Blown film producers continue to increase output rates with HMW-HDPE resins through the use of Internal Bubble Cooling (IBC) and air collars. It is believed the film's physical properties are affected by various pro cessing parameters such as output rates, neck height, BUR, and iris position. This study was undertaken to examine the relationship between these factors at various film thicknesses and to provide guidance for optimizing physical properties of the film using an IBC/air collar system.
