Proper torque is required for the cap to perform its functions of maintaining a tight seal.
[1] It is a piece of specific quality control equipment that can be placed on the production line or in the laboratory.
[5] It can be used as a destructive tester to identify if there is any material weakness of the packaging during the screwing process.
The lower torque limit is considered the minimum pressure of the cap to avoid any leak of the product.
Temperature variations can modify product characteristics with a result of different torque measurement.