A method for manufacturing absorbent sanitary products, comprising the steps of: forming a first and a second continuous elastic band, which are movable parallel to each other in a machine direction, fixing a plurality of absorbent panels between said first and second continuous elastic bands, arranged in a direction transverse to the machine direction, and spaced apart in said machine direction, wherein each of said elastic bands is formed by means of a method comprising the steps of: continuously feeding a plurality of tensioned elastic threads (30) in said machine direction, continuously feeding a pair of non-elastic webs arranged on opposite sides of said plurality of elastic threads, welding said pair of non-elastic webs to each other by means of a welding pattern comprising anchoring welds and/or containing and guiding welds.

A system for ultrasonic or vibration welding, staking, swaging, forming or degating of a thermoplastic workpiece includes a vibratable horn having a face, a thermoplastic workpiece, and a vibratable tool positioned between the vibratable horn and the thermoplastic workpiece. The system is configured to energize the vibratable horn to transfer energy from the vibratable horn through the vibratable tool to the thermoplastic workpiece to induce welding, staking, swaging, forming or degating of the thermoplastic workpiece. Optionally, the upper and/or lower surfaces of the vibratable tool may have three-dimensional contour(s) that are complementary to three-dimensional contour(s) of the vibratable horn and/or the thermoplastic workpiece. Additional systems and methods for ultrasonic or vibration welding, staking, swaging, forming or degating of a thermoplastic workpiece are also disclosed.