| abstract |
The present invention relates to systems and methods for solid freeform fabrication, especially selective laser sintering, as well as various articles made using the same, where the systems and methods utilize certain thermoplastic polyurethanes which are particularly suited for such processing. The useful thermoplastic polyurethanes are derived from (a) a polyisocyanate component, (b) a polyol component, and (c) an optional chain extender component; wherein the resulting thermoplastic polyurethane has a melting enthalpy of at least 5.5 J/g, a Tc (crystallization temperature) of more than 70C, a ?(Tm:Tc) of from 20 to 75 degrees, where ?(Tm:Tc) is the difference between the Tm (melting temperature) and Tc. |