Method of ultrasonically bonding nonwoven webs

摘要

Improved method of forming bonded web laminates by application of a liquid spray between the component layers prior to application of high frequency vibrational energy commonly referred to as "ultrasonic energy". The liquid is preferably water and added in a minor amount, preferably less than about 25% by weight of the combined webs. The water may be added by spraying or misting and, after bonding and drying, provides improved uniformity and web bonding while allowing increased bonding rates. The method of the invention is particularly useful with heavier basis weight thermoplastic polymeric nonwoven fiber webs to be combined for durable applications such as recreational fabrics for tents and the like.