Sealing packages with ultrasonics utilizes a vibrating tool rather than hot sealing bars. The advantage: The ultrasonic vibration forces product contamination out of the sealing zone. In addition, the ultrasonic generator can identify bags with irregularities such as folds in the seal area.
For most filling operations, products that are powdery, liquid or lumpy make it virtually impossible to avoid contaminating the seal area with product. When sealing with a traditional heat sealing system, this contamination could result in leakers in which either the seal fails in the autoclave or micro channels appear in the seal area. Bacteria or mold can then penetrate. Sealing with ultrasonics creates reliable seals even in the presence of contamination in the seal area. The ultrasonic vibrations force the product out of the sealing zone while the thermal energy required for the sealing process is produced by molecular and boundary surface friction at the interface of the two layers of film. This produces a high-strength hermetic seal between the polymer layers. When using a Herrmann Ultrasonics (herrmannultraschall.com) sealing solution, the number of leaking packages transported to the autoclave process can be reduced to almost zero. One customer recently shared actual production data that included over 5 days of production with close to 600,000 bags produced with the following impressive result: 100% tightly sealed head seams were achieved using ultrasonics.