Blister

A blister pack is any of 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 or a lidding seal of aluminum foil or plastic. A blister that folds onto itself is often called a clamshell. Blister packs are useful for protecting products against external factors, such as humidity and contamination for extended periods of time. Opaque blisters also protect light-sensitive products against UV rays. Blister packs are used to package products such as toys, hardware, medication, etc. Many blister packaging machines use heat and pressure via a die to form the cavity or pocket from a roll or sheet of plastic. In recent years, improvements in cold forming—specifically allowing steeper depth/angles during forming, which minimizes the amount of material used for each cavity—have helped this technology increase. The main advantages of the plastic-based blister pack are its more compact size compared to cold formed aluminum and its transparency to see the product. Blister packs are commonly used as unit-dose packaging for pharmaceutical tablets, capsules or lozenges. Blister packs can provide barrier protection for shelf life requirements, and a degree of tamper resistance. In the US, blister packs are mainly used for packing physician samples of drug products or for over-the-counter (OTC) products in the pharmacy. In other parts of the world, blister packs are the main packaging type since pharmacy dispensing and re-packaging are not common. A series of blister cavities is sometimes called a blister card or blister strip as well as blister pack. The difference between a strip pack and blister pack is that a strip pack does not have thermo-formed or cold formed cavities; the strip pack is formed around the tablet at a time when it is dropped to the sealing area between sealing moulds.