How Does a Spindle Capper Work?

One of the most popular capping machines manufactured by Liquid Packaging Solutions is the Spindle Capping Machine. This bottle capper can be used for a wide range of products, providing that the containers are sealed with a screw-on type closure. While the most common screw-on type closure, also known as continuous thread caps, will be those found on the typical bottle of water or soft drink, there are many cap types that use a continuous thread. Some other examples of screw-on type caps include trigger sprayers found on popular cleaning products, pump caps found on liquid soaps and other products and flip top or sports caps found on different products.

So how does the spindle capper tighten all these different continuous thread caps? The machine uses a variety of features to stabilize both the cap and the bottle as it passes through sets of matched disks on spindles. As the bottle and cap pass by the matched sets of spindles, the spinning disks contact the cap to initiate the tightening.

Automatic spindle capping machines use a cap delivery system to allow for continuous capping of bottles. As caps move from an elevator or a vibratory bowl to a chute, they are placed correctly for introduction to the bottles. Caps that are not aligned correctly will fall back into the elevator hopper or bowl. This is the first step to ensuring reliable tightening. As the caps reach the end of the chute, they will be stabilized by a set of fingers that will hold the cap in the proper place for the bottle. As the bottle moves under the chute, it will strip a single cap from the chute, again ensuring that cap placement is correct for reliable tightening.

Once the cap in on the bottle, several different components begin to work in tandem to allow for consistent capping. A stabilizer bar will typically apply some downward pressure on the cap to protect against cross-threading. This bar may look different on different spindle cappers depending on the size, shape and type of closure being used to seal the bottles.

At the same time, as the container and bottle move through the capping area, gripper belts will be used to keep the bottle steady as it moves down the conveyors. For tall or oddly shaped bottles, a double gripper belt may be used to add more stability. The speed of the gripper belts will be matched to the speed of the conveyor to avoid tipping or jerking the bottles as they are being tightened.

Finally, the spinning disks found on the spindles will be adjusted to tighten the cap. Typically, three or four sets of spindles will be used, with each threading the cap a little bit further. The last set of spindles may include a clutch to fine tune the amount of torque applied as the caps are tightened. Sealed bottles then exit the capping area on the same conveyor, ready to be labeled, coded or otherwise prepared for the consumer.

Spindle cappers are also available as tabletop capping machines. These simple, semi-automatic machines will use a single set of disks to tighten caps. Tabletop machines may or may not add speed to a packagers process, but they will ensure that closures are consistent, avoiding over-tightening of caps as well as repetitive motion injuries for anyone who has been spending their day tightening caps onto bottles. With the tabletop capper, the operator simply places the cap on the bottle and slides the combination into the capping machine, where the spindle disks tighten the cap.

For more information, check out the Spindle Capping page of the Liquid Packaging Solutions website, or to find out if a spindle capper is the right machine for your own packaging project, call LPS to speak with a packaging professional today.