bite, 21 mm distance were kept between two penetrates – please add a comment what role the tension force in composite material parallel to clay block surface plays to the deformation of the composite material.   

Author Response

We want to think the reviewer for his time and valuable inputs into our manuscript. Please find our detailled reply in the attched PDF file.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The author's response to the reviewer's comment that "the materials used and the method of production of the samples were not specified at all" is as follows: “The manufacturing of the material is a trade secret and can thus not be disclosed;”

 

In principle, the published data must be sufficiently detailed for anyone to repeat the results. I understand that the polymer matrix and manufacturing are trade secrets, but in that case the paper cannot be published.

Author Response

We have received the comments for the 2^nd revision of our manuscript “Fibre-Reinforced Composite for Protection against Shark Bites”. Reviewers II and III now recommend the publication of the manuscript.

However, reviewer I states “The author's response to the reviewer's comment that "the materials used and the method of production of the samples were not specified at all" is as follows: “The manufacturing of the material is a trade secret and can thus not be disclosed;” In principle, the published data must be sufficiently detailed for anyone to repeat the results. I understand that the polymer matrix and manufacturing are trade secrets, but in that case the paper cannot be published.”

We respectfully disagree with this assessment for the following reasons:

1. Publishing data on materials that have not been fully characterised is common practise; see e.g. reference [13] of the submitted manuscript. Otherwise, publications on materials with commercialisation potential would become very difficult.
2. The results can be repeated. The company (Aqua Armour) can provide samples to other research teams on request.

We therefore hope that the manuscript can be published in its current form, as we believe that it is an important contribution to this emerging research field.

Reviewer 2 Report

The questions raised by referees have been reasonably answered. The revised version shows improvement in comparison with the previous version. I recommend its acceptance for publication after minor revision (typos and text editing).

Author Response

We thank the reviewer for this positive assessment.

1. The text has been carefully proof read to remove typos.
2. We understand that text editing will be finzlied by the publisher but have also attempted to improve the layout.