I washed my quilt, a Mysa Gräs from IKEA, a very synthetic thing that crackles with electricity when pulled out of the cover. Wash at 60°, tumble dry. When I took it out of the dryer it felt strange to the touch—the polypropene surface had partially melted. A complete write-off.
Apparently immersion in liquid at 60° is not the same as being blown through by air at 60°.