As part of the research project “ULAS-E-VAN” (“UltraLeicht AufbauStruktur eines Elektrischen VANs” – UltraLightweight Body Structure of an Electric VAN), nine partners are developing lightweight solutions for the body structure and a modular battery carrier system of battery-electric powered light commercial vehicles ( commercial vehicles, class N1 – Ford Transit – BEV). Ford is coordinating the research project with a total volume of 5.8 million euros, funded by the German Federal Ministry of Economics and Climate Protection (BMWK). The project partners are Altair Engineering GmbH, BENTLER Automobiltechnik GmbH, C-TEC GmbH, Ford-Werke GmbH, Franken Guss GmbH + Co. KG, MORPHOTEC, RWTH Aachen University, Chair and Institute for Structural Mechanics and Lightweight Construction (SLA), RWTH Aachen University, Institute for Automotive Engineering (ika), and voxeljet AG.

If a light commercial vehicle is equipped with an electric drive, the empty weight increases due to the high battery weight and the possible payload decreases. To counteract this, it is imperative to decisively reduce the weight, especially in battery-powered delivery vehicles, through lightweight construction measures. Lightweight construction makes it possible to increase the range, but also to reduce the battery size, secondary weight and thus battery costs while keeping the range unchanged. However, in the targeted sector of e-commercial vehicles, the need for cost-effective lightweight construction is even more critical due to the high-cost sensitivity of the potential customer base and the relatively low unit numbers.

This is where the project comes in. The consortium aims to develop ultra-lightweight solutions for the body and superstructure of such battery-electric light commercial vehicles using modern CAE methods such as “simulation-driven design” and innovative manufacturing methods. In addition to a special 3D printing process – 3D sand mold printing – to produce molds for the iron casting process, large-format structural plastic parts are also used.

The design of the body structure is to be based on a frame-stringer construction, thus transferring the proven aircraft construction method to light commercial vehicle construction with higher annual production figures. The frames are to be designed as a single piece wherever possible and in a bionic-optimized manner. The outer skin will be formed by prefabricated plastic panels that are connected to the load-bearing structure. A load-bearing, ultra-lightweight, scalable and modular battery support system is to be integrated in the underbody, which will provide functional support for the body structure in terms of stiffness, fatigue strength and crash. The technologies used are expected to achieve weight savings in the order of up to 150 kg on a total vehicle level, thus enabling an increased range or payload.

Alongside the standard polymer PA12, TPU is one of the polymers increasingly in demand for 3D polymer printing. With its cushioning properties, the thermoplastic material has proven itself for decades in the production of shoe soles, it offers impact protection and is being used more and more across industries: in the plastics processing industry, in the automotive and consumer goods industry, in aerospace and in the engineering sector.

In the production of polymer components, voxeljet takes advantage of the special material properties of TPU in conjunction with the HSS technology: TPU can be very soft and elastic or very hard and persistent. These properties can be specifically influenced in all three dimensions using HSS technology. In High Speed Sintering, a fine layer of polymer powder is applied onto a heated build platform and the areas where the part is to be built are then inked with a heat-absorbing ink. Infrared light is used to fuse the printed areas of the polymer powder, leaving unprinted material loose. Layer by layer, the polymer is applied, printed, and irradiated until the build-up of the full jobbox and the parts within it, is complete. How soft or solid the part is depending on the volume of infrared-absorbing ink introduced. The more heavily a build area is inked, the stronger the part. By using industrial inkjet print heads, it is possible to print correspondingly different gray levels within a layer and thus realize different product properties per layer. In addition to this grayscale printing, the strength of a component can also be influenced by its geometry. Lattice structures with different wall thicknesses are used to print geometries that can be adapted to individual load profiles in order to save additional material.

“The HSS technology in combination with the TPU material allows us to provide an inherently hard, highly stressable part with soft properties. This opens up completely new and highly individual application possibilities of 3D printing for plastic parts,” says Tobias Grün, Global Product Manager at voxeljet. TPU components produced with the HSS printing process have particularly long-lasting permanent elasticity and excellent rebound properties compared to other TPU 3D printing processes. The successfully passed Cytotoxicity test also confirms that there is no damage to cells and tissue when the material comes into contact with the skin. In addition, no discoloration of the components occurs. “With the HSS process, we can produce individualized polymer parts on-demand at high quality and speed at comparatively low cost. High Speed Sintering is an economical, efficient and resource-saving solution due to the use of large-format print heads. The technology offers enormous potential for future-oriented products,” says Tobias Grün.

