Blister Packaging. Have you noticed all the products that come in plastic, aluminum or cardboard-backed and plastic-faced pockets? These packages are commonly called blister packs. Blister packaging is widely used in retail and medical fields.
One of the most common uses of blister packaging is in over the counter cold and flu medications. These medications often come in packages containing cards known as blister cards. These cards are typically made of aluminum foil, cardboard, or plastic pockets. These pockets contain a single (or unit) dose of medication. Getting a unit dose of medication is simply a matter of opening the blister pocket on the card. Attempting to find the dosage information on the back of the box is eliminated; guesswork is eliminated, and dosing is easier and more accurate.
Blister packaging consists of "blister packs" or "blister cards." These cards hold pre-formed pockets made from a formable web, usually of thermoformed plastic, such as PVC. The card that holds these blisters is usually made of paperboard, aluminum foil or plastic. The empty blister on the card is filled and then sealed, usually also with paperboard, aluminum foil or plastic. When the blisters are formed, filled and sealed in one process on the same machine, it's referred to as a "form fill seal" process.
Blister packaging uses pockets created from either thermoformed plastic or cold form foil. If the plastic is thermoformed, it has been unwound from a spool and preheated so that it becomes soft and pliable. The plastic is then formed around a mold so that it forms a pocket, or cavity, which can hold the product. Once the plastic is cool, it becomes rigid and maintains its new shape. It can then be easily removed from the mold and incorporated into the blister packaging.
If the blister packaging was formed using cold form foil, a stamp pressed an aluminum based laminate film (or cold form foil) into a mold. Blister packs made with cold form foil offer a nearly impenetrable barrier to water and air. This barrier means that they can extend the expiration date of the product, which makes this form of blister packaging extremely desirable when dispensing pharmaceuticals.
If the blister packaging contains cards that have more than one blister pocket, they are referred to as blister cards or blister strips. A blister strip does not always have a plastic cavity. Often, these cavities are formed from and sealed with the same material as the package backing, such as cardboard or aluminum foil.
Some types of blister packaging, such as clam shells, can be extremely difficult to open. Clam shells are formed around a mold of the product they are to contain. Some clam shells do have an opening mechanism on the package, but because one of the primary uses of the clam shell is to ensure tamper resistance, most clam shells do not contain a mechanism that is easy to open. This difficulty often means they are only rarely used in the medical field for unit dose and blister packaging. Instead, they are most commonly used in retail.
Because blister packaging provides some tamper resistance, in the U.S they are primarily used for over the counter pharmaceuticals and for physician samples. The other advantages of blister packaging include the shelf life assurance, ease of single dose packaging and medication management. Blister Packaging.
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