Freeform Injection Molding: The next generation of injection molding

Prototyping is the starting point of the innovation cycle. In an age where new innovations pop up every other minute, 3D printing has established itself as one of the most popular prototyping techniques. But have you ever considered injection molding for prototyping? In our conversation with Lasse Staal, CEO and co-founder of Danish company, Addifab we discussed their transformative prototyping technique of Freeform Injection Molding (FIM) which has enabled production of prototypes using injection molding.

“The 3D-printing industry has made significant developments in advancing additive manufacturing and it is getting quite popular for prototyping and low volume productions. We at Addifab were looking at using 3D-printing to fix a key flaw in the injection molding value chain - The expensive tooling requirement and the infeasibility of low volume productions,” began Lasse.

Injection molding is a highly efficient method for manufacturing high volume parts. But it has a well-known limitation. "The tool can be expensive and time-consuming, particularly when redesigns are required," continued Lasse. FIM is overcoming these challenges by making injection molding sustainable for low volume production and prototyping.

Combining best of both worlds

In response to those limitations, Addifab developed Freeform Injection Molding (FIM), which combines the short lead-times, low start-up costs, design flexibility and intricacies of 3D printing with the accuracy, versatility, and superior finish of injection molding. In FIM, soluble molds are 3D printed according to the required geometries, and the soluble molds enable production of complex parts, previously only possible through 3D printing.

Addifab is pioneering the development of soluble injection mold tools. “We have developed a mold material which incorporates three key elements required for the enhancement of injection molding. The material has high mechanical stability, high thermal stability and high solubility,” explained Lasse.

Fast, cost-effective, and flexible

FIM is a three-step process, kicked off by printing the soluble resin injection mold with a liquid resin-based 3D printer that UV cures with tolerances up to 10-50 μm. The printing resin is manufactured by Addifab inhouse and is suitable for a wide array of materials. One can choose between two types of resins, depending on the type of application (medical versus non-medical).

Next comes the injection phase. This occurs at a pressure of up to 2.500 bar and a melt temperature of up to 450°C. The mold can work with all standard materials such as thermoplastics, composites, ceramics, and metals. The final step in the process is where the soluble injection mold is dissolved over a period of 1-2 days instead of the conventional step of ejecting the part from the tool.

Environmentally conscious solution

We asked Lasse about the environmental impact of the soluble resin. He answered, “In order to analyze the environmental impact of our molds, we have to look at it from a different angle. I look at what we are replacing right now. Together with Deloitte Denmark, we conducted a life cycle analysis of a printed mold and a conventional mold. By printing the mold, the resources used have been reduced by 75%. In some cases, it may be even more. Printing the tools is an environmentally friendly solution. Eventually, you will still migrate to conventional tooling and the costs start to creep up. The advantage of using FIM for prototyping is having 100% certainty of verifying the design of the final product.”

Companies have almost standardized 3D printing for prototyping. The disadvantage of 3D printing becomes evident when you reproduce the same part in an injection mold. "You risk that the final mold isn't accurate, and that you produce defective parts and molds, which is quite environmentally costly, if you don't prototype using injection molding." continued Lasse.

Startups can benefit from FIM

FIM is a great way for startups to prototype with certain materials that are hard or even impossible to 3D print. This is especially relevant for companies that want to eventually scale up their production. “We have a couple of customers who started their business based on FIM. So, it is quite fascinating for us to see companies that wouldn’t have existed without our technology,” explained Lasse.

Addifab has also started offering their FIM service for personal applications. They collaborated with and manufactured a prosthetic glove for a world class Paralympic table tennis player. With FIM, Lasse and his team manufactured a lightweight, high-performance glove with high strength and high stiffness, unachievable by direct 3D printing. 

Another impressive use case of FIM is that of a startup manufacturing clothing buttons made from 100% recycled fishing nets. Finisterre, a UK based company are producing 3D printing filament and injection molding pellets out of this recycled material. In order to scale production, the company needed to shift from 3D printing towards injection molding. This is where Addifab supplied them with their technology and helped them scale production at an attractive budget.

FIM at Mitsubishi Chemical Group

Mitsubishi Chemical offers customers, the option of prototyping using Freeform injection Molding. The technology, known as SPRINT (Soluble PRinted INjection Tooling ), uses Addifab’s technology to offer a high flexibility in production of prototypes with the material that would be eventually used during scaling of production. This technology can be found at Mitsubishi Chemical Advanced Material’s manufacturing facilities in Belgium, USA and Japan. With the SPRINT technology, customers have access to CNC machining, 3D printing tooling, metal injection molding, all under one roof.

The journey ahead

We asked about Lasse’s vision of Addifab for the future. Lasse answered, “Addifab in 2022 is in a very good position to start expanding the scope of offerings and internationalization by partnering with other companies with the same goals. We are collaborating with the Mitsubishi Chemical Group by supporting the deployment of FIM as a service. With our recent collaboration with Nexa3D, we can now support a wider scope of applications. So far, we have demonstrated the applicability of FIM in several applications such as manufacturing of medical devices, drone components, automotive parts and other customized applications which can be produced in a batch of 1.”

Addifab is positioned well to support developers, entrepreneurs and innovators who are striving for more sustainable, cost efficient and flexible product development. 

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