Is changing linen for Shabbos without washing permitted during the 9 days?
During the nine days, (for Ashkenazim, or the week of Tisha B’av for Sefardim) there are two parts to the prohibition regarding laundering clothing, 1. The actual washing of the clothes, and 2. Wearing freshly laundered clothing. Therefore even if the clothing was washed before the nine days we may not wear it. Included in this prohibition are freshly laundered lines and towels. However we may wear newly laundered clothing, or lines on Shabbos. Therefore you may change the linens for Shabbos.
Taanis 26b, 29b. O:CH 551-3, M:B 32.