Hot-Air Contactless Single-Point Incremental Forming
Round 1
Reviewer 1 Report
The manuscript intitle "Hot Air Contactless Single Point Incremental Forming" present an experimental study of a novel sheet forming technique that is uses hot compressed air as a deformation tool, eliminating the requirement of a rigid forming tool. the The increasingly high demands placed on the production of plastic elements cause the need to develop new manufacturing methods able to offer superior machining characteristics. The manuscript presents a well-written, comprehensive overview of the ingle Point Incremental Forming process. The manuscript is easy to follow and provides a valuable information on the posibility and advantage of using compressed hot air as forming tool for machining polycarbonate sheets. The discussion includes some interesting idea and a proposition of a new sheet forming manufacturing process. Some positive effects were reported in terms of surface quality and reduction of defects such as tearing and twisting. The paper includes some original and interesting elements that sustain its publication.
The paper presents some interesting aspect regarding the possibility of carry out single point forming processes with contactless tools. Although the paper is well structured there are some changes that need to be made in order to to sustain its publication.
1. Please provide more information about the tool trajectory used (see: Kurra Suresh , Arman Khan, Srinivasa Prakash Regalla, Tool path definition for numerical simulation of
single point incremental forming, International Conference On DESIGN AND MANUFACTURING, IConDM 2013, Procedia Engineering 64 ( 2013 ) 536 – 545 )
2. You have to introduce the full name; producer and the producer s headquarter location for all the equipment and devices used in the experiment. What type of CMM and measuring strategy you used in order to determine the X, Y, and Z displacements. What is the accuracy of the CMM?
3. Line 334 The group of words ”Sheet thinning is a typical” is repeated.
4. You must provide legends for the thermal images from figure 6
5. Data from table 1 needs formatting, the text size is too big.
6. The text in the image from figure 2 do not match the paper text body.
7. You must leave a space between the value and the measurement unit. Please do these corrections for all the values in the text.(example 5 mm)
8. Remove the point before Figure 8. tittle. The text from the graphs from figure 8 should have the same size as the text from the paper body.
9. You must provide information and definitions for each roughness parameter from Table 3.
10. Not all references do have the formatting style indicated in the author guidelines(see template file
Author Response
Hot Air Contactless Single Point Incremental Forming
The authors are extremely grateful for the very helpful and constructive suggestions made by the editor. The authors have carefully considered all the points raised, and the following changes have been made in response to the comments.
Reviewers #1:
The manuscript intitle "Hot Air Contactless Single Point Incremental Forming" present an experimental study of a novel sheet forming technique that is uses hot compressed air as a deformation tool, eliminating the requirement of a rigid forming tool. the increasingly high demands placed on the production of plastic elements cause the need to develop new manufacturing methods able to offer superior machining characteristics. The manuscript presents a well-written, comprehensive overview of the single Point Incremental Forming process. The manuscript is easy to follow and provides a valuable information on the possibility and advantage of using compressed hot air as forming tool for machining polycarbonate sheets. The discussion includes some interesting idea and a proposition of a new sheet forming manufacturing process. Some positive effects were reported in terms of surface quality and reduction of defects such as tearing and twisting. The paper includes some original and interesting elements that sustain its publication.
The paper presents some interesting aspect regarding the possibility of carry out single point forming processes with contactless tools. Although the paper is well structured there are some changes that need to be made in order to sustain its publication.
Response:
The authors thank the reviewers, and they revised the paper accordingly.
Comment 1:
Please provide more information about the tool trajectory used (see: Kurra Suresh , Arman Khan, Srinivasa Prakash Regalla, Tool path definition for numerical simulation of single point incremental forming, International Conference On DESIGN AND MANUFACTURING, IConDM 2013, Procedia Engineering 64 ( 2013 ) 536 – 545 ).
Response 1:
The path, shaped like a truncated pyramid, was created using consecutive parallel loops. It commenced with a 152 mm × 120 mm rectangle in the initial loop. Each loop rectangle decreases by 5 mm from each side and concludes with a 62 mm × 30 mm rectangle in the last loop, with each loop step-down of 0.75 mm. As illustrated in Figure 3B, the initial trajectory follows a straight path in both clockwise directions, denoted as '1' and '2,' until it returns to its starting point. Subsequently, it shifts along the X and Z axes, as indicated by direction '3,' before proceeding in '4' direction along the Y axis to initiate the subsequent descent. This movement pattern continues until the last path.
