Fabric for air gravity conveyors. POLYAIR fabric is used by many of the major industry OEMs as original equipment. Our engineering has the expertise and experience in designing specific permeability values in fabrics to meet individual customer needs. The primary fiber is polyester and is available in interwoven and needled construction. POLYAIR polyester is heat treated at 350°F to insure maximum stability. Most popular widths are available woven to width or slit and heat sealed. Special wide one-piece constructions are available to 72" wider using longitudinal splice. Available in polyester and kevlar/polyester construction.