Red phosphorus and ATH proved provided fire performance compatible with ABS 3D-Printing. A total load of c. 21% of the PIN FR combination microencapsulated red phosphorus and ATH (aluminium trihydroxide), 2:1 ratio redP:ATP, was compounded into ABS at 185°C – 215°C, then dried, then extruded at 190°C – 225°C to a standard spline. This was then printed on a Tiertime UP-BOX+ MEM (Melted Extrusion Modeling) printer. Fire performance was tested on the spline (solid plastic) not after 3D printing. LOI was increased from 24.5 (neat ABS) to nearly 30, achieving UL 94 V0 (3 mm). Mechanical properties of the ABS deteriorate with addition of the PIN FR (c. 1/3 loss in tensile strength and elongation at break), but the material remains compatible with 3D-printing on the Tiertime machine, printing smoothly, without clogging or warpage, resulting in a high-quality surface finish.
“Study on Additive Manufacturing of ABS Flame Retardant Wire”, Y. Zhong et al., Journal of Physics: Conference Series 2021 (2021) 012012 https://doi.org/10.1088/1742-6596/2021/1/012012