The saturated felt then passes through drying-in drums and onto the wet looper,
sometimes called the hot looper. The drying-in drums press surface saturant into the felt.
Depending on the required final product, additional saturant may also be added at this point. The
amount of absorption depends on the viscosity of the asphalt and the length of time the asphalt
remains fluid. The wet looper increases absorption by providing time for the saturant asphalt to
penetrate the felt. The wet looper operation has been shown to be a source of organic particulate
emissions within the asphalt roofing process; however, the portion that is POM has not been
defined (U.S. EPA, 1980; Kelly, 1983).