Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

No compromises: Combining the benefits of 3D printing and casting

23.03.2018

Researchers at Fraunhofer IPA have developed a new process that combines 3D printing and casting. In additive freeform casting (AFFC), first a shell of the part is manufactured using FLM printing, then this shell is filled with a two-component resin. This saves time, increases stability of the part and allows new materials to be printed.

Additive manufacturing, also known as 3D printing, already presents a wide range of advantages for industry. IPA expert Jonas Fischer explains: »You enter the CAD data for a workpiece and receive a finished part.« Small batches, prototypes and individual pieces are all faster and more cost effective to manufacture than is the case with injection molding. Moreover, complex structures and integrated functionalities can be created. However, there are still some weak points.


In additive freeform molding, the shell of a part is constructed using FDM printing. A dosing unit in the printer then fills this with a two-component mixture.

Fraunhofer IPA/Rainer Bez


IPA researchers have proven the feasibility of the process and created several prototypes.

Fraunhofer IPA/Rainer Bez

Only three minutes to harden

With FLM (fused layer modelling) printing, the most widespread method, a nozzle deposits the printed material in parallel lines. This creates seams and porosities. Jonas Fischer adds: »The material is not completely in the form like it is when molded. This means that the component has worse mechanical properties.«

Furthermore, during FLM processes the nozzle applies each layer individually. It takes a long time for a large component to be constructed. A third disadvantage is that only plastics that become soft when heated (called thermoplastics) can be used with FDM printing. Thermosets, which remain stable after hardening regardless of any heat administered, cannot be printed.

With additive freeform molding, researchers at Fraunhofer have now found a way to keep these downsides to a minimum. To do this, they combined the additive process with a molding procedure. The first step is to manufacture the shell of the part via the FLM process. The experts use polyvinyl acetate (PVA), a water-soluble synthetic polymer, as the printing material.

Subsequently, the shells are filled automatically with a precisely dosed quantity of polyurethane or epoxy resin. With polyurethane, it only takes three minutes for the filling to be cured. Next, the number of components can be increased if desired. As soon as the process is complete and the part has hardened, the shape is removed and placed in a water bath. This creates a 3D-printed workpiece with the properties similar to those of an cast part.

Manufacturing »in one piece« is possible

In order to inject the filling material into the mold, IPA researchers installed a special dosing unit for two-component materials in the 3D printer. This means it is possible to perform the entire process – printing the shell and the filling – in one piece. The printing process does not have to be interrupted and can be controlled fully digitally as with conventional 3D printing.

Also, the procedure enables two-component resins to be used. Heat-resistant thermosets can be used as a construction material. Moreover, it is claimed that components can be manufactured much more quickly. Jonas Fischer adds: »You only need to print the shell – gravity does the rest of the work.« Last but not least, the components are reported to be significantly more stable as the material completely fills the form, so no porosities or air pockets occur.

The new method is suited for a variety of application areas and industries. Fischer explains: »for instance, it can be used for electrical isolation components like sockets. Foams and cushions, such as those needed for safety elements, are also suited to this procedure.« In principle, the combined freeform casting is said to always be the preferred option when large, complex components are required in small quantities. Moreover, it can help to reduce weight.

Seeking further development partners

IPA researchers have successfully proven the feasibility of this process in a pre-research project. Furthermore, they created various components as prototypes. Now the researchers are looking for industry partners to support them in further developing the process for series production. They are also seeking materials manufacturers to improve the properties of the two-component mixture together with researchers. Companies with ideas for various application areas of thermosets are welcome too.

Press communication
Ramona Hönl | Tel.: +49 711 970-1638 | ramona.hoenl@ipa.fraunhofer.de

Specialist contact
Jonas Fischer | Tel.: +49 711 970-1119 | jonas.fischer@ipa.fraunhofer.de

Jörg Walz | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA
Further information:
http://www.ipa.fraunhofer.de/

More articles from Process Engineering:

nachricht A water treatment breakthrough, inspired by a sea creature
27.11.2018 | Yale University

nachricht Research project AutoAdd: Paving the way for additive manufacturing for the automotive industry
22.11.2018 | Fraunhofer-Institut für Lasertechnik ILT

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data storage using individual molecules

Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.

Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

When a fish becomes fluid

17.12.2018 | Studies and Analyses

Progress in Super-Resolution Microscopy

17.12.2018 | Life Sciences

How electric heating could save CO2 emissions

17.12.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>