Operates machine to extrude thermoplastic materials and manufacture blown (packaging) film according to specifications: Operates machine and may adjust controls to regulate vacuum, air pressure, sizing rings, and temperature; and synchronizes speed of extrusion with pulling rolls. Measures extruded articles for conformance to specifications, using micrometers, calipers, and gauges; and adjusts speed and weight controls or turns water, air, or valves to obtain product of specified dimensions.