... printing 'in midair' is common with UV- and SLS-printers - then this 'midair' is viscouse polymer or not fused powder.
With UV-printers you have the cured polymer as material, with SLS you can use any powdered material you cna fuse with a smal hot spot (e.g. from a laser).
Most problems for SLS-printing is curling/warping of the parts when cooling down, so here a heated chamber around the printing area is needed ...
Viktor
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Call for the project "garbage-free seas" - [
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