Ultrasonic welding is a joining technique that uses high-frequency ultrasonic acoustic vibrations to create a solid-state bond between materials, typically plastics or other porous materials. The process involves applying a rapid oscillating motion at the point of contact between two parts, under pressure, to produce a seamless bond without the need for external adhesives, screws, or heat. The friction generated by the ultrasonic vibrations produces localized heat, causing the materials to soften and fuse together. This method is favored for its speed, energy efficiency, and ability to join materials without compromising their intrinsic properties.