What is Blister Packaging?
Blister packaging is a type of pre-formed plastic packaging used for consumer goods, food, and pharmaceuticals. It consists of two primary components:
A Cavity or Pocket (the "Blister"): Made from a transparent plastic sheet that is thermoformed to hold the product securely.
A Backing Material: A sealed lid, typically made of paperboard, foil, or plastic, that encloses the product within the blister cavity.
The product is visible and protected within the blister, and the backing is often printed with product information, branding, and usage instructions.
Key Components & Materials
1. The Blister (Forming Film)
Materials:
PVC (Polyvinyl Chloride): The most common and cost-effective option. Offers good clarity and rigidity. However, it has poor barrier properties against moisture and oxygen and environmental concerns have reduced its use.
PVDC-coated PVC: PVC coated with Polyvinylidene Chloride to significantly improve its barrier properties against moisture and oxygen, making it suitable for moisture-sensitive pharmaceuticals.
Aclar (Polychlorotrifluoroethylene - PCTFE): Provides an exceptional moisture barrier, superior to PVDC. Used for highly sensitive drugs and electronics.
PET (Polyethylene Terephthalate) & PETG (Glycol-modified PET): Offers excellent clarity, rigidity, and chemical resistance. PETG is easier to thermoform. They are more environmentally friendly than PVC.
PP (Polypropylene): Good moisture barrier and chemical resistance. It is a popular choice for "push-through" packaging due to its flexibility.
PE (Polyethylene) & APET (Amorphous PET): Also used for specific applications.
2. The Lid (Lidding Material)
Materials:
Paperboard: Often used for "clamshell" style packaging or where the product is not pushed through but rather torn open.
Foils: Typically aluminum foil. The standard for pharmaceutical "push-through" blister packs. The foil is almost always coated with a heat-seal lacquer on one side to bond to the blister and printed on the other.
Peelable Films: Multi-layer laminates of paper, plastic, and foil that allow the consumer to peel open the package easily.
The Manufacturing Process
The creation of blister packaging is a high-speed, automated process with four key stages:
Thermoforming: A roll of plastic film is fed into a machine and heated until pliable. It is then vacuum-formed or pressure-formed over a mold (tooling) to create the specific cavities (blisters) that will hold the products.
Product Loading: The products are automatically or manually placed into the formed blisters.
Lidding & Sealing: The lidding material (e.g., foil) is placed over the filled blister sheet. A heated plate applies pressure and heat to seal the lidding to the flanges of the blister cavities, creating a hermetic seal.
Die-Cutting & Trimming: The large sealed sheet is die-cut into individual blister packs or strips of packs. The excess material (skeleton) is trimmed away and recycled.
Types of Blister Packs
Face Seal Blister: The blister card is printed, and the clear blister is sealed directly onto the printed surface. Common for low-cost hardware and toys.
Trap Blister (or Clamshell): The blister is sealed around the product and a printed card, "trapping" the card behind the product. This provides more space for graphics and information. Very common for retail items.
Slide Blister: The product is placed on a card, and a blister is sealed over it. The entire unit is then placed inside a sleeve, allowing the product to be slid in and out.
Full-Face Blister: The blister covers almost the entire front of the card, maximizing product visibility.
