Choosing the Appropriate Capping Technology for Your Application
Capping machine design falls into two basic categories - In-line cappers and rotary Chuck-Style cappers. These machines differ dramatically in both their core design as well as in their techniques for applying closures.
Using In-line machines, bottles traveling on the infeed conveyor of the machine are gripped on their outer edges by side gripping belts that are speed matched to the conveyor. The neck of the gripped bottle passes under the cap dispenser and a cap is stripped-out directly by the finish of the neck. The closure resting on the finish passes through a series of cap tightening wheels that spin the cap onto the threaded neck finish. One final pair of wheels, which are equipped with friction clutches, delivers the desired torque to the capped bottle. The capped bottle is then released from the gripping belts at the discharge of the capper.
On Chuck-Style cappers, the oriented closure at the end of the cap chute is not picked-up by the bottle. It is instead picked out of the chute by a cap transfer device, which then places it into the gripping chuck of a capping head. This pick-and-place mechanism can be either a rotary starwheel with pockets or pegs or can be individual pegs associated with each capping head station. Bottles on the in-feed conveyor of the machine enter an in-feed timing screw that separates them to match the specific pitch of the capping heads. Bottles are transferred to an in-feed star wheel, which then delivers them to the turret star wheel where they are placed and centered directly underneath the capping heads. The rotating capping head with a cap held in its gripping chuck descends onto the bottle and applies the cap to the desired torque. Application torque is controlled by a clutch mechanism within each capping head. Once the cap is applied, the jaws of the chuck open and the head rises off of the capped bottle. Bottles are restrained from rotating while the cap is applied by a gripping system while the bottle is in the turret starwheel. Capped bottles are then placed onto the exit conveyor by a discharge starwheel.