Clamshell (container)

Raspberries in a plastic clamshell package

Clamshell pack of screws

Foam clamshell for take-out food (here Thai fried rice with an Asian style spoon)

Newer paperboard clamshell for fast food

A clamshell is a one-piece container that folds onto itself to close. It is often made of a shaped plastic material similar to a blister pack.

Construction

Clamshell containers can be made of a variety of plastics such as polystyrene, polyester, PVC, foam sheets, etc. The material can by made by Thermoforming or can be injection molded into the desires shapes. A single piece of material is used for the top and bottom with a "living hinge" that is integral with the material, rather than added separately.

Folding cartons made of paperboard or molded pulp can also be of a clamshell shape. It can also be made of cellulose fiber such as sugarcane-bagasse,^[1] wheatstraw, wood pulp, etc.

Closing

Clamshells can use a variety of means of closing or sealing. Some have self-locking tabs, snaps, or have a friction fit. Others use adhesive, pressure sensitive tape, labels, staples, or are heat sealed.

When plastic clamshell containers are securely heat sealed, they are tamper resistant and deter package pilferage. These security packages are intentionally difficult to open, sometimes requiring customers to use scissors or a knife to open. This can be frustrating to the point of wrap rage.^[2]

See also

• Clamshell case
• Foam take-out container

References

1. ^ Sugarcane-bagasse clamshell box
2. ^ Clifford, Stephanie (June 2, 2011). "Clamshell packaging is being tossed". The Bulletin. New York Times News Service (Bend, OR). http://www.bendbulletin.com/article/20110602/NEWS0107/106020402/. Retrieved June 6, 2011. 

• Soroka, W, "Fundamentals of Packaging Technology", IoPP, 2002, ISBN 1-930268-25-4
• Yam, K. L., "Encyclopedia of Packaging Technology", John Wiley & Sons, 2009, ISBN 978-0-470-08704-6