You can pad a plastic drainpipe and wrap it in acid-free tissue, then carefully roll the banner round the pipe. Make sure the banner is interleaved with acid-free tissue throughout. Make a simple cover from Tyvek fabric or plain unbleached cotton, gently tied on with wide cotton tapes. Suspend the pipe by S-hooks in chains from the ceiling. That way the banner is not crushed under its own weight. Remember to take a picture of the banner and include it with the label tied to the outside of the cover.
Hope this helps