Choice of hardness with 3D printing

With Selective Laser Sintering, it is possible to use flexible materials like TPUs. By modifying the manufacturing parameters, Sirris can modify their hardness to produce parts with different characteristics or to vary the properties within the same part. 

SLS (Selective Laser Sintering) often uses PA12 powders. For some time now other materials have appeared on the market, which make it possible to diversify the properties of prototypes or manufactured parts and to anticipate new applications.

Sirris had already acquired experience with the use of polypropylene on its SLS - Prodways machine (acquired with the funds of the IAWATHA ERDF project); now it is studying the 3D printing of structures in TPU elastomer.

Together with a student engineer from Helmo-Gramme (F. Greffe) who is producing his dissertation at Sirris, work has been carried out on how to vary the mechanical properties of TPU simply by acting on the printing parameters. From the material TPU-70A, it was possible to obtain Shore A hardnesses of 70, 75, 80 and 85.

It is now possible to produce different prototypes with different properties without changing materials and also to obtain different hardnesses within the same part.

TPU is used in a wide range of applications including bellows, seals, hoses, toys, and soles. Its high elongation capacity enables the printing of flexible objects with a high level of precision and resolution.