The TPU qualified for the HSS technology was co-developed by voxeljet and materials manufacturer Covestro. “The close cooperation between material and machine manufacturers enabled us to bundle our joint know-how and thus coordinate and optimize the part quality as well as the 3D printing process.” says Grün. With the collaboration, the two companies aim to develop integrated material and process solutions for the economical additive high-volume production of polymer components.

To the extent this document contains forward-looking statements, such statements are not statements of fact and are made using words such as “expect”, “believe”, “estimate”, “intend”, “strive”, “assume” and similar expressions. These statements are an expression of the intentions, views or current expectations and assumptions of voxeljet AG and are based on current plans, estimates and forecasts made by voxeljet AG on the basis of its best knowledge, but do not constitute any statement with respect to their future accuracy. You should not place undue reliance on these statements. voxeljet AG cannot provide assurances that the matters described in this press release will be successfully completed or that voxeljet AG will realize the anticipated benefits of any transaction. Forward-looking statements are subject to risks and uncertainties, which are usually difficult to predict and ordinarily not in the domain of influence of voxeljet AG. These risks and other factors are discussed in more detail in the company’s public filings with the SEC. It should be noted that actual events or developments could materially differ from the events and developments described or included in the forward-looking statements. Statements made herein are as of the date hereof and should not be relied upon as of any subsequent date. The company disclaims any obligation to update any forward-looking statements except as may be required by law.

The sale-leaseback transaction involving the Company’s 135,380 square foot facility in Friedberg, Germany, was entered into with an institutional, unaffiliated real estate investor, and is subject to regulatory approvals in the Federal Republic of Germany. The leaseback of the facility provides for a fifteen-year lease commitment with two consecutive five-year extension option periods.

The Friedberg facility serves as voxeljet’s headquarters as well as its center of excellence for research, development and production of the Company’s 3D printing systems.

This press release contains forward-looking statements concerning our business, operations and financial performance. Any statements that are not of historical facts may be deemed to be forward-looking statements. You can identify these forward-looking statements by words such as ‘‘believes,’’ ‘‘estimates,’’ ‘‘anticipates,’’ ‘‘expects,’’ ‘‘projects,’’ ‘‘plans,’’ ‘‘intends,’’ ‘‘may,’’ ‘‘could,’’ ‘‘might,’’ ‘‘will,’’ ‘‘should,’’ ‘‘aims,’’ or other similar expressions that convey uncertainty of future events or outcomes. Forward-looking statements include statements regarding our intentions, beliefs, assumptions, projections, outlook, analyses or current expectations concerning, among other things, the projected timing and successful completion of the sale-leaseback transaction, our results of operations, financial condition and business outlook, the industry in which we operate and the trends that may affect the industry or us. Although we believe that we have a reasonable basis for each forward-looking statement contained in this press release, we caution you that forward-looking statements are not guarantees of future performance. All of our forward-looking statements are subject to known and unknown risks, uncertainties and other factors that are in some cases beyond our control and that may cause our actual results to differ materially from our expectations, including those risks identified under the caption “Risk Factors” in the Company’s Annual Report on Form 20-F and in other reports the Company files with the U.S. Securities and Exchange Commission. Except as required by law, the Company undertakes no obligation to publicly update any forward-looking statements for any reason after the date of this press release whether as a result of new information, future events or otherwise.

The process is the perfect combination of two established production methods. A roll-bonded core (RoBoC) is inflated on one or both sides with approx. 100 bar compressed air to create cooling channels of the usual dimensions. This core is placed in a permanent mold and aluminum is cast around it. During the casting process, temperature is controlled from the inside through the existing channels so that deformation or melting is prevented. The result is a metal sheet integrated into the housing with the structures required for cooling the E-machine.

