Creating blister packaging involves several steps, from designing the packaging to the actual production process. In this comprehensive explanation, we will explore how blister packaging is made in detail.
Designing Blister Packaging:
The first step in making blister packaging is designing it. This involves determining the dimensions of the blister, the material to be used, and the design of the blister card or backing. Design considerations include product visibility, protection, branding, and functionality.
Materials Selection:
Blister packaging typically consists of two main components:
Blister Cavity: This is the transparent plastic or PVC (polyvinyl chloride) component that holds the product. PVC is commonly used for its clarity and formability, allowing it to be molded into various shapes. Other materials like PET (polyethylene terephthalate) and RPET (recycled PET) are also used for environmental considerations. The choice of material depends on the product's requirements and the intended use.
Blister Card or Backing: This is the printed card or foil that serves as the backing for the blister. It provides support for the product, displays branding and information, and can serve as a tamper-evident seal.
Printing and Design of Blister Cards:
The design of the blister card is critical for branding and product visibility. It can be designed in-house or by a professional graphic designer. Considerations include product images, branding elements, product details, and any required regulatory information. Printing is typically done on sturdy cardstock or foil.
Thermoforming the Blister:
Once the design and materials are ready, the actual blister packaging process begins:
Thermoforming: Thermoforming is the process of heating a plastic sheet (usually PVC) until it's pliable, then forming it into the desired blister shape using a mold. This is usually done using a thermoforming machine. The machine heats the plastic, places it over a mold, and then uses vacuum or pressure to shape it into the blister cavity.
Cooling: After forming the blister, it's essential to cool it quickly to set its shape. This ensures that it retains the desired form and structure.
Sealing the Blister:
The next step is to seal the blister to the backing card or foil. This creates an airtight and tamper-evident package. Several methods can be used for this:
Heat Sealing: This is the most common method. Heat is applied to the edges of the blister, which melts the plastic, creating a seal between the blister and the card. This seal is strong and tamper-evident. Heat sealing is commonly used in the pharmaceutical and consumer goods industries.
Ultrasonic Welding: In some cases, ultrasonic energy is used to weld the blister and card together. This is especially useful for certain plastic materials.
Cold Sealing: For temperature-sensitive products, a cold-seal adhesive can be used to bond the blister to the card without the use of heat. This is often used in the food industry.
Die Cutting and Trimming:
After sealing, excess material is trimmed away, creating the final shape of the blister pack. This can be done using a die-cutting process or, in some cases, using a separate trimming station.
Quality Control:
Quality control is a crucial part of the blister packaging process. Visual inspection is often performed to ensure that the blister is properly sealed and the packaging meets quality standards. Automated quality control systems, including cameras and sensors, can also be used to detect defects.
Packaging Sterilization (Pharmaceuticals):
In the pharmaceutical industry, blister packs may undergo sterilization processes to ensure the safety of the enclosed medications. This is particularly important to prevent contamination.
Final Packaging and Distribution:
Once the blister packaging is ready, it may be further packaged into cartons for distribution and retail. These cartons can be labeled, batch numbered, and stored for shipment to retailers or distribution centers.