Learn about Flexible and elastic 3D-printing resins

Whilst the 3D-printing market grows rapidly, the demand for better 3D-printing materials grows with it. This leads to the development of a wide variety of materials. All new types of resins are finding their way into the market for specific applications. Earlier we wrote an article about the Strongest and Toughest materials available. One of which are the flexible 3D-printing resins often referred to as elastomer or rubber/ rubber-like materials.

Source picture; Carbon3D and Footwear News with their elastic 3D-printing resin

These flexible and elastic 3D-printing resins open up a whole new field of applications and have a very positive effect on the growth of the photopolymer market. But how are these materials defined and how do they compare with competitor flexible and elastic resin? When looking for a resin for a specific application these are important questions to ask and therefore the main target for this article is to compare different flexible resins which are available in the market anno December 2020.

It is important to notice that the overview shows a comparison between the materials and is not a list of which materials is the best. In addition, note that in the comparison only resin is viewed of which a complete datasheet was available. All data used is based on data published by the suppliers.

Flexible and elastic resin is commonly defined by different properties then other 3D-printing materials because of the difference in mechanical behaviour. The hardness is expressed in Shore A instead of shore D, which is commonly used for hard resin. A higher number in Shore A hardness, would mean a harder material. Toughness is often expressed in Tear strength, whereas for hard and tough materials an impact strength would be used to express toughness.

How to select the best flexible / elastic resin for your project?

There are a couple things that are important when selecting the best flexible resin for your project. First of all the complete set of mechanical data would need to be evaluated before choosing the right material for your application. For most real-life applications it is worth to focus on materials with a decent tear strength. Materials with a tear strength <10 kN/m would be only suitable for prototyping applications, whilst for high demanding applications like midsoles, you would want a tear strength as high as possible. The elongation and Shore A tells something about the actual flexible behaviour of the material. A high elongation and low Shore A, would indicate that the printed parts actually feel soft and flexible. We noticed that some companies (often cheap resins and not listed above) offer flexible resins which are actually rigid/tough instead of flexible. Next to the mechanical properties it is also important to think about 3D-printer compatibility and post-processing.

Printing with flexible and elastic resins will require a bit more skills compared to rigid resins. More information about settings for your printer or tips and tricks for supporting can be found at the links.

Printer compatibility of flexible 3D-printing resins

Printer compatibility is an important parameter when selecting your flexible or elastic resin. Companies like Carbon and Formlabs are developing processes and materials at the same time, making the materials slightly better, but also nearly un-processable on any other platforms / 3d-printers. With Flexible-X we balanced the material properties and processability, making an overall good material that can be printed on most open DLP, SLA, LCD / MSLA platform with the right wavelength and power.

In which application could you use a flexible material?

The most well-known application for flexible / elastic 3D-printing resins must be the lattice structure midsole that Carbon3D and Adidas launched. Thinking about this technology were flexible and elastic resins are used in a lattice structure, one could replace a lot of custom foam applications.

Source: Carbon3D and Adidas

Foams are used in a lot of applications, thinking about car seats, headrests, shoes, saddles, helmet liners and many other applications.

Other applications are in the field of wearable devices like the smart watch strap printed by a partner on the Atum3D printer, as shown in the picture below.

Note: printed objects that come in contact with food, skin or any other living organism need to be certified in a certain Class to ensure the object does not harm   

In the field of personal protective sensors, wearable link is utilizing 3D-printing technology to protect people, equipment and areas.

Source: PLINX Wearable link

Other applications in the field of prototyping, earbuds, seals and soft touch applications could be interesting in combination with Flexble 3D-printing resin. Send us a message at info@liqcreate.com, on Facebook or Instagram to show what you have been printing in our flexible resins!