Up to now, air rings from Macro Engineering & Technology Inc., Mississauga, Ont., controlled blown film gauge by applying additional cooling air to selected segments of the ring’s circumference.
Up to now, air rings from Macro Engineering & Technology Inc., Mississauga, Ont., controlled blown film gauge by applying additional cooling air to selected segments of the ring’s circumference. Macro’s newest technology instead controls thickness by using valves to apply variable restriction to the air flow through individual segments rather than adding extra air. The new air-flow mechanism is now used on Macro’s D10 Pro air rings. It was shown for the first time last month at the Interplas show in Birmingham, U.K., and will appear for the first time in the U.S. at NPE next June in Chicago. Macro recently installed the first of this type on an 8-in.-diam. die for LLDPE. It replaced an air ring without auto gauge control and reportedly reduced the customer’s gauge variation from ±14% to ±3%.