Microfiber cloth can be fickle. It will last for 500 launders, but you have to treat it differently than cotton products. With cotton, more harsh chemicals and hotter temperatures are needed to sterilize your cleaning products due to cotton's organic "petri dish" tendencies to harbor bacteria.
As a petroleum-based product microfiber will is naturally resistant to such behavior. However, the delicate construction of the 1000's of tiny hooks and crannies, that result from splitting microfiber during construction, easily clog and will melt when heated, on a microscopic level.
While the visible appearance may not change, you will notice a distinct lack of 'grabbing' in the hand feel if you are not careful. Fewer chemicals, low heat, and air drying are the key takeaways of our Caring For Microfiber guide. Follow the link to microfiber care instructions, and a downloadable PDF for your facility.