Mainly used in the pharmaceutical, medical, and consumer goods industries, blister packaging is a popular form of packaging many smaller items into one larger package.
The majority of OTC (Over-The-Counter) products are provided in blister packaging for their unit-dose capabilities. Aspirin and other common pills come in what is referred to as a "blister card" or "blister strip" with three or four rows of blister cavities. Packaging companies prefer to use a thin-yet-durable cardboard backing, so consumers can simply push the product through the board and not compromise any of the surrounding seals.
There are two major production types of blister packaging: thermoforming and cold-forming. Thermoformed packaging and cold-formed packaging offer their own different advantages and are created using completely different methods.
As the root of its name suggests, thermoformed packaging is created using heat. A plastic sheet is rolled out and fed into a preheated oven, then brought to a mold. The heated plastic is then pressed into the mold at the forming station using pressure, plugs, and vacuum. It is then cooled so it maintains the new shape as it hardens. More intricate designs may require additional steps, and each packaging company has their own methods and practices to complete these complicated molds.
This procedure of blister packaging does not require the use of heat, and often uses an aluminum-based laminate film, as opposed to plastic. In fact, all that is required is a stamp to press the film into a mold. The pressure from the stamp will shape the film into the desired formation. Cold-formed packaging is highly praised for its use of aluminum, which provides a reliable barrier against oxygen and water. The product can often exceed its expiration date due to the formidable seal from the aluminum.
Although they couldn’t be any more different from one another, thermoformed packaging and cold-formed packaging remain as the top two forms of blister packaging production methods and have been for some while. Both processes are simple, produce desired results, and chances are you have both forms of these blister packaging in your medicine cabinet right now!