I have a few cylinder screen printers and occasionally do HDPE squeezable water bottles, They do need to be primed (chemical wipe-on, flamed or corona discharge) I've been using a heavily retarded (butyl cellusolve) 2 part pad printing ink formulated for rubbers and flexible substrates and having moderate success, but I'm not really happy with the adhesion and durability.
Does anybody have any suggestions as to where to chase down the right ink? I suspect some of the bottle print big players are using UV cure inks as some of the printed bottles I've checked out have outstanding adhesion and chemical resistance, I'd be looking for air-cure.