If actually ESD is your problem (which I don't think), then the use of an industrial ionizer is a good remedy. It's widely used in the plastics industry.
Of course, avoiding of highly isolating rollers is essential, but even without any additional isolators only the isolation of wires is enough to produce ESD. And this could be well removed by the help of an ionizer.

I don't think, that ESD is the major cause of your problems, because you told that the whole machine is made of metal and everything is grounded. And: Because the isolation of wires is removed rather slowly, there should be enough time for the electrostatical charge to flow and to relax the electrostatic potential. Ok, I should have a detailed look at your actual application to be more concrete.

Good luck,
Kai