3D-Printed Injection Molds

Abstract: This master thesis describes the development process of a prototyping process. It was carried out in collaboration with Axis Communications. When creating plastic prototypes, development engineers usually have two options, 3D-printing or injection molding using a soft tool. 3D-printing allows for fast and relatively cheap creation of prototypes which contributes to a fast product development process, but the physical properties are not the same as in the final product. Injection molding using a soft tool creates prototypes of high quality with physical properties equal to the final product, but it is time consuming and costly. The purpose of the project was to investigate the possibility of 3D-printing injection molds for prototyping and to create a process where the method is used. This would combine the two prototyping options into a process that would be situated between them, allowing faster prototyping than injection molding using a soft tool while also creating better quality prototypes than 3D-printing. Through external and internal research, including interviews and physical tests with an injection molder, a greater understanding of the subject was achieved and experience regarding the problems related to the process were identified. The information gathered was then turned into target specifications. To reach the target specifications multiple design concepts and mold materials were tested before a final selection was conducted. One mold material and eight design concepts were selected for the process. The design concepts solve different problems which can not be solved directly by the selection of mold material. The results are summarized as an instruction of how to use the process and a recommendation of how to further develop it.