When compounding polymers with a additives and fillers, unless effective venting is applied to remove moisture, the resulting pellets could contain volatiles causing surface defects in extruded or injection molded parts. Vent openings in the extruder barrel can be operated at atmospheric pressure or under vacuum, with most typical compounding processes including both. Quickdraft has developed a variety of vent-port designs to accommodate a wide range of applications and materials including vent stuffers, elongated vent barrels, and side vents, and machines can be equipped with multiple vacuum vents.