Andreas Schneiders, technical sales manager corrugated at Baumer HHS, said, “A lot of the older flexo folder-gluers are still equipped with capacitive sensors for glue or moisture detection. These devices are very sensitive to the fluctuating moisture content in the corrugated board, which is why they tend to operate unreliably and therefore are not really suited to processing corrugated boxes.”
As a result, these capacitive sensors are switched off in practice, meaning that these folding box manufacturers are going without checking glue application.
Schneiders added, “In view of the rising global demands on the quality of corrugated boxes, this is an untenable situation for manufacturers. With the MLT-STA, we have now developed an economical solution that fills this gap and can be retrofitted in flexo folder-gluers without any major expense or effort. Because our MLT-40 is an optical sensor, it is impervious to fluctuating moisture content in the sheets of corrugated board.”
The new system comes with optical MLT-40 multi-bead cold glue sensors which can check up to three glue beads on one or two sides and can verify for any defect in the case of improper glue application on the flaps in the fraction of seconds.
The MLT-STA works in combination with any existing glue extrusion system available on the market. It also checks compliance with prescribed distances from the edge of the glue flaps (edge detection) to prevent any glue coming out of the box when folded. As soon as the error is detected, visual as well as the sound alarm is set on and the MLT-STA marks the defected carton with a UV liquid for easy separation of the defected cartons.
The inspection system generates reports in PDF format for every job and also measures values which can be exported to MS Excel and used for data analysis.
“This low-cost detection system is easy and convenient to set up and operate via touch screen,” concluded Schneiders.