Process Data-Based Knowledge Discovery in Additive Manufacturing of Ceramic Materials by Multi-Material Jetting (CerAM MMJ)

Round 1

Reviewer 1 Report

The authors present a Data-based knowledge discovery procedure employed in Additive Manufacturing of ceramic materials. The manuscript is well organized and well written. It could become accepted upon some minor issues listed below:

1. References should be before the end of the sentences.
2. Any more works on the use of DM and ML for Additive manufacturing or material synthesis? Would be ideal to present a literature review focused on these; even if these are not for ceramic or multi-material additive manufacturing.
3. A section of materials&methods is missing, this in order to answer questions like:
   1. How are the images in fig.4 taken?
   2. How are the measurements for comparison made?
   3. Material used?
4. State the limitations of the approach presented, and some insights on how this can be applied to other additive manufacturing techniques. 

Author Response

Thank you very much for your review comments. Please find our response at the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

In this paper, the authors explore the collection of process data/knowledge from a type of material jetting process in order to improve the control and precision of the process. Overall, the paper is excellent and the work is a novel contribution to the literature. The manuscript is interesting to read and the figures are generally clear and useful. However, I have some suggestions for improvement that the authors should consider before publication. I support acceptance of the manuscript after a minor revision to address my comments. 

1. There are good discussions in this paper about extracting and using manufacturing knowledge to improve process performance and better ensure manufacturability, as well as optimization of printing patterns. However, there is not much discussion of the actual manufacturability constraints that would be needed to accomplish this. The authors should address this, at least conceptually. If identifying specific constraints is out of the scope of this paper, they should be discussed conceptually at the minimum.  

2. The term "thermoplastic 3-D printing" is used in several places. While the authors are referring to a specific process with this name, it could be confusing for readers. Material jetting processes are typically associated with thermosetting materials, as you know. I suggest that the term "thermoplastic" not be used in this context and the process you are referring to be called something else. 

3. There are a very large number of self-citations to the authors. As this is a research article and not a review or concept paper, this is probably not a good idea. I suggest that the authors should review these and remove any that are not truly necessary for the work. 

4. There are a number is non-English sources cited. This is fine if these were the sources of information and no English sources were available. JMMP is an English-language international journal and so every effort should be made to use sources that would be available and useful for the readership of this journal. If this is not possible, it would be helpful to put a note about this in each of the non-English sources. (This manuscript appears to have been written using LaTeX - you would simply need to add "note = {}," to the end of your BIBTEX entries to add this). 

5. Line 53-54: It is best not to talk about specific institutes or universities within a scientific paper. Simply describe the process and cite it if needed. 

6. The layout of Figure 1 can be improved dramatically (the individual panels are fine)

7. In Section 4, I would like to see more discussion of the potential error and uncertainties in the process and analysis method used. You do not need to do a formal analysis, but simply acknowledge the potential impacts and give some future work ideas for how to address these. 

8. Author contributions: Acquisition of funding is not a valid qualification for authorship, so this should be removed from the statement

9. Finding and acknowledgements sections should be combined and the only information given should be the grant number/title - this is an international journal and the other information is irrelevant to most of the readers 

 

Author Response

Thank you very much for your review comments. Please find our response at the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Title:   Process data-based knowledge discovery in additive manufacturing of ceramic materials by Multi Material Jetting (CerAM MMJ)

 Reviewer

The topic is of great interest in structural engineering and falls within the scope of “Journal of Manufacturing and Material Processing”.

The article is worthy to be published. However, I suggest the paper revision which should be performed taking into consideration the comments, as indicated in the following.

Comments

1. Introduction - The reviewer suggests to upgrading the current state of research adding references of recent years. For example, the following works are suggested: https://doi.org/10.1016/j.compstruct.2017.11.029 ; https://doi.org/10.1016/j.compstruct.2017.09.049 . Please, also mention any articles of this jmmp MDPI.
2. The reviewer suggests to expand the characters of Figure 3a, to facilitate the reader.
3. Lines 47, 53, 57, 66, 74, 78 and so other - In the text, bibliography references must be preceded by a space and placed before the full stop of the sentence, in accordance with the author instruction. Please, check throughout the article.

Author Response

Thank you very much for your review comments. Please find our response at the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

Focusing on the process step of green part production for Multi Material Jetting, a data management plan was developed using an engineering workflow. Te results show that identification of key parameters such as falling time, needle lift, rising time, or air supply pressure, permit an optimization of the droplet geometry according to the introduced targeted characteristics. I recommend addressing the following aspects before publication:

Fig. 2 may be included in the introduction since is part of the state-of-the-art.

Figure 7.a does not present variations as a function of the studied parameters. This should be explained and the scale modified if necessary.

„Multi Material Jetting enables the additive manufacturing of ceramics, metals, glass and hardmetals, demonstrating comparatively high solids contents of the processed materials.“ . “Though the shape of polymers is well mastered by the available AM methods, the adaptation to  metallic and ceramic masses is subject to several challenges.” -The recent advances in tailoring materials to the process of additive manufacturing should be briefly discussed in the introduction: e.g. see  Peritectic titanium alloys for 3D printing, Nature Commun.

“Figure 3. (a) Technological process chain for the production of a part using CerAM MMJ”. The characters in this figure are hardly readable (especially in a). Moreover, the explanation of the full processing chain is too long in the manuscript since the focusing on the results in only the green part production. The focus should be more settled in the novelty of the results obtained.

Can the results obtained be applied to any type of powder (E.g. Metal or ceramics)? The link between the results and the materials used for 3D printing should be discussed.

“self-sufficient analysis methods, such as machine learning concepts, will have to be implemented with an extended scope of sensor technology”. Can the authors speculate how can the results obtained be used for this purpose?

Author Response

Thank you very much for your review comments. Please find our response at the attachment.

Author Response File: Author Response.pdf