APPARATUS FOR DISPENSING A COMPOSITION

Provided are an apparatus and methods for dispensing a composition, the apparatus includes a barrel (120) having an inlet (128) and an outlet (129), a screw (122) received in the barrel, and a drive mechanism operatively coupled to a shank end (134) of the screw to rotate the screw. The screw is hollow and includes both interior and exterior surfaces, the interior surfaces defining a cavity (142) adjacent to the outlet, and wherein the screw further includes a plurality of apertures (140) through which the cavity and exterior surfaces communicate with each other. The apertures are located along a perforated portion (146) of the cavity, where the perforated portion can have a transverse dimension that increases with distance from the shank end. The apertures can also provide a hole area, relative to the exterior surface of the screw, that increases with distance from the shank end. The screw can also include a helical flight (132) having a raised flight section (150) and one or more lowered flight sections (152), where the apertures are at least partially located on the lowered flight section.