VisioScan Post-seal

Material inspection system for blister web material after sealing.

During the sealing process, pinholes can be created which are usually undetected by in-process-control measures. Those can now be safely detected using the renowned inspection system VisioScan.

Close-up of typical thermoformed blister cards (e.g. PVC) which are inspected by VisioScan Post-seal
Close-up of a relatively large through-hole in the lidding material detected by VisioScan Post-seal and likely caused in the upstream sealing process

VisioScan was developed almost two decades ago to detect pinholes and cracks in the micron range for cold-form aluminum applications. The mechanical impact of forming aluminum foil into pockets sporadically causes tiny holes which are safely picked up by VisioScan. There, it is installed right after the forming station.

Today, the post-seal system performs conceptually the same inspection task, just for the already filled blister web right after the sealing station.

VisioScan can also be used off-line for any blister packs which are subject to potential pinholes. Hence, questionable products can still be released once successfully passing the qualified post-seal VisioScan process.

VisioScan Post-seal insures that during the sealing process no pinholes or micro-cracks in the lidding material have been created. The system scans the complete web material surface from below and can detect damages in the lidding material layer down to 25 μm.

The inspection area can be divided into different zones. Therefore, a targeted reject can be achieved and neighboring areas can continue further in the downstream process.

Application examples

Example: VisioScan Post-seal after sealing station installed on a blister machine
VisioScan Post-seal off-line system for re-inspection of finished blister cards
  • Pinhole inspection for sealed blister web material (plastic forming and aluminum lidding layers) installed after sealing station
  • Pinhole inspection of single finished blister cards

Functional Principle

Conceptual overview of VisioScan Post-seal working principle for sealed blister web/cards

VisioScan Post-seal works on the basis of IR radiation. The system emits IR light using a sophisticated 3-way angled IR transmitter array in order to provide optimal illumination even around the product inside the cavity. Thus, in case of a pinhole in the lid material, the scattered light can enter the receiver of the system.

The receiver part of the system then provides the corresponding result: if the amounts of photons which are passing through an object are exceeding the calibrated threshold, a pinhole is present.

The certified pinhole masks allow the user to set the system sensitivity to a desired size. 

The robust and highly sophisticated light emitter and receiver can be custom designed in size to fit numerous applications and comes standard with a 3 year warranty.


  • Surface inspection of sealed blister web material or single blister cards
  • System for inline or offline applications
  • Inspection down to 25 μm sized holes in post-seal mode
  • Calibration kit with μm-sized and certified pinhole masks to set the system’s threshold
  • Multiple zones can be set to avoid rejection of good product
  • Compact and space saving design
  • GMP compliant