Capping Machinery - How Does a Spindle Capper Work?

Spindle cappers use sets of spinning disks to tighten threaded caps onto bottles and other containers as they pass through the capping area on a power conveyor. Automatic cap delivery systems present the cap to the bottle just before entering the tightening zone. The capping machine uses gripper belts on the side of the containers as well as a stabilizer bar to hold caps to allow for a consistent and reliable tightening of flat caps, sports caps, trigger sprayers and almost any other form of a continuous thread closure.

The obvious goal of any capping machine is to seal the product into the bottle or other container in order to protect the product from tampering, spilling or otherwise being damaged. Each piece of capping machinery manufactured by Liquid Packaging Solutions will use a different method to seal bottles based on the type of closure used for the packaging project at hand. Spindle cappers, which tighten a range of continuous thread caps, are one of the most produced capping machines at LPS. To better understand how the capping machine works, we can follow an imaginary bottle down a packaging line.

Typically, once a bottle receives product from an automatic filling machine, it will exit the fill area and continue down the power conveyor to the spindle capper. An automatic cap delivery system, such as a cap elevator or vibratory bowl, will orient caps and present them to a chute. The chute holds the caps just outside of the capping area to present to the bottles. As the bottles pass by the chute, a single cap is stripped for tightening. The stabilizer bar will normally present downward pressure on the closure to help protect against cross-threading or caps simply falling off of the container, though the stabilizer bar may take many different forms depending on the type of threaded closure being secured.

As the bottle and cap continue down the power conveyor and into the capping area, gripper belts will contact the bottle to keep it stable during the capping process. Depending on the size and shape of the container, some spindle capping machines may use a set of double gripper belts to ensure bottles don't tip, vibrate or otherwise move during the tightening process. With both the bottle and the cap now stabilized, the combination will proceed down the conveyor through the sets of tightening disks.

Normally three or four sets of spinning disks attached to spindles will be used to complete the capping process. These disks will essentially contact and thread the caps onto the bottle as they move through the capping machinery. Each set will normally be set slightly lower than the last, so that each pair the bottles pass will thread the cap slightly lower onto the bottle. The last set of disks will likely include a clutch to fine tune the tightening and avoid loose or overly tight seals.

Once the bottle and cap move past the last set of tightening disks, they will release from the stabilizer bar and gripper belts and simply continue down the power conveyor to the next piece of packaging equipment. The ability to continuously cap bottles, with only the need to replenish bulk caps when necessary, makes the spindle capper an ideal solution for threaded caps on an automatic packaging line.

To learn more about spindle capping machines, or any of the sealing equipment manufactured by LPS, click to reach the Capping and Sealing Page of the website.