MILLED FIBER is made from Advantex® glass. It has been engineered as reinforcement for foamed polyurethane, thermoplastics and thermosets and may be used under all normal conditions. It is glass filaments that are coated with a specific sizing to enhance resin compatibility. Unlike chopped strands, which are chopped to a precise strand length, milled fibers are milled to an average bulk density, which is determined by the input glass and process conditions.