New Aluminum Lug Closure Reduces Removal Torque while Ensuring Hermetic Seals in Glass Jars

The development and introduction of a vacuum release aluminum (VRA) lug closure into the glass jar market constitutes an important innovation in the food packaging industry by significantly reducing the torque needed to remove the lid from the glass jar, thus facilitating jar opening by consumers. The new lids were compared with the industry standard, steel lug closures, for sealing performance and torque removal. Closure of glass jars hot-packed with deionized water was evaluated by measuring pull-up, vacuum, security, and removal torque. The effects of hot-pack temperature from 82 to 93°C and headspace at 6 and 10% on the integrity and opening of glass closures were studied. Jars packed with tomato sauce and capped with both types of lids were evaluated for ease of opening by measuring removal torque. Performance of the new VRA lug lids was similar to that of the standard lids for all parameters measured except removal torque. Removal torque values for jars sealed with VRA lids were 20 to 51% lower than those for the standard lids.