How strip packing actually works

Strip (or "pillow") packing is a form-fill-seal process: two flat webs of film are fed around a forming station, tablets are dropped into the pocket, and opposing sealing rollers weld the webs above and below each tablet, producing a continuous chain of individual sealed compartments. There is no pre-formed blister cavity and no aluminium base — which is why material cost per unit drops sharply versus blister at scale.

Heat-seal vs cold-seal strip

• Heat-seal: a heated roller bonds a thermoplastic layer (PET/PE or foil-laminate). Lower film cost, needs temperature control; risk of heat-sensitive API degradation.

• Cold-seal: a cohesive (rubber-based) layer bonds under pressure at room temperature. Safer for heat-labile tablets, slightly higher film cost, no thermal risk.

Strip vs blister: measured comparison

The foil-laminate strip reached a WVTR near 0.02 g/m²·day — below most PVC/Al blisters — which is why it is favoured for moisture-sensitive products in the Middle East.

Compliance and climate validation

Strip lines must satisfy EU GMP, FDA 21 CFR 211, CE (Machinery Directive 2006/42/EC) and ISO 9001; device-linked packs add ISO 13485. For humid markets the real test is stability under Climatic Zone IVb (30 °C / 75% RH) — the seal integrity and WVTR must be validated, not assumed. EU-bound packs still need FMD serialisation at the carton level.

Real cases (anonymized)

• Middle East humidity: 500 mg electrolyte tablet, foil-laminate strip at 520 tab/min, WVTR 0.03. Stability at Zone IVb passed where a prior PVC blister had failed at 6 months.

• Southeast Asia generics: high-volume antibiotic, cold-seal strip to protect a heat-labile API; 460 tab/min, lower film spend than blister.

• EU export: heat-seal strip with foil laminate, serialised carton for FMD compliance, 400 tab/min.

Pain points

• Seal integrity in humidity — a poorly tuned roller lets moisture in; validate WVTR.

• Film registration drift at high speed causes mis-seals.

• Heat-labile APIs damaged by hot sealing — use cold-seal.

Misconceptions

• "Strip is the cheap, low-quality option." Proper foil-laminate strip out-protects many blisters.

• "Blister is always better." For high volume in humid climate, strip is often superior and cheaper.

• "Any film works." WVTR is a function of the laminate, not the machine.

Machine differences

Procurement pitfalls

• Specifying "strip packing" without the film laminate — WVTR is bought with the film, not the machine.

• No Zone IVb stability data requested for humid-market export.

• Forgetting serialisation if the pack ships to the EU.

FAQ

Is strip better than blister for humidity?

With a foil laminate, yes — lower WVTR and lower unit cost at high volume.

Heat-seal or cold-seal?

Cold-seal for heat-labile APIs; heat-seal for stable products and lower film cost.

What speed can I expect?

400–600 tablets/min on a modern strip line, above typical blister rates.

Does strip meet EU GMP?

Yes, with CE, validated seals and, for the EU, serialised cartons under FMD.

How do I prove moisture protection?

Request WVTR data and Zone IVb stability validation for the chosen laminate.

Is strip cheaper than blister?

Generally yes at scale — no cavity skeleton waste and lower film mass per unit.

Can strip handle odd-shaped tablets?

Yes, the pocket forms around the tablet; very large or unusually shaped ones need die testing.

What about Middle East SFDA rules?

Meet SFDA GMP alignment and Zone IVb stability; foil-laminate strip is well suited.