- Individual foil packaging with variable geometries
- Medical packaging
- Pressure tank or valves for propellant gas or compressed air
Laser welding of plastics in packaging only makes sense if specific advantages of the laser technology are of decisive importance. For example the flexibility of the welding contour for individualized packaging or the cosmetic exterior without marks from the welding. If propellant gases or compressed air are used in spray cans or dispensers, particle-free welding can also be important to avoid nozzle blocking.
As packaging films have to be transparent often or the price of the laser-absorbing dye can be an issue, the heat-through process is an attractive alternative. However, it is only suitable for thin films and is relatively slow.
Packaging foils often consist of several layers with different functionalities. On the one hand, this has the advantage that the laser-absorbing dye only has to be introduced into one layer, but on the other hand it must also be taken into account which sides of the foils are joined together.
If metal foils and cardboard have a plastic coating, they can also be joined by laser welding, for example for medical packaging or food.
For most other applications in the packaging industry, heat sealing with contact heat from hot bars is primarily employed. This cost-effective technique is established for many simple applications with foils and can also be used with short cycle times. In addition to heat sealing, ultrasonic or high-frequency welding is also used to a small extent for packaging foils.