Additive Surface Graining in Prototype Tooling for Injection Molding
Round 1
Reviewer 1 Report
The manuscript is of practical importance, and the research aim is achieved and supported by the results. However, I would recommend the authors to follow a more standard article’s structure (with the following sections: Introduction, Materials and Methods, Results, Discussion, Conclusions). Also, the abstract of the article is too general. I would recommend adding more concrete results of the research to it.
Also, the information about the equipment and software used is missing in the text (injection molding machine, CAD software used for the mold design, the equipment for roughness measurements, etc.).
When the authors assess the obtained results, they only state what they observe (differences of the roughnesses between the CAD model and the real mold). However, it would be interesting to see how they can explain what the cause of these differences is.
Author Response
Dear reviewer 1,
we would like to thank reviewers for their thoughtful comments. We are glad to hear that our main idea of using additive manufacturing of injection molds for creating parts with grained surfaces in prototype stages was appreciated and reviewers share the conception of it being a valuable contribution to the community.
Please find our responses to the comments below:
- Article structure
We would like to thank the reviewer for the suggestion on the article structure. We have changed the article structure to the following chapters:
- Introduction
- State of the Art
- Materials and Methods
- Results
- Discussion
- Conclusion
- Abstract
The abstract was modified and information that is more concrete added in lines 6-10.
- Information about equipment used
We have included information about the specific equipment used (injection molding machine, 3D printer and optical scanner) in order to improve replicability of our findings.
- Interpretation of difference of roughness between CAD model and printed injection mold
Our results show differences between CAD model, printed injection mold as well as resulting injection molded parts. We have included an additional explanation for the difference between CAD model and printed injection mold. “This is caused by the liquid-based additive manufacturing technology by means of jetting. The photopolymer cannot be cured instantaneously so that the photopolymer is subjected to gravity before curing which results in less sharp contours.”
Reviewer 2 Report
The author presented an interesting work. In order to obtain parts with surface textures, a four-cavity injection mold was obtained by 3D printing, wherein the four cavities have four different surface structures respectively. The roughness of the mold CAD model, the 3D printing mold, and the part was compared. The effect of different mold surface structures (structure distance and depth) on part roughness was investigated. I recommend the article publication in the Journal of Manufacturing and Materials Processing after major revision. Here are a few comments and suggestions that will improve the quality and clarity of the manuscript:
It is recommended to add the following research content:
- Influence of injection parameters on part roughness.
- Based on the research on the cavity and the part based on the surface structure and injection parameters, comprehensively analyze the reasons for the difference in roughness between the mold cavity and the part.
- Based on 2, a method for forming precision roughness parts is proposed and verified, such as considering melt shrinkage.
Modifications to existing content:
- The error bars in Figure 5 are not clear.
Author Response
Dear reviewer 2,
we would like to thank reviewers for their thoughtful comments. We are glad to hear that our main idea of using additive manufacturing of injection molds for creating parts with grained surfaces in prototype stages was appreciated and reviewers share the conception of it being a valuable contribution to the community.
Please find our responses to the comments below:
- Influence of injection parameters on part roughness
The process chain from a CAD model to injection molded parts with grained surfaces comprises of several steps with a lot of variables each. In order to keep the complexity of this study at a reasonable level in terms of effort for experiments, we had to focus on the process steps more related to additive manufacturing rather than injection molding. However, injection molding parameters are documented in chapter 3.2 Realization and Try-outs.
- Based on the research on the cavity and the part based on the surface structure and injection parameters, comprehensively analyze the reasons for the difference in roughness between the mold cavity and the part.
We have found that the surface structure of the printed injection mold could well be replicated on the injection molded parts with regard to their Ra values. This shown by similar Ra roughness values between the printed injection mold and the parts. We have added explanations for the difference in Rz roughness between the printed injection mold and the part as well as the difference in Ra values of the CAD model and the injection mold.
- Based on 2, a method for forming precision roughness parts is proposed and verified, such as considering melt shrinkage.
In our opinion this is a crucial finding. Being able to control the roughness and surface structure of an injection mold and injection molded parts is a massive benefit which is levered by additive manufacturing of injection molds. In this study we wanted to focus on the variables related to additive manufacturing of the injection mold. In the future we would like to include injection molding variables as well as different injection molding materials into the experiments in order to gain a more general validation of our approach.
- The error bars in Figure 5 are not clear.
We have increased line thickness and colour so that error bars are clearer.
Reviewer 3 Report
The proposed topic is innovative and original, but there are issues needing clarification (in the enclosed PDF file).
Comments for author File: 
Comments.pdf
Author Response
Dear reviewer 3,
we would like to thank reviewers for their thoughtful comments. We are glad to hear that our main idea of using additive manufacturing of injection molds for creating parts with grained surfaces in prototype stages was appreciated and reviewers share the conception of it being a valuable contribution to the community.
Please find our responses in the enclosed pdf.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
I recommend the article publication in the Journal of Manufacturing and Materials Processing
Author Response
Thank you for your much appreciated revision and recommendation for publication of our article.
Reviewer 3 Report
I could not see the detailed authors report, only few comments in the pdf file. I need the separate report with answer to all queries, and which modifications were made in the paper. Thank you
Author Response
Dear reviewer 3,
thank your very much for your review and thoughtful comments and suggestions. Please find a list of our modifications enclosed in the attachments.
Author Response File: Author Response.pdf
Round 3
Reviewer 3 Report
Thank you for providing the report. All my queries were positively answered. I recommend publication.
