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 Diamond watch components
18.06.2018 | Schweizerischer Nationalfonds SNF

nachricht Quick and safe laser joining of steel-aluminum mixed connections
05.06.2018 | Laser Zentrum Hannover e.V.

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Carbon nanotube optics provide optical-based quantum cryptography and quantum computing

19.06.2018 | Physics and Astronomy

How to track and trace a protein: Nanosensors monitor intracellular deliveries

19.06.2018 | Life Sciences

New material for splitting water

19.06.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>