The bottle, closure and capper must be considered together.
A bottle cap feeder is part of a complete capping process. The cap must arrive correctly, the bottle must be stable, and the capper must apply the closure without cross-threading, tilting or missing caps.
Feeder design changes depending on bottle size, conveyor speed, cap type, capping head and available space. Tall, unstable or lightweight bottles may need extra handling at the capper, even if the cap feed itself is reliable.
This route is useful when the project is not just a feeder purchase, but a line improvement or retrofit around an existing bottle capping machine.