Chemical Surface Treatment of Ultem 9085 Parts

The material Ultem 9085 is a flame-retardant thermoplastic polymer, which can be processed with Fused Deposition Modeling (FDM). Due to ist high strength-to-weight ratio and FST rating, Ultem 9085 parts are used in aviation. Process related staircase effects on rounded and slanting part areas require a surface treatment for end use parts. These processes include smoothing by mass finishing or coating in order to reduce surface roughness. An alternative smoothing technique is chemical surface treatment, such as the use of Acetone for ABS materials. In this paper, the surface of Ultem 9085 parts is treated with Chloroform vapor in order to solve material at the surface and smooth it. Therefore, specimens built in different build orientations are treated and tested with regard to surface roughness values and mechancial strength properties. The analysis of surface roughness and treatment time shows a significantly higher efficiency for chemical treatment in comparison to mass finishing. By employing chemical treatment, it is possible to reduce surface roughness by more than 80 % to Rz values of approximately 15 µm. Mechanical tests and measurements of the Melt Volume Rate (MVR) show no material destruction for chemical surface treatment at room temperature for less than 150 min.