Crystallization of polyamide-11 in Selective Laser Sintering Conditions

Polyamide-11 (PA11) powders are very suitable for several Powder Bed Fusion technologies such as Selective Laser Sintering (SLS) [1]. SLS is an additive manufacturing technology consisting in spreading a thin layer of powder then exposing the desired areas to a laser radiation to selectively melt the powder and finally iterating these two steps [1]. SLS process temperatures lead to quasi-isothermal crystallization conditions of semi-crystalline polymers. As the mechanical properties and dimensional accuracy of the printed parts highly depend on their crystallinity, such conditions have widely been investigated for polyamide 12 [2,3] which is the most used polymer in SLS but much less for PA11.

Crystallization kinetics of PA11 in the range of SLS process temperatures has been investigated by Differential Scanning Calorimetry (DSC) and Polarized Optical Microscopy (POM) as well as its rheological behaviour. These data will help designing new PA11 based materials for SLS and feed numerical models to simulate the behaviour of the materials during the SLS process.

References:
1. Wang, Y.; Xu, Z.; Wu, D.; Bai, J. Current Status and Prospects of Polymer Powder 3D Printing Technologies. Materials, 2012, 13 (10), 2406
2. Balemans, C.; Loojimans S. F.S.P.; Grosso, G.; Hulsen, M. A.; Anderson P. D. Numerical analysis of the crystallization kinetics in SLS. Additive Manufacturing, 2020, 33, 101126
3. Drummer, D.; Greiner, S.; Zhao M.; Wudy, K. A novel approach for understanding laser sintering of polymers. Additive Manufacturing, 2019, 27, 379-399