The History of Clamshell Packaging

In 1978, the US inventor Thomas Jake Lunsford, took out a patent on his new package design, The Clamshell, a plastic blister package.

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

A hinged blister is known as a clamshell. The name of the clamshell is taken from the shell of a clam, resembling both form and function. Clamshells are useful for protecting products against external factors, such as humidity and contamination for extended periods of time. Clamshells are often made of a shaped plastic material such as:

Clamshell

• Polystyrene
• Polyester
• PVC
• Foam Sheets

The material can be made by thermoforming or by injecting mold into the desired shapes. A single piece of material is used for the top and bottom with a thin flexible hinge made from the same material as the two rigid pieces it connects rather than added separately.

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 heated sealed.

Clamshell packaging has been a popular choice among manufacturers for decades. Consumers can view the product while minimizing theft and damage. It is durable and can be used with interchangeable printed inserts so that one clamshell can often be used to package a number of products that are similar in size. Finally, empty clamshells nest well minimizing shipping costs and reducing the need for storage space. However, clamshells also created a substantial waste stream of hard plastics. In 2010, the packaging industry produced a more sustainable pasteboard blister packaging, while keeping the benefit of the clamshell design. The new design was made from recycled paper and plastic films. In addition to being better for the environment, the new designs provided a better base for advertising graphics. Folding cartons made of paperboard or molded pulp (packaging material, typically made from recycled paperboard and/or newsprint) can also be of a clamshell shape.

EPI’s Superior C-Wrap Labeling System provides clamshell labeling with ease. This system dispenses the label to the top, wrapping it around the front and applying it to the bottom. The label provides visual information as to if the package has been tampered with and remains closed until the consumer takes it home. Our C-Wrap System has taken a historically manually intensive process and made it simple and precise.