Blister packaging is so named because the little pockets in the package look like little blisters. This form of packaging is often used with gum, candy, and medicine, and usually has plastic pockets that hold the pill with a foil backing. To remove the pill, all you do is push the flexible blister to pop the pill through the foil backing. Some medical blister packages do not have the push through option, to keep sanitation a high priority. This is done by keeping the item contained until use so the administrator never has to touch the sterile surface of the object.
Blister packaging companies have two main methods of creating blister packages for medicine or candy. The packages can be formed through thermoforming or cold forming. Different blister packaging companies have different packaging methods based on the needs of their particular clients. The process of producing the blister packages is generally the same, but there are key differences in the two forming methods.
Thermoforming: In thermoforming, a plastic sheet is unrolled from a large roll of plastic and heated on a production line. The warm plastic is pressed with a pressure bar that forms the pockets in the blister pack. The plastic is then cooled quickly to retain the blister shape.
Cold forming: In cold forming, the plastic is never heated. Rather, the plastic strip is pressed into the desired shape using the pressure of a large stamp, which forms the blister packets. In cold forming, usually aluminum-based plastics are used, which extend the shelf life of the products. However, this kind of forming is slower than thermoforming and usually the blisters are opaque or only semi-transparent, which can be a drawback. Only larger blister packets can be formed using this method, as the stamping machine cannot form smaller shapes.