Do You Know Your Crimp Cappers?Do You Know Your Crimp Cappers?
Learn how different kinds of crimp cappers attach secure, permanent, and non-removable closures that protect products from leaks, evaporation, and contamination.
January 15, 2025

At a Glance
- Crimp capping is commonly used for perfumes/cosmetics, injectable pharmaceuticals, and aerosol cans.
- Learn the difference between three methods: segmented jaws, rotating chuck, and stationary rail.
Removable closures are not always desirable. Perfumes and other cosmetics, injectable pharmaceuticals, and aerosol cans are common examples of non-removable closures. Crimping is commonly used for permanent closure. Containers designed for crimp caps will have a ring at the top of the neck where the threads normally are. The cap, normally made of aluminum is normally crimped under this ring. Aerosol cans commonly use an internally crimped cap. Crimping may be done in several ways:
Segmented jaws: An advantage of this style is its simplicity. It can even be done manually. The crimping chuck consists of several jaws, typically 3 or more. The chuck is placed over the cap and an internal block holds the cap vertically. As the jaws are activated, they contract radially, bending the lower rim of the cap under the neck ring. Simultaneously, they pull the neck ring up against the vertical block. This compresses the rubber stopper, the gasket, or sealant in the cap assuring a leakproof seal.
Rotating chuck: Another common method is the use of a rotating chuck with a hold-down block and rotating wheels. As the chuck comes down (or the bottle comes up into the chuck) a pressure block forces the cap tightly against the bottle. Simultaneously, rotating wheels are cammed in. As they rotate around the cap, they fold the lower edge in. This type of crimper is available as a single-head intermittent machine. For higher speeds, continuous-motion rotary machines with multiple heads are available.
Stationary rail: Still another method uses a stationary rail. The bottle is indexed onto rotating pads on a rotary turret. A top bold down is lowered to compress the cap, center the bottle, and hold it in position. The bottle is rotated on its axis. As the turret rotates, it presses the edge of the rotating bottle against a curved fixed rail. The rail, combined with the rotations, folds the cap edge down crimping the cap in place:

Stationary Rail Crimper. (Changeover.com)
Aerosol and some other cans often use an internal crimp. After placement and gassing, the crimping jaws press the cap firmly onto the can, compressing the sealing gasket. The mandrel is pushed down, forcing the crimping jaws out, sealing internally under the neck:

Aerosol internal crimping jaws. (Changeover.com)
Find out more about crimping and other closing methods in John Henry’s Packaging Machinery Handbook, available at Amazon. Other chapters cover inspection, flexible packaging, coding, and all commonly used packaging machinery.
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