On occasion, we have customer who wants a little advice on getting their classroom rug to lay flat. It may be because it had been stored all summer or maybe it's brand new and they are just unrolling it. Either way, there is a chance that the edges may curl up for a while. Here are some tips on how to get those pesky edges back in line:
Sometimes gravity and a bit of time are all a rug needs to lay flat. In other cases, you may need to reverse roll the rug, apply some heat or have the rug steamed to get rid of wrinkles. Wrinkles and creases are common in rugs that have been rolled or folded and then placed in storage, but you can encounter stubborn lumps in brand-new rugs as well.
Step 1
Give your rug some time. Spread the rug on the floor and let it sit for about two days to see if it relaxes on its own. If you can, place the rug on a hard floor rather than carpet while it relaxes, even if you plan to use it on carpet once it is wrinkle-free.
Step 2
Try back-rolling the carpet. To do so, unroll the carpet and then roll it again, this time rolling it in the opposite direction. Let the rolled carpet sit for a day or two and then unroll it again.
Step 3
Place a piece of furniture or a stack of heavy books on the creases for a few days to flatten them out using weight. If the corners of the rug are curling, curl them backward, flatten them back out and place weights in just the corners of the rug.
Step 4
If your rug still won't lie flat, apply some heat to it. Spread the rug over a clean concrete or asphalt slab such as your driveway on a sunny day. It's best to do this in the afternoon on a 75- to 80-degree F day, giving the surface time to absorb the sun's heat all morning. Usually, one or two hours in the sun is enough to release wrinkles and creases.
If you don't have a large enough patch of sun, flip the rug over and use a hair dryer to heat up the creases of the rug and release them. Always hold the hair dryer 6 to 9 inches away from the rug and use a sweeping motion. It's possible to melt rug fibers, so use a low or medium heat setting and keep the hair dryer moving back and forth at all times.
https://www.hunker.com/13413494/how-to-flatten-a-wrinkled-area-rug