What is tamper-evident labelling?
Tamper-evident labelling uses a label or seal designed to provide visible evidence when someone has interfered with, opened or attempted to remove it from a product or package. The purpose is to make interference detectable rather than to make the pack impossible to open.
The label normally works together with the pack design and its closure or access point. Depending on the construction, attempted removal can damage the label, leave a visible mark or reveal a message or pattern that cannot be returned to its original appearance.
At a glance:
- Tamper-evident labelling provides visible evidence that a label, seal or package closure has been disturbed.
- The label is normally positioned where opening or access will break, lift, damage or visibly change the tamper-evident feature.
- Some pressure-sensitive constructions reveal a message or pattern when someone tries to remove or reapply the label.
- Tamper-evident does not mean tamper-proof: the objective is to reveal interference rather than guarantee that opening cannot occur.
What does a label applicator do in a labelling system?
A label applicator applies a pre-printed pressure-sensitive label to the product or pack. This application function is separate from printing, which matters when defining whether the requirement is to apply an existing label, print variable information, or combine printing and application.
For tamper-evident labelling, placement is particularly important. Depending on the pack design, a tamper-evident label may need to bridge a lid, flap, seam, cap or another access point so that opening or attempted removal produces the intended visible evidence.
The label construction and the applicator therefore need to be considered together with the pack geometry and required label position. A particular applicator should only be selected after the tamper-evident label format and application requirement have been established.
Where does labelling sit in end-of-line operations?
Tamper-evident labelling normally takes place when the product or package is sufficiently closed and presented for the label to be applied in its required position.
On an automated production line, conveyor systems and product-handling equipment can present the pack consistently to the labelling point. The labeller then applies the label or seal across the specified area.
Vision inspection can follow as a separate control where the line needs to check label presence, position or other defined quality requirements.
This makes product presentation more important than simply getting a pack past the applicator. If the tamper-evident label needs to bridge a particular closure or seam, the pack needs to arrive at the application point in a repeatable position.
Which factors matter when selecting a labelling system?
For a tamper-evident application, inputs used to specify automated labelling systems need to be combined with requirements specific to the seal, closure and visible tamper indication.
Product and pack format and label position
Start with the part of the package that needs tamper evidence.
Identify how the pack is opened and where the label needs to sit so interference with that access point produces the intended visible change. The required position could involve a closure, lid, flap, seam or another part of the package.
Pack dimensions and geometry also affect how the product is presented to the labeller and whether the required area can be reached consistently during automated application.
Line speed, environment and integration
The tamper-evident construction must work on the actual surface to which it will be applied. Adhesive performance can be affected by factors including the substrate material and texture, surface energy, cleanliness, temperature and the time allowed for the adhesive bond to develop.
Application testing is therefore important before committing to production.
Once the label material and required position are established, normal system-design inputs such as production rate, existing equipment and integration requirements can be used to determine how the application fits into the wider line.
Inspection requirements and product handling
Product handling should present the package consistently enough for the tamper-evident label to reach its intended position.
Inspection is a separate requirement. If the production process needs confirmation that the label is present or correctly positioned, that requirement should be specified independently rather than assuming the applicator itself performs the check.
The required tamper indication should also be defined before equipment selection. For example, the application may call for visible label damage, a transferred mark or another evidence mechanism when removal is attempted. Different label constructions achieve this in different ways.
ALS Identify labelling-system planning for tamper-evident labelling
ALS Identify designs and integrates labelling systems for production-line applications. Its solution selector includes tamper-evident labelling among the application options and captures details such as product format, dimensions, label position and related integration requirements.
Use the ALS solutions selector to record the basic application details, then discuss the label construction, pack closure and production-line requirements with the team.
