Cotton and polyester are both commonly used fabrics in clothing. While cotton tends to wrinkle more easily, polyester does not. Also, while cotton is a natural fiber, polyester is synthetic. Underwear made from a blend of 65 percent polyester and 35 percent cotton will stay in good shape and last for a long time if washed properly. Failure to use the right temperatures and laundering methods may result in fabric damage or shrinkage.
Set the washing machine to the warm temperature setting. Choose permanent press or normal for the wash cycle.
Let the washer fill up with water. Add the recommended amount of laundry detergent per the label instructions as the washer is filling up. If the underwear are white, you may add the recommended amount of chlorine bleach as well.
Place the cotton and polyester blended underwear into the washer. Add other items of like color and that can be washed in warm water if you would like. Avoid overfilling the washer, however, as the underwear and other garments need room to move around freely.
Let the washer run through a complete wash, rinse and spin cycle. Take the underwear out of the washer and place them in the dryer.
Turn the dryer to low or warm heat and allow the underwear to dry completely. Take them out of the dryer as soon as the cycle is finished.