The Effect of Chopped Carbon Fibers on the Mechanical Properties and Fracture Toughness of 3D-Printed PLA Parts: An Experimental and Simulation Study
, Ali Basem 2, Mohammed Salman Kadhim 3, Zainab T. Al-Sharify 4,5, Alaa Abdulhady Jaber 6,*, Emad Kadum Njim 7, Luttfi A. Al-Haddad 8, Mohsin Noori Hamzah 6 and Ehsan S. Al-Ameen 1Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis study investigates the tensile and fracture behavior of 3D printed PLA composites reinforced with chopped carbon fibers through experimental characterization and finite element analysis. The whole manuscript is logically clear and well arranged, and it is recommended for publication after revision.
1. please explain why the carbon fiber is used for the PLA properties improvement.
2. The advantages or strengths of 3D printing the sample, with comparison with other methods, in mechanical properties enhancement.
3. Curves in Fig. 5 can be drawn in one single figure for comparison, so does the Figure 6.
4. Why only the A1 sample is used for the FEA simulations.
Comments on the Quality of English LanguageMinor editing of English language required
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors1. Emphasise the novelty of the work in the final paragraph of the introduction.
2. In the concluding paragraph of the introduction, summarize what was done, how it was accomplished, and the findings.
3. Explain the merit and motivation for studying the specific composites.
4. Have you done any de-sizing process on the short fibre before mixing it with PLA?
5. Page 6, “… fibers in the PLA/CF filaments was 17.42 wt%, a common value in chopped fiber…”. What is your reference for this? There is no common value for chopped fibre. Depending on the type of fibres and matrix, the optimum fibre content to reach maximum strength could be measured.
6. Refer to the below work, they have investigated the same approach to reinforce polymers with short and continuous fibres, make filament and 3D print composite filaments. It is critical to mention such works in the introduction section and highlight the novelty of your work.
Circular economy innovation: A deep investigation on 3D printing of industrial waste polypropylene and carbon fibre composites
Micromechanics study of short carbon fiber-reinforced thermoplastics fabricated via 3D printing using design of experiments
Degradation characteristics of 3D printed continuous fibre-reinforced PA6/chopped fibre composites in simulated saltwater
7. Page 6, “The filaments were extruded to a diameter of 1.75 mm”. How did you control the diameter of the fabricated filament? Add a figure to show the filament-making process and the final filament.
8. Move the section “3.1.1. Reinforcement Mechanism” to the introduction.
9. Page 6, line 271: What are “(model and manufacturer details).”?
10. Page 6, line 276, “a nozzle with a diameter of 0.4 mm”. It is not possible or very difficult to print a filament reinforced with a 17 wt.% fibre content, by a printer with a 0.4mm nozzle diameter because of fibre clogging.
11. Add figures of the manufacturing process and printed samples.
12. Page 8, line 324, “Uniaxial tensile tests were performed on an Instron 5980 system at a crosshead speed of 1 mm/min according to the ASTM D638 procedures”. The ASTM D638 procedure is utilized for tensile testing of plastics not reinforced samples. Why did you use this standard?
13. What is shown in Figure 8?
14. There is no real discussion in this manuscript. You need to discuss the results and justify the observations.
15. Remove the FE modelling from the manuscript.
16. Use bullet points to highlight the main achievements in the conclusion section.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript can be accepted now.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe paper is accepted in its current form.