Figure 3 Truncated pyramid path trajectory
Comment 2:
You have to introduce the full name; producer and the producer s headquarter location for all the equipment and devices used in the experiment. What type of CMM and measuring strategy you used in order to determine the X, Y, and Z displacements. What is the accuracy of the CMM?
Response 2:
The authors gave more details on equipment and for CMM as suggested.
A Mitutoyo Coordinate Measuring Machine, the Euro-CA776 (CMM), with an accuracy of (1.7 + 0.3L/100) µm was used. The measuring strategy employed involved sensing discrete points using a trigger probe that was positioned along the cross-section of the workpiece, from one edge to the other. The coordinates for each point were determined from both the top and bottom sides. The top side measurements provided the profile data, while measurements of the bottom side were used to calculate the thickness of the sheet on the surface.
A Mitutoyo Formtracer Avant S-3000 Model Surface Roughness Tester with an accuracy of (0,05+0,001L) µm was used.
Comment 3:
Line 334 The group of words ”Sheet thinning is a typical” is repeated.
Response 3:
The authors corrected this error as suggested. (Line350)
Comment 4:
You must provide legends for the thermal images from figure 6.
Response 4:
The authors added the legends for the thermal images as suggested.
Note: Figure 6 becomes to be Figure 7 after added the Truncated pyramid path trajectory Figure.
Comment 5:
Data from table 1 needs formatting, the text size is too big.
Response 5:
The text size reduced as requested.
Comment 6:
The text in the image from figure 2 do not match the paper text body.
Response 6:
The authors corrected this error as suggested.
Comment 7:
You must leave a space between the value and the measurement unit. Please do these corrections for all the values in the text. (example 5 mm).
Response 7:
The authors corrected this error as requested.
Comment 8:
Remove the point before Figure 8. tittle. The text from the graphs from figure 8 should have the same size as the text from the paper body.
Response 8:
The authors corrected this error as requested.
Comment 9:
You must provide information and definitions for each roughness parameter from Table 3.
Response 9:
The authors provided the information and definitions for each roughness parameter as requested.
In this study, four different roughness parameters were measured: the Average Roughness (Ra) value, which is an internationally recognized parameter for measuring surface roughness and the mean departure of a profile; the Root Mean Square (Rq) value, determined as the square root of the mean squared roughness values over the evaluation length; Rz, calculated as the average of the five highest peaks and five deepest valleys within the evaluation length, offering insights into the height of surface irregularities by accounting for both peaks and valleys; and finally, Rt, which quantifies the total height discrepancy between the highest peak and lowest valley within the evaluation length, providing an assessment of the overall height variation across the surface.
Comment 10:
Not all references do have the formatting style indicated in the author guidelines (see template file).
Response 10:
The authors corrected the references as requested.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript proposes the Hot Air Contactless Single Point Incremental Forming (HASPIF) technique, that is an novel alternative to the Single Point Incremental Forming (SPIF) process: hot compressed air is used to deform the material instead of a rigid tool, thus eliminating friction issues. The article is easy to read, references both in the introduction and in the results are appropriate, it is original and has notable knowledge also for industrial applications. However, some issues are suggested to be dealt before publication:
Abstract:
- Line 13: remove "is"
Methodology:
- Being a novel methodology, process variability is unknown. How many replications of the experimental test have you made (if any)? What is the standard deviation between the replications? If no replications of the test were done, please specify.
Results:
- Line 319: please correct the equation 2, adding the multiplication sign.
- Line 321: the thickness of the workpiece can be deretmined through equation (2), isn't it?
- Line 334: remove the repetition of "Sheet thinning is a typical"
- Figure 8: correct the term "distribution" in the graph
Author Response
Hot Air Contactless Single Point Incremental Forming
The authors are extremely grateful for the very helpful and constructive suggestions made by the editor. The authors have carefully considered all the points raised, and the following changes have been made in response to the comments.
