The turning moment applied when tightening a screw closure onto a container.
Also called: on-torque; closing torque; cap application torque.
What does application torque describe?
Application torque is the turning moment applied while fitting and tightening a screw closure. Removal torque concerns opening; stripping torque concerns thread or cap failure. Report the unit, such as N·m or in·lbf, with the value; a force unit alone does not describe torque.
Name the bottle, closure and liner combination with the measurement. A capper setting, an observed tightening measurement and a later opening measurement are different records. The removal result should retain its own method and conditioning rather than being relabelled as direct application-torque evidence.
The correct range depends on the bottle finish, closure and liner. Too little tightening can leave inadequate contact; excessive tightening can damage the cap or threads. Diameter alone does not describe that combination.
Use an agreed range for the actual package and an appropriate measurement method in the trial requirement. Retain which capping head and operating condition produced each sample. A generic chart is not evidence that an offered package has been assessed at that value.
Does a torque result prove induction-seal integrity?
No. Torque describes closure tightening or opening, according to the measurement made. It is relevant to contact in an induction-sealing package, but the sealing result also depends on the material and process. Keep the torque evidence alongside, rather than in place of, the evidence for the required bond or leakage outcome.