Ultrasonic bonding is convenient, but it has a limitation. The side seams near handles can be weaker than sewn seams. When a bag is overloaded, the ultrasonic weld may break under tension.
This happens because ultrasonic bonds fuse only the surface layers. While adequate for light loads, heavy items put stress on the edges. Manufacturers often suggest checking the bag’s weight capacity before use.
For shoppers, this means avoiding overloading bags with heavy items. For businesses, reinforcing the handle area or using thicker fabric can improve durability.
