Blister packs protect tablets and capsules individually, make dosing easy and show clearly when a dose has been taken. For pharmaceutical and nutraceutical manufacturers, the blister packing machine is often the final step before cartoning. Understanding how these machines work and what options exist helps companies choose equipment that matches their products and markets.
How Blister Packing Works
A blister packing machine forms pockets in a base material, fills them with tablets or capsules, seals a lidding foil over them and cuts the material into individual blister cards. The process typically includes:
- Heating and forming the base material into pockets
- Feeding tablets or capsules into the pockets
- Inspecting that each pocket is filled correctly
- Sealing lidding foil over the pockets with heat and pressure
- Printing or embossing batch information
- Perforating and cutting blister cards
Types of Blisters
- PVC or PVC/PVDC blisters: transparent pockets with aluminium lidding foil. Affordable and widely used for products with moderate barrier needs.
- Alu-Alu blisters: cold-formed aluminium pockets with aluminium lidding foil. They provide an excellent barrier against moisture and light, suitable for sensitive products.
- Tropical blisters: add an extra aluminium layer to protect PVC blisters in hot and humid climates.
The choice depends on the product’s sensitivity and the markets it serves.
Flat or Rotary Machines
Flat-plate machines form and seal blisters with flat dies. They are versatile, suitable for small to medium volumes and handle a range of materials. Rotary machines use rollers for continuous motion and higher speeds, suited to large-volume production.
Feeding Systems
Tablets and capsules are fed into pockets by brush feeders, channel feeders or specialised feeders for odd shapes. Good feeding ensures every pocket is filled without damaging products.
Inspection
Camera systems check that each pocket contains a correct, undamaged product. Missing or broken tablets trigger rejection of the blister card.
Change Parts
Different tablet sizes and blister formats require different forming and sealing tools. Quick changeover helps manufacturers producing many products.
Hygiene and Compliance
Pharmaceutical blister machines must meet good manufacturing practice requirements, with stainless steel construction, easy cleaning and documentation support.
Integration With Cartoning
Blister machines are often linked to cartoners, which insert blister cards and leaflets into cartons. Synchronisation between machines improves efficiency and reduces manual handling.
Getting Seal Quality Right
The seal between lidding foil and base material protects the product for its entire shelf life. Sealing temperature, pressure and dwell time must suit the materials being used. Too little heat produces weak seals that let moisture in; too much can damage the foil or base film. Leak testing of finished blisters, typically using a vacuum or dye test on samples, verifies seal integrity. Record these checks for every batch. Worn sealing plates or knurling patterns should be replaced promptly, since they directly affect seal quality.
Choosing a Machine
Consider your product types, required barrier, output and number of products. Ask for trials with your tablets or capsules.
Hilden supplies pharmaceutical packaging equipment and can help manufacturers plan blister and cartoning lines suited to their products and production volumes.
