We had the same problem with our magenta head and banner material in winter. The first foot or two looked good and then the magenta head would spew in everywhere. We didn't print a lot of banners, so we would put water in a spray bottle and spray the floor of the shop to raise the humidity before we would print a banner. The right way is to buy a humidifier. Nothing else works, I tried grounding the frame and a few other crazy ideas and nothing but raising the humidity worked.
On a side note, you might stop getting zapped by the laminator in winter too...