Reviewers #2:
The manuscript proposes the Hot Air Contactless Single Point Incremental Forming (HASPIF) technique, that is an novel alternative to the Single Point Incremental Forming (SPIF) process: hot compressed air is used to deform the material instead of a rigid tool, thus eliminating friction issues. The article is easy to read, references both in the introduction and in the results are appropriate, it is original and has notable knowledge also for industrial applications. However, some issues are suggested to be dealt before publication:
Comment 1:
Abstract:
- Line 13: remove "is"
Response1:
The authors corrected this error as requested.
Comment 2:
Methodology:
Being a novel methodology, process variability is unknown. How many replications of the experimental test have you made (if any)? What is the standard deviation between the replications? If no replications of the test were done, please specify.
Response 2:
This study involved four repetitions of experiments for selected parameters, incorporating sensitivity analysis. The standard deviation for testing was found to be 0.6452 mm.
Comment 3:
Results:
1- Line 319: please correct the equation 2, adding the multiplication sign.
2- Line 321: the thickness of the workpiece can be deretmined through equation (2), isn't it?
3- Line 334: remove the repetition of "Sheet thinning is a typical"
4- Figure 8: correct the term "distribution" in the graph
Response 3:
1- The multiplication sign is added to the equation 2.
2- Yes, the thickness of the workpiece can be determined through equation (2), typo mistake has been corrected.
3- The authors remove the repetition of "Sheet thinning is a typical as requested.
4- The authors corrected the term "distribution" in the graph.
Author Response File: Author Response.docx
Reviewer 3 Report
The introduction is too long. The authors should present the results of literature research, primarily related to the formation of polymers by the incremental forming method.
Why the authors chose process parameters arbitrarily table 2. Are these all relevant parameters. How do these parameters relate to the results of other researchers? Please explain and supplement in the article
During plastic shaping, the principle of constant material volume applies. If a solid is formed from a sheet of metal, it is done by reducing the thickness of the sheet. The reduction in sheet thickness is greater the greater the local deformation. Have the authors detected a deviation from this rule? Please explain .
The article is a validation test of the HASPIF method for arbitrarily selected parameter values. Several parameter values should be tested. And if these parameters are optimal, please document it better
Author Response
Hot Air Contactless Single Point Incremental Forming
The authors are extremely grateful for the very helpful and constructive suggestions made by the editor. The authors have carefully considered all the points raised, and the following changes have been made in response to the comments.
Reviewers #3:
Comment 1:
The introduction is too long. The authors should present the results of literature research, primarily related to the formation of polymers by the incremental forming method.
Response 1:
The authors shorted the introduction as requested.
Comment 2:
Why the authors chose process parameters arbitrarily table 2. Are these all relevant parameters. How do these parameters relate to the results of other researchers? Please explain and supplement in the article.
Response 2:
The parameter choices were informed by the most efficient parameters used in the conventional SPIF process, specifically the feed rate and step-down, in combination with those relevant to the new tool. Additionally, new parameters, including air pressure, air temperature, and initial gap, were introduced through experimental determination to optimize the performance of the newly implemented hot compressed air tool.
Comment 3:
During plastic shaping, the principle of constant material volume applies. If a solid is formed from a sheet of metal, it is done by reducing the thickness of the sheet. The reduction in sheet thickness is greater the greater the local deformation. Have the authors detected a deviation from this rule? Please explain.
Response 3:
During the deformation, with the local deformation and the temperature remaining consistently low around the glass transition temperature, the sheet exhibited properties similar to those of a rubbery solid. A uniform reduction in thickness was observed from the initial point to the bottom corner, consistent with the principle of constant material volume. Subsequently, a slight material build-up was noticed at the bottom corner of the sheet. This occurrence was attributed to the increasing heat as the tool path decreased, leading to a reduction in cooling time.
Comment 4:
The article is a validation test of the HASPIF method for arbitrarily selected parameter values. Several parameter values should be tested. And if these parameters are optimal, please document it better.
Response 4:
This paper represents a preliminary study, aimed at demonstrating the concept of the novel tool. A separate journal paper, which focuses on optimizing the contactless Single Point Incremental Forming process.
Author Response File: Author Response.docx
