voxeljet AG (NASDAQ:VJET) is expanding its portfolio of on-demand 3D printing services. Effective immediately, the company is offering on-demand components in the high-speed sintering (HSS) process also made of thermoplastic polyurethane (TPU). The flexible material is characterised by permanent elasticity, damping properties and high impact protection.
The TPU components are used in particular in the shoe industry, for padding in helmets, saddles or seats, for elastic pipes and hoses as well as for sealing and packaging. The TPU material used in the HSS process was developed by voxeljet together with the materials manufacturer Covestro. Customers benefit from customised polymer components in high quality at cost-effective prices.
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.
Different degrees of hardness through HSS process
In the production of polymer components, voxeljet takes advantage of the special material properties of TPU in combination with the HSS process: TPU can be very soft and elastic or very hard and durable. These properties can be specifically influenced in all three dimensions with the help of HSS technology. In high-speed sintering, a fine layer of polymer powder is applied to a heated building platform and the areas of the component are then wetted 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 exposed to light until the construction of the component is complete. How soft or solid the component is depends on the volume of infrared-absorbing ink introduced. The more an area of the component is inked, the stronger the component is. By using industrial inkjet print heads, it is possible to print different greyscales within one layer and thus realise different product properties per layer. In addition to this greyscale 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.
Durable elasticity at attractive on-demand prices
"The HSS process in combination with the TPU material enables us to provide an inherently hard, highly stressable component with soft properties. This opens up completely new and very individual application possibilities of 3D printing for plastic components," says Tobias Grün, product manager at voxeljet. TPU components produced with the HSS printing process have a particularly long-lasting permanent elasticity and excellent rebound properties compared to other TPU 3D printing processes. The successful cytotox test also confirms that there is no damage to cells and tissue when the material comes into contact with the skin. Furthermore, no discolouration of the components occurs. "With the HSS process, we can produce individualised polymer parts on-demand in high quality and at high 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 process offers enormous potential for future-oriented products," says Tobias Grün.
Partnership with material manufacturer Covestro
The TPU qualified for the HSS process was launched by voxeljet together with material manufacturer Covestro. "The close cooperation between the material and machine manufacturers enabled us to pool our joint know-how, coordinate and optimise the component quality and the 3D printing process," explains Tobias Grün. With this collaboration, the two companies aim to develop integrated material and process solutions for the economical additive large-scale production of polymer components.
voxeljet at formnext
From 15 to 18 November 2022, voxeljet will present its latest 3D printing solutions at formnext in Frankfurt a.M., the international trade fair for additive manufacturing technologies, at Stand E11 in Hall 12.1.
www.voxeljet.com
