If it has Kevlar, you might tumble dry it with no heat (and wash on warm or cooler), but it is probably best not to dry Kevlar with heat. Heat, especially dry heat, will break down the molecules and therefore weaken the Kevlar's ability to resist abrasion.
Disclaimer: I don't have riding jeans (I have leathers for moderate temps and a full Kevlar suit for temp extremes). My leather jacket has armor, but not my chaps. If I ever get another pair of chaps, they will accommodate knee armor, at the least, and I hope I can find some that I can find some that accommodate some hip armor.
I've been down pretty hard twice. No hip armor (and having my wallet in my pocket - first lesson learned that day) left a NASTY bruise on my hip the first time. Riding 675 miles home the next day was really tough because of that bruise! There was no armor in the hips of the textile pants I was wearing that day (second lesson learned that day). With the armored Kevlar suit, I walked away from the 2nd accident without a scratch or bruise even though I ended up in a gully, between the bike and a rock wall that I hit hard. My bike was totaled and my full face helmet was shattered. I was run off the road by a car coming the other way on the Tail of the Dragon that time. Point is, Kevlar or leather, and armor may very well prevent serious injury if you are ever in an accident.