As part of the strategic growth of their additive manufacturing business unit, rpm rapid product manufacturing has added DLP (Digital Light Projection) in large format using the EnvisionTec Xtreme 8K and the Adaptive3D material ETR 90 (Elastic ToughRubber™). ETR 90 is part of a growing set of additive materials that are designed for long term performance in industrial applications. The addition of a Shore 90A material allows rpm to strategically target additional series applications on a high throughput machine. rpm is working with their customers on both “design for additive applications” and providing the option to complete polyurethan casting projects into faster and lower-volume ETR 90 production opportunities.
Series Additive Manufacturing with Elastic Materials using DLP
The last 5 years have brough significant advances in additive materials opening the doors to series applications. The most recent addition is ETR 90 from the team at Adaptive3D who brought together smart material science and a focus on industrial applications to develop, another series AM material. The material is unique in being both tough and resilient like a standard rubber material. This a strong match for many existing mechanical profiles in mobility, automotive, oil & gas and the industrial goods space. ETR 90 also has a wider temperature range than most polyurethane materials due to a different chemical base, which also helps to cover different application profiles than existing materials.
When rpm started operations 25 years ago, the only option to move into series applications was by adding capacity for NylonMold (PA 6 casting), polyurethane casting and reaction injection moulding. Because rpm focuses on series applications alongside their functional prototyping and P-Series applications, their technical director Dr. Jörg Gerken is constantly on the lookout for materials that can augment their existing portfolio of 12 in-house technologies. While evaluating ETR 90, rpm performed a series of benchmark projects with existing customers for typical applications including cases, gaskets, sealing elements, compression pads, cable covers and bellows. Because the Adaptive3D ETR 90 material is developed for a top-down DLP process, the parts are supported by the resin during printing which helps to reduce the amount of support required and enables geometries that are not possible using other systems.
ETR 90 successfully passed the benchmark tests in terms of geometry, surface quality and mechanical performance by both rpm and their reference customers. That opened the doors to adding a second Shore 90A elastic material into the rpm production portfolio.
As technical director for a both prototype and series-focused manufacturing provider, I am always looking for materials that not only offer improved material properties, but which also withstand the long-term functional demands of real-world applications. ETR 90 fulfils these demands with best-in-class combination of toughness, tensile strength and modulus of elasticity for 3D printed elastomers in Shore 90A. This is particularly important for applications where traditional elastomers would usually be replaced by our polyurethane casting materials, since we have an additional benefit of not requiring a mould to begin production.Dr. Jörg Gerken, Technical Director
rpm – rapid product manufacturing GmbH
High-Throughput 3D Printing as an Alternative to Polyurethane Casting or Injection Moulding
A typical use case for ETR 90 (Elastic ToughRubber) will be shifting existing polyurethane casting projects at rpm into additive manufacturing. Based on over 20 years of experience casting technical parts in silicone forms, it is clear this technology can be an interesting alternative from both the technological and economic perspective. Especially interesting are larger parts at lower order quantities, where the mould cost has an outsized effect on part price.
For smaller elastic parts, the key advantage will be a faster turn-around time. The large build plate allows for batches of 20 – 200 parts within a single iteration, multiple times per day. These types of parts can begin to substitute injection moulding parts, similar to the developments we have seen with SLS parts. For larger parts like flexible covers, connection joints, cable holders or fluid systems, rpm will use ETR 90 to send the first parts within a few days. Then the full batch can be delivered in injection moulding or small series casting.
European Production Centre for ETR 90 (Elastic ToughRubber) and the EnvisionTec Xtreme 8K
rapid product manufacturing GmbH is officially the first European production centre available to the public for this unique material. Alongside existing customer projects, they will begin printing benchmark parts for Adaptive3D (Desktop Metal) to shorten lead-times from the USA and focus on validating series applications. Since rpm has been working with DLP technology, elastic materials and lattice applications for more than four years, they could bring the machine into production and begin optimizing parts in just a few weeks.
New customers will be able to experience the material properties of ETR 90 and benefit from the additional rpm capabilities including data security via TISAX approval, assembly or post-production in-house, two shift production, ISO 9001:2015 validation and a GOM ScanCobot with ATOS Q for automated quality assurance of elastic parts in series. Adding this series technology to rpm is also timely as the worldwide focus on glocalization and adding multiple layers of backups for supply chains picks up steam. The combination of ETR 90 material and a large-format, production-ready AM machine brings access to rapid manufacturing from a single, competent hand.
We see that a low-cost replacement for technical rubber can open up the possibilities for additive manufacturing of small batches and spare parts, especially for industrial goods and automotive applications. ETR 90 will be an important addition to for our material portfolio. It provides a solution for low-volume PU moulding, fast-turnaround injection moulding and flexible 3D printed parts with higher demands on mechanical performance than we achieve in other technologies. As the first European production location for ETR 90 we are continuing the tradition of rpm to spot key technical materials and establish ourselves as a leading solutions provider in series production applications.Dr. Claus Thomy, Managing Director, Sales
rpm – rapid product manufacturing GmbH
More information about the material on the dedicated DLP technology page.