Blister Packaging Machine Product

Overview

A blister packaging machine converts two reels of packaging material and a hopper of tablets into sealed unit-dose blisters — the push-through packs that dominate solid-dose pharmaceutical packaging. The process is thermoform-fill-seal: pockets are formed in a base web, product drops in, a printed aluminium lid is welded over the top, and finished blisters are punched out. Everything happens on one web moving left to right through fixed stations, one format pitch per machine cycle.

An intermittent-motion machine of this class runs about 45 cycles per minute; with a typical 5-up format that is over 200 blisters per minute feeding a downstream cartoner. The stations, in web order: Forming Film Unwind, Forming Station, Feeding System, Inspection System, Lidding Foil Unwind and Sealing Station, Web Indexing, and the Punching Station.

Forming

PVC-based film, usually 250 µm and often barrier-coated with PVdC or Aclar, pays off the Forming Reel Shaft through a Dancer Arm that decouples the continuous unwind from the stop-start web, with the Web Edge Guide holding lateral position. The Preheat Plates soften the film to 120–140 °C by contact, and at the Forming Die a pulse of 4–8 bar air from the Forming Air Valve blows the rubbery film into the chilled cavities; the Die Cooling Circuit circuit freezes pocket geometry on contact. Deep pockets get a mechanical Plug Assist pre-stretch so wall thickness stays even.

Cold-form (alu-alu) packs use the same station differently: the OPA/aluminium/PVC laminate is not heated at all but stretched into the die purely by plugs. Alu-alu gives an absolute moisture and light barrier for sensitive drugs, at the cost of larger pockets, slower indexing, and roughly double the material area per dose.

Filling and inspection

Product flows from the Product Hopper down a Vibratory Chute into Feed Channels that align one product lane over each pocket column. The Brush Box above the web seats tablets into their pockets and sweeps off doubles. Feeding is the format-specific art of the machine: oblong capsules, lens-shaped tablets, and fragile uncoated rounds each want different channel geometry and brush speed.

Every index is then imaged by the Inspection Camera under the diffuse LED Illuminator. The Vision Processor checks each pocket for presence, breakage, and colour, and defective positions are tracked by index count through sealing and punching until the Blister Rejector ejects exactly those blisters. Rejecting after sealing rather than before is deliberate — an empty pocket must never reach pharmacy shelves, and post-seal rejection keeps the web intact through the hot zone.

Sealing, indexing, punching

The printed lidding foil — hard-temper aluminium, 20–25 µm, heat-seal lacquer underneath — merges onto the filled web from the Lidding Reel Shaft, with the Registration Sensor reading print marks so label text lands on the right pocket rows. At the Sealing Plate, a knurled platen at 140–220 °C presses the sandwich against the pocket-relieved Seal Counter Plate for a fraction of a second; the knurl pattern concentrates pressure into a grid of micro-welds, which is why intact blister seals show that characteristic waffle texture. Seal temperature, force from the Seal Cylinder, and dwell are the three validated parameters of the pack, each logged per batch. A Cooling Plate sets the seal before the Draw Rollers, driven by a Servo Motor with Encoder feedback, snap the web forward exactly one pitch.

Finally the Punch Die Set blanks finished blisters out of the web with rounded corners, while the Batch Embosser stamps lot and expiry into the edge and the Perforation Tool adds tear lines on unit-dose formats. Good blisters exit via the Discharge Chute; the lace-like skeleton winds onto the Waste Winder.

Format tooling and compliance

A "format" — forming die, feed channels, seal counter plate, punch tool — is a matched set swapped as a unit in 20–30 minutes. The Machine PLC stores each format's temperatures, pressures, and pitch as a locked recipe, enforces Guard Switches interlocks, and keeps the electronic audit trail (operator, parameter changes, alarms) that pharmaceutical GMP inspection expects from the packaging line's batch record.