Pads and belly bands can be washed on normal wash/dry settings using hot or cold water.  Do not use bleach or fabric softener.
Do not overload machine. Pads should have plenty of room to rinse thoroughly. 
18x24 size maximum load 8 pads
24x36 size maximum load 6 pads
30x36 szie maximum load 6 pads
34x36 size maximum load 4 pads
34x42 size maximum load 3 pads