In Mold Labeling

Hi People

Does anyone know a way of economically printing in mold labels digitally for the plastics industry?
We have sourced the PP material and conducted some trials and have found that good results are possible using our Mimaki UJF 3042 UV flatbed but the printing speeds and the ink cost are through the roof. I think some guys are using HP Indigo machines, is anyone willing to share their knowledge or experience?

Regards Neil