Label sensor guide for front and back labelling machines

Why sensor choice matters

A labelling machine must detect the label reliably before applying it to the pack. If the sensor cannot identify the label edge or gap, label position can drift or the machine can misfeed.

Sensor choice is especially important for clear labels, thin film labels, reflective labels and unusual backing materials.

• Opaque paper labels are usually simpler to detect.
• Clear labels may need ultrasonic or specialist sensors.
• Reflective or metallic finishes should be tested before specification.

Clear label detection

Clear labels can create a premium no-label look, but they can be harder to detect than opaque labels. The label and backing combination should be checked before machine selection.

Where possible, provide sample rolls or detailed material specifications so the correct sensor route can be confirmed.

• Label material and liner material.
• Gap size and label thickness.
• Bottle material and background at application point.

Product detection and label placement

The machine also needs to detect the container or product. Product sensors, label sensors and the machine control system work together to position the label.

Transparent containers, very dark containers or unusual shapes can affect product detection and should be mentioned early.

• Container colour and transparency.
• Shape, width and detection face.
• Position of front and rear labels.

What to send for sensor checking

A sensor decision is easier when the pack and label details are supplied together. This prevents a quote from assuming a standard opaque label when the project actually uses a more demanding material.

• Label sample or material specification.
• Photos of bottle and label position.
• Label gap, roll direction and backing details.
• Target speed and label tolerance.