Bottle capping chuck inserts (also called liners) are wearable items that periodically need to be replaced. You can extend the life of your liners by making sure that you set the torque output of your capping machine correctly. In almost all cases, excessive chuck insert wear occurs when the capping machine is applying too much torque to the cap.
We have all experienced tightening a cap by hand. When tightening a cap by hand, we can tighten it to a certain point until we cannot tighten it any further. Basically, the cap can only accept a certain amount of torque.
This same principle occurs when tightening a cap with a bottle capping machine. The cap can only accept a certain amount of torque. If the capping machine is set to provide more torque than the cap can accept, then the cap will stop rotating before the capping machine stops trying to tighten it. Since the cap stops first, the capping machine is spinning the liner on a cap that is no longer rotating. This quickly wears down the liner.
To eliminate this problem you need to reduce the torque output of the capping machine. Ideally, you want to calibrate the capping machine so it is applying only that amount of torque that the cap can accept and no more. You want the capping machine to stop applying torque at the same time that the cap is completely tightened. When the chuck insert and cap stop simultaneously, liner wear is eliminated.
If you are considering the purchase of a capping machine it is very important to make sure that the output torque range of the capping machine that you purchase is well matched with the torque requirements of your caps. Be sure not to purchase a capping machine with an output torque range too high for your caps as liner wear will always result.
When using a Kinex Capping Machine it is easy to tell when you are applying too much torque to the cap and when you are not. The clutches in our capping machines are designed to automatically shut off the capping machine when the selected amount of torque has been applied to the cap. If the torque output is set to a level that the cap can accept, the capping machine will automatically shut off the instant the cap is tight and no liner wear will result. If, on the other hand, the torque output is set higher than the cap can accept, the capping machine will not shut off, the capping machine will spin the liner on the cap that is no longer rotating and excessive liner wear will result.
So, in summary, when tightening your caps make sure you are not applying more torque to your caps than they are capable of accepting. Lower the torque output of your capping machine. If you find that you lowered the torque output of the capping machine too much and your caps are not as tight as you would like them to be then increase the torque output, but only very slightly. Make very slight increases to the torque output until you find the level of tightness that you desire.