disclosed herein are a method and apparatus for combining two or more streams of a polymeric material to form a plastic object . the method and apparatus are capable of ending an interior layer of the plastic object at a desired length to avoid the need to clean selected surfaces of components used to form the plastic object . the method and apparatus increase the velocity of the polymeric material used to form the plastic object in certain components used to form the plastic object . the increase in the velocity of the polymeric material facilitates the ending of the interior layer of the plastic object .