By paying special attention to clean packaging of paper sacks, the product protection offered by paper sacks can even be raised. The ultrasonic sealing technique ensures that paper sacks will not be contaminated during the filling process and no product loss or dust nuisance will occur on the way from the filler to the customers. It is applicable for valve sacks which are equipped with a short outside valve and a sealable coating on the inner valve. After the filling process, the valve is welded by a tool that is attached to each of the filling machine’s spouts: This ultrasonic closing head pneumatically swivels downward and welds the coated paper valve. This process does not prolong the overall filling speed considerably and results in absolutely tightly sealed and clean sacks.

Further advantages of ultrasonic sealing: Thanks to the self-cleaning effect of the weld zone, no subsequent cleaning systems are required. This allows fillers to save plant parts such as spillage and dust collection systems as well as cleaning sets. Moreover, the improved cleanliness leads to lower wear of plant parts and reduced maintenance costs. Since less cleaning and dedusting equipment is needed, the energy costs are reduced as well.

Besides ultrasonic sealing, there are other measures and actions relevant for achieving a high degree of product protection. To find out more, please refer to the “Industry Guidelines for dust-free paper sacks”.