Ultrasonic Sealing

The ultrasonic sealing process becomes more important in comparison to the conventional heat sealing method and it is advantageously in a multitude of applications, especially in the food industry. Some of the practical proven benefits are e.g. short process times, high energetic efficiency, insensibility towards seal-contaminations, the possibility of cooling the seam during the sealing process and the potential for inline quality control. The lack of basic knowledge about the behaviour of packaging materials at the ultrasonic sealing process complicates an efficient process control for the user.

For the ultrasonic sealing process other material properties are relevant in comparison to the heat sealing process, based on the different active principle. Those material properties have an important influence in the seam quality and process efficiency. Available sealing materials, mostly polyolefin-based, are generally optimised for the heat sealing process. The experience shows that the ultrasonic sealing behaviour can be completely different compared to heat sealing behaviour.

During the research project the following deliverables are aimed:

• Investigation about the influence of material properties from single layers in multi-layered films in the ultrasonic sealing process
• Detection of material properties, which mostly influence the ultrasonic sealing process
• Discovering process parameter fields and establishing an user recommendation, respectively a guideline
• Deployment of a basic model approach to describe the ultrasonic sealing procedure

The research about the most relevant, respectively the most benefiting material parameters and combinations in the ultrasonic sealing process, will allow the film producers a better adjustment to this seal method. Furthermore, the aspired results will give the users a higher process stability, higher reachable process velocity and lower down and set-up times. Machine constructors and film producers can minimize their development time of special optimised tools and films and get essential cost-saving potential.