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 New technology for ultra-smooth polymer films
28.06.2018 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

nachricht Diamond watch components
18.06.2018 | Schweizerischer Nationalfonds SNF

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Unraveling the nature of 'whistlers' from space in the lab

15.08.2018 | Physics and Astronomy

Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide

15.08.2018 | Earth Sciences

Early opaque universe linked to galaxy scarcity

15.08.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>