The cooling channel layout can be represented in a helical shape. Thus, the hottest channel section is embedded between the coldest and second coldest channel sections. The result is a homogeneous temperature distribution without a hot spot during engine operation. This design cannot be represented in the classic 2-shell design (e.g. in die casting), since there would be a thermal short circuit due to overflow from one channel section to the other. Depending on the customer’s requirements, however, meander-shaped or flat duct layouts can also be realized. Sealing against cooling water leakage is ensured by means of the self-contained roll bond core and is therefore no longer dependent on the casting quality. An expensive helium leakage test on the finished part, which can result in a very high loss of added value, is no longer necessary. Assembly, as required with the 2-shell design, is completely eliminated.

AionaCast has provided proof of concept by means of “proof of concept”. Little attention was paid to the cross-sections for the cooling medium and weight reduction. Now the team is working on Generation 2, where the inserted and inflated sheet is in direct contact with the stator, which again increases efficiency and reduces weight.

This concept makes it possible to reduce the wall thickness between the stator and the water-bearing channel from about 5 to as little as 1.5 mm. This reduction in wall thickness is also reflected in the overall weight of the electric motor housing for a typical BEV traction motor, which is reduced by approximately 1 kg.

Furthermore, the response time from the interaction of the optimizations is significantly reduced. To present the performance of the system, a CFD simulation of an existing traction motor from a major OEM was compared to the RoBoC Gen2 development. The time for the temperature reduction from 60° to 40°C in the stator could be reduced by about 70%. A pleasant side effect is also the significantly reduced casting process time, where the time to component removal from the casting mold can be significantly reduced due to direct cooling of the aluminum casting from the inside.

• The helix design and the smaller distance between stator and cooling medium results in higher thermal efficiency.
• The tightness of the cooling water channel is independent of the casting quality. Due to the concept, seals are completely eliminated and there is no residual dirt problem due to the absence of core sand. This makes this innovation more reliable than conventional systems.
• To list just a few cost advantages, such as the elimination of assembly (2-shell design), the lack of a sand core eliminates the need for reworking and capping of the core marks, several quality tests are no longer required, and the non-negligible shorter casting cycle makes the invention competitive.

For further development (prototypes), the patent holder AionaCast, which is also responsible for project management, was able to win well-known partners for the modification of a Bosch series housing:

• Kupral S.p.A. (Italy) / casting technology
• voxeljet AG (Germany) / 3D-printed molds for core package
• LPM S.p.A. (Italy): Foundry equipment
• Peter Prinzing GmbH (Germany): Roll-bond bending

In view of approximately 75 million traction electric motors to be produced from 2030, Jürgen Pohl sees further business development for this new manufacturing process as extremely positive. Furthermore, the same manufacturing concept with modified cooling channel layout (e.g. meander-shaped, flat or parallel channels) also offers potential for the production of battery and power electronics housings, he said.

The VX200 HSS from voxeljet is designed as an open source 3D printing system and provides full access to process parameters and temperature management to best match the additive manufacturing process and material. The HSS Material Network offers customers a flexible and low-risk outsourcing option for material development of additive manufacturing technologies. The addition of the competencies of the HSS Material Network partners enables companies of all sizes to receive unique support, from an initial suitability assessment, through specific development and parameterization, to certification or market-ready qualification of the material. Here we present our partners, projects and proof of concepts.

The iglidur® i3 material is a plastic powder specially developed by igus® GmbH for the production of gliding applications and gears for the additive processes of Powder Bed Fusion of Polymer (PBF-P), such as laser sintering (LS). It is used to manufacture components with a wide variety of applications, for example as special sliders in passenger cars, as gear wheels in e-bikes and even as sliders in elevators.

The special feature of iglidur® i3 PL is the additivation of the powder with solid lubricants, whereby the components manufactured from it achieve a wear resistance that is better by a factor of 3 to 30 than components manufactured from plastic powders otherwise available on the market. For this purpose, a large number of different formulations were tested and developed in the igus laboratory in Cologne. In addition, the service life of iglidur® i3 gears and plain bearings has become calculable online due to the large number of tests. Customers can thus check the properties of the components in advance for their performance and service life in order to make any design adjustments before the final production.

Due to its print head technology, the HSS has the potential for a significantly more economical production than the LS. Moreover, thanks to its open-source conception, HSS has the possibility to specifically adjust component properties on the process side, and thus offers great potential for many applications of the components made of iglidur® i3.

