Liners (also called chuck inserts) are typically made of urethane or rubber. They are inserted into a bottle capping chuck and the chuck is attached to a chuck capping machine such as our SA Benchtop Capping Machine or PS Capping Machine.
The liner grips the cap during the capping process. The grip generated by the liner is what allows the capping machine to tighten a cap onto a bottle.
Liners will last for a very long time but they do eventually wear out. So when you purchase a capping machine you should also purchase spare liners, but how many should you purchase? How long do liners last?
There is no simple answer to this question. We have customers that have capped over one million bottles with a single liner while other customers consume liners at a faster rate.
As a general rule of thumb, you should be able to tighten at least thousands of caps with a single liner and more than likely tens of thousands of caps with a single liner. For many of our customers that use their bottle capping machine daily, a dozen chuck inserts will last six months to a year.
For tips on how to extend the life of your liners, please click here