Banner Hemming Question

We do the tape way of hemming. the way we do it works just fine and looks great. the only problem we get is bunching. When i finish hemming a banner i gently fold it over on itself (not making a crease or anyhting just a slight curl) and put it off to the side on another table. Later when i look at the banner, there is bunching where the curled part is. It's bunching up and my boss does not like it and neither do i. Is it because the glue hasn't settled long enough on the material? Should i not fold over the banner onto itself right away? what do you guys do? is it just something that happens and is a down part to using the tape system rather than sewing?

I appreciate your help everyone, I've been searching all afternoon and can't find the exact answer im looking for.
Thanks!

 

yeah our method is similar. i print a 1" tape section with a 1/16" gap from there to banner color. i flip the banner over and fold to the edge of banner color and crease sharply to make a nice fold. i then lay the tape down in that crease edge, peel off the backing, and fold the banner onto the tape, firmly and evenly applying from middle to outter edge, making sure of no air bubbles or creases or wrinkles. It turns out great! flat no wrinkles and the grommets go in perfect. but then putting off to the side to make room for the next it gets overlapped onto eachother, thus making a bunched up wrinkle of media. how can that be avoided? That previous post does not mention of what happens after you are done with the banner. Is this just what happens when using tape?

 

that could be the cause. i dont pull it super tight, but i make it taught, not bunched or loose or wavy. i'll try tapping in short intervalls and then go over with a squeegee. i was thinking that the glue was pulling itself in together, could be cause its too tight....hmmmm