Double-leaflet check in cartons
Before its flap is closed, the carton passes under a laser profile sensor. In the cross-section taken through the carton mouth the leaflet fold ridges are counted and the pack thickness is measured; a carton holding two leaflets is removed from the line.
Ridge count and pack thickness are logged per carton; a carton with a double or missing leaflet is blown into the reject bin before the flap closes, and the result is shown on the stack light.
- 01 Infeed
- 02 Laser profile
- 03 Fold count
- 04 Decide
Cartons with their top flap open approach the sensor at constant speed; the photo-sensor sees the carton and profile acquisition starts.
- Fold ridges
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- Pack thickness
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- Leaflets
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Scenes are illustrative simulations; they are not customer references or performance guarantees.
Need
The leaflet is thin and white; the blister and the inside of the carton are white too, so the number of folds does not separate by contrast in a 2D image. Two leaflets lean against each other, and the only difference is a few millimetres of thickness and two extra fold ridges.
Solution approach
The laser profile sensor projects a line across the carton mouth and reads the height profile; colour and contrast do not matter, only geometry is measured. Profile acquisition starts when the photo-sensor sees the carton. Fold ridges are counted as peaks in the profile and the distance between first and last ridge is the pack thickness; both values are compared with the single-leaflet reference.
Process steps
- 01
Infeed
Cartons with their top flap open approach the sensor at constant speed; the photo-sensor sees the carton and profile acquisition starts.
- 02
Laser profile
The laser line crosses the carton mouth; content height is captured as a profile.
- 03
Fold count
Fold ridges in the profile are counted and the thickness across them is gauged.
- 04
Decide
Ridge count and thickness are compared with the single-leaflet values.
Related applications
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