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

Blister pack

Blister pack is a term for several types of pre-formed plastic packaging used for small consumer goods, foods, and for pharmaceuticals.The primary component of a blister pack is a cavity or pocket made from a "formable" web, usually a thermoformed plastic. This usually has a backing of paperboard...

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Construction

Clamshell containers can be made of a variety of plastics such as polystyrene

Polystyrene

Polystyrene ) also known as Thermocole, abbreviated following ISO Standard PS, is an aromatic polymer made from the monomer styrene, a liquid hydrocarbon that is manufactured from petroleum by the chemical industry...

, polyester

Polyester

Polyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate...

, PVC

PVC

Polyvinyl chloride is a plastic.PVC may also refer to:*Param Vir Chakra, India's highest military honor*Peripheral venous catheter, a small, flexible tube placed into a peripheral vein in order to administer medication or fluids...

, foam sheets, etc. The material can by made by Thermoforming

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...

 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

Living hinge

A living hinge is a thin flexible hinge made from plastic that joins two rigid plastic parts together, allowing them to bend along the line of the hinge...

" that is integral with the material, rather than added separately.

Folding carton

Folding carton

The folding carton created the packaging industry as it is known today, beginning in the late 19th century. Basically, a folding carton is made of paperboard, and is cut, folded, laminated and printed for transport to manufacturers. The cartons are shipped flat to a manufacturer, which has its own...

s made of paperboard

Paperboard

Paperboard is a thick paper based material. While there is no rigid differentiation between paper and paperboard, paperboard is generally thicker than paper. According to ISO standards, paperboard is a paper with a basis weight above 224 g/m2, but there are exceptions. Paperboard can be single...

 or molded pulp

Molded pulp

Molded pulp, also named Moulded pulp or Molded Fibre, is a packaging material, typically made from recycled paperboard and/or newsprint. It is used for protective packaging or for food service trays and beverage carriers...

 can also be of a clamshell shape. It can also be made of cellulose fiber

Cellulose fiber

Cellulose fibers are fibres of cellulose from any source, either natural or manufactured.-Textile:In the textile industry regenerated cellulose is used as fibers such as rayon, . Cellulose fibers are manufactured from dissolving pulp...

 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

Adhesive

An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...

, pressure sensitive tape

Pressure sensitive tape

Pressure-sensitive tape, known also in various countries as PSA tape, adhesive tape, self-stick tape, sticky tape, or just tape, is an adhesive tape that will stick with application pressure, without the need for solvent, heat, or water for activation...

, label

Label

A label is a piece of paper, polymer, cloth, metal, or other material affixed to a container or article, on which is printed a legend, information concerning the product, addresses, etc. A label may also be printed directly on the container or article....

s, staples, or are heat sealed.

When plastic clamshell containers are securely heat sealed, they are tamper resistant and deter package pilferage

Package pilferage

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 shipping container...

. 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

Wrap rage

Wrap rage, also called package rage, is the common name for heightened levels of anger and frustration resulting from the inability to open hard-to-remove packaging, particularly some heat sealed plastic blister packs and clamshells...

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