
A clamshell is a one-piece container consisting of two halves joined by a hinge area which allows the structure to come together to close. Clamshells can be made to be reusable and reclosable or can be sealed securely.
Construction
Clamshell containers can be made of a variety of materials. Plastics such as
polystyrene
Polystyrene (PS) is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is ...
,
polyester,
PVC, foam sheets, etc. The material can be made by
thermoforming
Thermoforming is a manufacturing process where a plastic sheet is heated to a pliable forming temperature, formed to a specific shape in a mold, and trimmed to create a usable product. The sheet, or "film" when referring to thinner gauges and cert ...
or can be
injection molded into the desired shapes. A single piece of material is used for the top and bottom with a "
living hinge
A living hinge or integral hinge is a thin flexible hinge ( flexure bearing) made from the same material as the two rigid pieces it connects. It is typically thinned or cut to allow the rigid pieces to bend along the line of the hinge. The m ...
" that is integral to the material, rather than added separately. Clamshell packaging works great for packages that need to hold heavy products, or items like electronics that are a target for theft.
Folding carton
The folding carton created the packaging industry as it is known today, beginning in the late 19th century. The process involves folding carton made of paperboard that is printed, laminated, cut, then folded and glued. The cartons are shipped f ...
s made of
paperboard
Paperboard is a thick paper-based material. While there is no rigid differentiation between paper and paperboard, paperboard is generally thicker (usually over 0.30 mm, 0.012 in, or 12 points) than paper and has certain superior attribute ...
or
molded pulp
Molded pulp or molded fiber (also spelled as moulded pulp or moulded fibre) is a packaging material, that is typically made from recycled paperboard and/or newsprint. It is used for protective packaging or for food service trays and beverage ...
can also be of a clamshell shape. It can also be made of
cellulose fiber
Cellulose fibers () are fibers made with ethers or esters of cellulose, which can be obtained from the bark, wood or leaves of plants, or from other plant-based material. In addition to cellulose, the fibers may also contain hemicellulose an ...
such as sugarcane-bagasse, 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
Pressure-sensitive tape, known also in various countries as PSA tape, adhesive tape, self-stick tape, sticky tape, Sellotape, or just tape, is an adhesive tape that will stick with application of pressure, without the need for a solvent (such a ...
,
label
A label (as distinct from signage) is a piece of paper, plastic film, cloth, metal, or other material affixed to a container or product, on which is written or printed information or symbols about the product or item. Information printed d ...
s, staples, or are heat-sealed.
Opening
Many clamshell containers are easy to open, and reuse, by consumers. When plastic clamshell containers are securely heat sealed, they are
tamper resistant
Tamperproofing, conceptually, is a methodology used to hinder, deter or detect unauthorised access to a device or circumvention of a security system. Since any device or system can be foiled by a person with sufficient knowledge, equipment, and ti ...
and deter
package pilferage
Package pilferage is the theft of part of the contents of a package. It may also include theft of the contents but leaving the package, perhaps resealed with bogus contents. Small packages can be pilfered from a larger package such as a shippin ...
.
These security packages are intentionally difficult to open, sometimes requiring customers to use scissors or a knife to open.
Scissors
Scissors are hand-operated shearing tools. A pair of scissors consists of a pair of metal blades pivoted so that the sharpened edges slide against each other when the handles (bows) opposite to the pivot are closed. Scissors are used for cutt ...
have been demonstrated as effective at opening packaging of this type.
Difficulty opening such packaging can be frustrating to the point of
wrap rage. Some people injure themselves trying to open security packaging which in the United Kingdom has been cited as the most frustrating to open.
See also
*
Foam food container
A foam food container is a form of disposable food packaging for various foods and beverages, such as processed instant noodles, raw meat from supermarkets, ice cream from ice cream parlors, cooked food from delicatessens or food stalls, or bever ...
*
Solander box
A Solander box ("S" may also be in lowercase), or clamshell case (mainly in American English), is a book-form case used for storing manuscripts, maps, prints, documents, old and precious books, etc. It is commonly used in archives, print rooms and ...
*
Living hinge
A living hinge or integral hinge is a thin flexible hinge ( flexure bearing) made from the same material as the two rigid pieces it connects. It is typically thinned or cut to allow the rigid pieces to bend along the line of the hinge. The m ...
Notes
References
* Soroka, W, "Fundamentals of Packaging Technology", IoPP, 2002,
* Yam, K. L., "Encyclopedia of Packaging Technology", John Wiley & Sons, 2009,
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Containers
Food storage containers