Using 3D printed plastic molds for injection molding of plastic parts in low volumes delivers large cost and time savings over traditional metal molds.
The use of 3D printed molds for injection molding instead of for instance aluminium molds, the production cost of the tools can be reduced by a factor of 20 from typically about 11-12,000 EUR to less than 500 EUR. This is documented through a development partnership between PLM Group and the Danish Hillerød-based plastics manufacturer Vilecon.
PLM Group estimates that the use of 3D printing for injection molding tools will spread explosively among more industries during the next few years, and Vilecon is just one of several Nordic companies that have begun using the method.
Development Manager Karsten Videbæk, Vilecon highlights their experience: “It is a very exciting technology. During the process with PLM Group we learned a lot which convinced me that there are great future perspectives in the use of 3D printed tools in the plastics industry.”
Although 3D printing, also known as Additive Manufacturing (AM), can often be used as an alternative to traditional injection molding, it is not always possible to directly 3D print plastic parts with the needed characteristics such as surface texture and colors. Therefore, it may be necessary to injection mold the items, but it is often quite expensive to get started because the initial manufacturing costs of the molding tools are high.
”This means that there is a risk that many good ideas end up in the drawer and development projects are often are discarded at an early stage. Furthermore companies are normally cautious when investing in metal tools for projects where only a few parts are needed,” explains Application Engineer Kurt Due Petersen, PLM Group.
Rapid, economic molds with 3D printing
It is significantly faster, less expensive and more flexible to produce tools using AM. This makes it more attractive to embark on the development and production of new and innovative parts in smaller series. The plastic inserts are printed in a specialized technical plastic material, which can be used for injection molding at very temperatures.
”Many companies that manufacture injection molded products can benefit from the use of Additive Manufacturing. It takes 24 to 48 hours to produce a fully production ready tool compared to having to invest thousands of Euros in a costly aluminium tool and wait days, weeks or months for it to be delivered,” explains Kurt Due Petersen.
“Using overseas suppliers for your injection molding tools can also mean very long lead times, which can affect your go to market plans.”
”An additional advantage of using 3D printing for the production of inserts is that it is very flexible and makes it easy to try out different design alternatives to achieve the optimal end product.”
3D printing resuscitates abandoned project
Vilecon has used the technology to manufacture tools for injection molding of small electronics boxes. The boxes will contain temperature and humidity sensors as well as a small SIM card module for communication and will be used for remote monitoring of the temperature and humidity in Swedish churches in order to optimize the energy consumption.
The project had been shelved for several years because it was not economically feasible to buy a molding tool in metal, nor was it possible to 3D print the finished items in the desired material.
The development of the 3D printed mold has been a process together with PLM Group. During an iterative process they tested a number of design options to get even the small design details in the part exactly right. The knowledge sharing with PLM Group has overcome the technical challenges in using the new process and the parts are now ready for use.
Turnkey 3D printing solution
“Throughout the process we have documented all the lessons learned. This goes about getting the part design ready for print, about the structure of the tool to get the success rate as high as possible, and last but not least: How to adjust the injection molding machine correctly to take into account that the mold is made from the special plastic material,” explains Kurt Due Petersen.