Hybrid manufacturing marries material and design freedom
An EU-funded project has demonstrated a unique hybrid manufacturing technology combining the freedom of 3D printing design with the low-cost, reliability and materials diversity of injection moulding. The innovation bridges the costly, risky and time-consuming gap between prototyping and commercial production for everything from medical devices to aircraft components.
© AddiFab, 2019
Smart technology like 3D printing is ideal for prototyping new product designs, using additive manufacturing to build up complex parts and intricate geometric shapes layer by layer. However, it only works with a limited number of materials.
Injection moulding, in which moulds are filled quickly, cheaply and reliably to create thousands or millions of identical parts, is a well-established manufacturing technology that can be used with many different types of materials. These include pre-qualified, specialised material grades for automotive and aerospace applications, and standardised, certified materials used in dental implants or medical devices that must be biocompatible.
However, injection moulding is hampered by high start-up costs, long lead times and limited freedom to incrementally improve designs through repeated, iterative processes. Such drawbacks are a particular challenge in metal and ceramic injection moulding, where multiple tooling attempts are usually needed to achieve the desired results.
Thanks to the EU-funded STIM-MC project, Freeform Injection Molding (FIM), a proprietary technology developed by Danish start-up AddiFab is being further enhanced to produce a process which is up to 5 to 10 times faster and cheaper in delivering injection-moulded prototypes. This is a game-changer for manufacturers, especially firms producing small, complex and high-performance components for industries such as healthcare, transport and aerospace.
Weve created a hybrid platform that harnesses the benefits of both 3D printing and injection moulding across the prototyping and manufacturing process, enabling a wider range of materials to be used from start to finish, including metals and ceramics, as demonstrated in STIM-MC, says project manager Uffe Bihlet at AddiFab.
3D printing is great for making initial prototypes, but significant problems can arise in transitioning a new design to large-scale manufacturing via injection moulding when a different material and a different process must be used, for instance for strength, durability or safety reasons. This transition to injection moulding typically entails new validations and extra time, costs and risk, Bihlet explains.
AddiFabs FIM system solves these problems by allowing the same material and the same injection moulding process to be used for both the prototype and the finished product, without restricting the design versatility afforded by 3D printing.
From CAD to cavity
The FIM process begins with a conventional CAD file containing the designs for a new component. The system inverts the design to create a cavity which is then encased in a mould body made from proprietary dissolvable resins via 3D printing. The 3D-printed mould is then transferred to the injection-moulding machine which uses the cavity to form the part following standard injection moulding manufacturing processes.
The mould cavities are strong enough to process reinforced thermoplastic polymers and other high-performance materials. And, being made from dissolvable resins, single-use moulds enable the production of components with highly complex shapes and features.
In STIM-MC, the project partners successfully demonstrated the vast range of potential applications for the technology, testing it with a large number of materials and additives, particularly metals and ceramics that require additional processing, tooling and finishing steps compared to plastics.
The trials conducted in STIM-MC demonstrate the versatility of the FIM platform across a diverse range of materials and applications in different industries, while raising awareness its value-creating potential among material suppliers, manufacturers and end-user customers, the project manager says.
Among new AddiFab partners is Mitsubishi Chemical which has an extensive portfolio of materials, including super-strong metal-replacement and carbon-fibre-based polymers. Many of these unique and innovative materials are not currently suitable for additive manufacturing via 3D printing, but can be used with AddiFabs FIM technology with high batch-to-batch consistency.
AddiFab plans to collaborate with Mitsubishi Chemical to deploy the FIM platform commercially as a gateway for product developers, opening the door to a wider range of material options. It will enable manufacturers to prototype new parts using novel materials quickly, cheaply and efficiently, while ensuring designs can be turned almost seamlessly into injection-moulded finished products ready for large-scale production.