The BMW i Ventures fund invests in Rapid Liquid Print and gel 3D printing of very soft elastomers

The investment fund of the world’s leading car manufacturer – BMW i Ventures, provided financing for the Rapid Liquid Print (RLP) start-up, developing innovative gel 3D printing technology from very soft and flexible materials such as foam, rubber and silicone. The process consists in extruding materials in a gel environment, creating any spatial structures out of them, which do not require the use of support structures. According to BMW, RLP technology eliminates the geometric limitations of traditional layer-by-layer 3D printing of elastomers, offering high-quality, low-cost and large-scale production of applications for the medical, clothing and automotive industries.

3D printing from elastomers has always been associated with a number of difficult challenges. When it comes to the FDM / FFF technology, the material in the form of a line cannot be too flexible because it starts to curl and block in extruders (the real lower limit is 70-75A on the Shore scale, where most popular 3D printers start to have problems already below 85A). Additionally, to be able to achieve lower levels of flexibility, the 3D printing process itself must be excruciatingly slow, because as the speed increases, the risk of extruder blockage increases …

In powder technologies such as SLS or MJF, flexible materials in the form of TPU appeared relatively recently and their share in the total production using this method is still small. Here, too, we will be limited in flexibility, because the production process is a very finely-ground material, of which some flexibility simply cannot be achieved by selective laser sintering.

As for resin technologies, they are a viable alternative to achieving the expected flexibility, even at 50A on the Shore scale, but nevertheless:

• in the SLA technology, it will be necessary to use support structures, after their removal, the models will have permanent and not very aesthetic traces
• PolyJet technology is the most perfect for this type of application, but unfortunately it compensates for it with the price – 3D prints from flexible materials with dimensions larger than 100 mm in XYZ axes are much more expensive than the average photopolymer 3D printer printing in UV LCD technology …
• in both cases, applications at the level of 300 mm on the XYZ axes become very expensive and problematic in terms of the technology itself
• Finally, it should be remembered that we are dealing with resins which imitate the properties of specific elastomers, but are not; in other words, you cannot print here, for example, from silicone, but from a resin that resembles it.

The gel dispensing technology developed by RLP works completely different. The method was first introduced at Design Miami in 2017. It is a 3D printing process in which a fluid material can be extruded into a gel slurry. Printouts are hardened during production, do not require supports and significant post-processing. At the same time, the scalability is much simpler than with other additive techniques and enables the production of large-format parts with extremely high throughput.

According to RLP, this approach is better than conventional elastomeric 3D printing technologies because it is not limited by speed, construction volume or material shortages. According to the company, there are many industries that qualify for this technology. This includes the fields of medicine, footwear, aviation, and the automotive industry.

RLP is managed by an extremely experienced team with experience in running additive manufacturing projects and developing innovative machines and production systems. Schendy Kernizan (founder and CEO) co-led and managed researchers and students at the MIT Self-Assembly Lab with projects for companies such as Google, BMW and Steelcase. Bjørn Sparrman (co-founder and CTO) managed the technical operations at the MIT Self-Assembly Lab and led the development of the RLP 3D printing technology from its inception. The team also includes Skylar Tibbits – one of the precursors to the idea of 4D printing.

Source: www.bmwiventures.com
Cover photo: www.youtube.com