Air ring for blown-film extrusion apparatus

An air ring for use in a blown-film extrusion apparatus to form a polymer tube, the air ring comprising:

• a main body including a plenum through which pressurized air enters the air ring, the main body including a generally circular interior that is unobstructed vertically above the main body;
• a generally circular forming-cone assembly received in the generally circular interior of the main body, the forming-cone assembly including at least one annular passage extending through the forming-cone assembly from the plenum to an annular lip through which pressurized air from the plenum exits the forming-cone assembly for impingement upon the polymer tube, the forming-cone assembly being unobstructed vertically above the air ring, wherein the forming-cone assembly is removable from the main body by vertical lifting without removal of other components from the air ring.

An air ring for use in a blown-film extrusion apparatus to form a polymer tube, the air ring comprising:

• a main body including a plenum through which pressurized air enters the air ring, the main body including a generally circular interior;
• a generally circular forming-cone assembly received in the generally circular interior of the main body, the forming-cone assembly including at least one annular passage in fluid communication at one end with the plenum of the main body, and terminating in an annular lip through which air exits the forming-cone assembly and impinges on the polymer tube;
• an external flange on the forming-cone assembly that mates with a corresponding surface on the main body to support the forming-cone assembly within the interior of the main body, the external flange having an upper surface that is vertically unobstructed, wherein the forming-cone assembly is removable from the main body by vertical lifting without removal of other components from the air ring.