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 Intelligent wheelchairs, predictive prostheses
20.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

nachricht Jelly with memory – predicting the leveling of com-mercial paints
15.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

Im Focus: The Future of Ultrafast Solid-State Physics

In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.

Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...

Im Focus: Stronger evidence for a weaker Atlantic overturning

The Atlantic overturning – one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards – is weaker today than any time before in more than 1000 years. Sea surface temperature data analysis provides new evidence that this major ocean circulation has slowed down by roughly 15 percent since the middle of the 20th century, according to a study published in the highly renowned journal Nature by an international team of scientists. Human-made climate change is a prime suspect for these worrying observations.

“We detected a specific pattern of ocean cooling south of Greenland and unusual warming off the US coast – which is highly characteristic for a slowdown of the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

New capabilities at NSLS-II set to advance materials science

18.04.2018 | Materials Sciences

Strong carbon fiber artificial muscles can lift 12,600 times their own weight

18.04.2018 | Materials Sciences

Polymer-graphene nanocarpets to electrify smart fabrics

18.04.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>