The sealing bar and/or counterpressure bar are dirty or covered by liquid residues.
Clean and dry the sealing bar and/or counterpressure bar.
The weld seam is faulty or not properly sealed in one or more places.
Clean and dry the sealing bar and/or counterpressure bar.
Flatten the rubber.
For a perfect weld seam, the edge of the bag must be dry and grease-free in the area of the seam.
Fold the edges of the vacuum sealing bag outward for filling.
This will give you a clean weld seam.
Position the edge of the bag smoothly and without creases along the sealing bar.
Wait a minimum of 2 minutes between individual vacuum sealing processes.
This prevents the sealing bar from overheating again.