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 TUM Agenda 2030: Combining forces for additive manufacturing
09.10.2019 | Technische Universität München

nachricht Copper oxide photocathodes: laser experiment reveals location of efficiency loss
10.05.2019 | Helmholtz-Zentrum Berlin für Materialien und Energie

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Highly charged ion paves the way towards new physics

In a joint experimental and theoretical work performed at the Heidelberg Max Planck Institute for Nuclear Physics, an international team of physicists detected for the first time an orbital crossing in the highly charged ion Pr⁹⁺. Optical spectra were recorded employing an electron beam ion trap and analysed with the aid of atomic structure calculations. A proposed nHz-wide transition has been identified and its energy was determined with high precision. Theory predicts a very high sensitivity to new physics and extremely low susceptibility to external perturbations for this “clock line” making it a unique candidate for proposed precision studies.

Laser spectroscopy of neutral atoms and singly charged ions has reached astonishing precision by merit of a chain of technological advances during the past...

Im Focus: Ultrafast stimulated emission microscopy of single nanocrystals in Science

The ability to investigate the dynamics of single particle at the nano-scale and femtosecond level remained an unfathomed dream for years. It was not until the dawn of the 21st century that nanotechnology and femtoscience gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished.

Ultrafast microscopy studies entirely rely on detecting nanoparticles or single molecules with luminescence techniques, which require efficient emitters to...

Im Focus: How to induce magnetism in graphene

Graphene, a two-dimensional structure made of carbon, is a material with excellent mechanical, electronic and optical properties. However, it did not seem suitable for magnetic applications. Together with international partners, Empa researchers have now succeeded in synthesizing a unique nanographene predicted in the 1970s, which conclusively demonstrates that carbon in very specific forms has magnetic properties that could permit future spintronic applications. The results have just been published in the renowned journal Nature Nanotechnology.

Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties – for example,...

Im Focus: Electronic map reveals 'rules of the road' in superconductor

Band structure map exposes iron selenide's enigmatic electronic signature

Using a clever technique that causes unruly crystals of iron selenide to snap into alignment, Rice University physicists have drawn a detailed map that reveals...

Im Focus: Developing a digital twin

University of Texas and MIT researchers create virtual UAVs that can predict vehicle health, enable autonomous decision-making

In the not too distant future, we can expect to see our skies filled with unmanned aerial vehicles (UAVs) delivering packages, maybe even people, from location...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

Self-driving microrobots

11.12.2019 | Materials Sciences

Innovation boost for “learning factory”: European research project “SemI40” generates path-breaking findings

11.12.2019 | Information Technology

Molecular milk mayonnaise: How mouthfeel and microscopic properties are related in mayonnaise

11.12.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>