Another powder-printing possibility: inkjet pure water onto hemihydrated calcium sulphate (i.e. plaster of paris - or maybe instead even Portland cement... possibly mixed with a fibre filler for strength). The CaSO4 solidifies in a few minutes.

Alternatively inkjet a solvent to fuse a powder; PVA and water might work quite well, or virtually any thermoset and a corresponding organic solvent for it. Thermosets dissolving in propanone (acetone) might be good, as propanone has a high vapour pressure and so would evaporate quickly and is not that toxic in a well-ventilated area (it's nail varnish remover).