In addition to the high abrasion resistance, iglidur® i3 also stands out as a very good gear material. In numerous tests, the good suitability as gear material could be proven and confirmed by igus. Many times better than gears made of PA12 and PA11 in LS and even better by a factor of 5 than conventionally manufactured gears made of POM.

The iglidur® i3 material has already been available for the PBF-P since 2016. By means of LS, more than 400,000 components have already been manufactured with it. The plain bearings and gears manufactured by the project group Process Innovation of the Fraunhofer IPA and the Chair of Environmentally Friendly Production Technology of the University of Bayreuth within the scope of the proof of concept in HSS exhibit very good mechanical properties, which make a further optimization of the material to the HSS process up to a full qualification quite interesting.

igus is one of the recognized experts when it comes to polymers for sliding applications. 3D printing is not a novelty for the company. For example, the iglidur® i3 PL material was already qualified for laser sintering processes in 2016 and over 400,000 components have been manufactured with it to date. By means of HSS, the material can be processed even more economically. The reason for this is the high productivity and reproducibility of the HSS process.

The VX200 HSS from voxeljet is designed as an open source 3D printing system and provides full access to process parameters and temperature management to best match the additive manufacturing process and material. The HSS Material Network offers customers a flexible and low-risk outsourcing option for material development of additive manufacturing technologies. The addition of the competencies of the HSS Material Network partners enables companies of all sizes to receive unique support, from an initial suitability assessment, through specific development and parameterization, to certification or market-ready qualification of the material. Here we present our partners, projects and proof of concepts.

HDPE is a high-density polyethylene (0.94-0.97 g/cm³) and is particularly characterized by its very good resistance to chemicals and greases as well as its water-repellent effect. At room temperature, HDPE has a hard yet flexible appearance and, in addition to its very good mechanical properties, has good sliding behavior and increased wear resistance.

HDPE is therefore used, among other things, for the manufacture of products for the food and packaging industries, especially for the chemical industry. Thus, containers, bottles and pipes for chemicals, fuels, water, gas or oil are manufactured from HDPE as standard.

The process window of HDPE is very small for processing in laser sintering and, furthermore, a high laser power is required to melt the powder particles. The mechanical properties of the HDPE are negatively influenced by the high thermal load due to the punctual or line-by-line exposure by laser. This results in embrittlement of the material.

In the case of HSS, on the other hand, the energy is applied to the powder bed surface by means of an infrared lamp with the aid of an ink, which is selectively applied to the powder bed surface via a print head. The two-dimensional exposure ensures that the duration of the energy input is significantly longer compared to laser-based production systems. As a result, significantly lower maximum temperatures can be realized, which reduces thermal stresses on the material and preserves the proven mechanical properties of HDPE.

Unlike PA12, HDPE is a pure hydrocarbon. This makes HDPE non-polar, water-repellent and highly resistant to chemicals. At room temperature, HDPE is therefore not attacked by many solvents, alkalis and acids. Similar to PA12 or PP, up to 100% of the unprinted powder can be reused.

With respect to PP but also to PA12, HDPE offers a significant price advantage, as HDPE is a widely used mass plastic which is much cheaper to produce than PA12 or PA11. In addition, HDPE is manufactured in Europe, which secures supply chains and times.

The proof of concept was manufactured from the HDPE powder DiaPow HDPE HX developed by Diamond Plastics GmbH for laser sintering, which is characterized by a very uniform particle size distribution and very good flowability. The process capability analysis and initial parameterization carried out by the Fraunhofer Project Group Process Innovation of the Fraunhofer IPA and the Chair Manufacturing and Remanufacturing Technology of the University of Bayreuth demonstrate that the HDPE powder has very good processability in HSS. Therefore, the HDPE powder will be optimized and fully parameterized by the partners specifically for the HSS process. The focus will be on reproducibility, part quality and productivity in terms of reduced shift time. Finally, the adapted HDPE powder is made commercially available to the market.

Particularly noteworthy is the fact that a particularly high degree of flexibility was achieved during processing using HSS. This kind of flexibility is difficult to achieve in laser sintering, for example. The reason for this is the selective thermal loading of the material. This has a negative effect on the mechanical properties of the material. With HSS, on the other hand, the powder bed is exposed over a large area, which increases the duration of the energy input and reduces thermal stress. In this way, the flexibility of the HDPE is retained.