Profile: Propex Operating Company, LLC. is a supplier of fiber solutions for concrete reinforcement, with fiber concrete specialists and distributors. We also provide synthetic & steel fibers, and blended & synthetic fiber solutions. Our polypropylene fibers have the ability to mitigate the explosive tendency of concrete during fires, because they melt and relieve volatile steam pressure in concrete. We also offer Fibermesh® 650, and Fibermesh® 500 for the pre-cast market.