1. Milk cartons are common packaging containers in daily life for holding liquid beverages such as milk. They usually use multi - layer composite paper packaging materials, which have good barrier properties and can effectively prevent the intrusion of oxygen, light, and microorganisms, thus extending the shelf - life of milk. The design of milk cartons also attaches great importance to convenience and aesthetics, and common shapes include gable - top cartons, Tetra Pak cartons, etc.

2. In the production process of milk cartons, for milk cartons, ultrasonic welding can achieve rapid and firm sealing, ensuring the tightness and safety of milk cartons. Moreover, this welding method does not produce harmful substances and meets the hygienic requirements of food packaging.