Ultrasonic nonwoven bonding

Abstract

A method of forming an improved, nonwoven lightweight (about 3 oz./yd..sup.2 or less) fabric from a batt of random, loose ultrasonically fusible (i.e., thermoplastic) fibers. A product is produced by utilizing an ultrasonic welding machine having a patterned roll anvil or equivalent, and a horn, and a carrier of flexible sheet material such as tissue paper, heat transfer print paper or other nonthermoplastic sheets, capable of drawing and spreading out ultrasonic energy from the machine. The batt and the carrier are disposed in face to face abutting relationship and are progressively fed together between the horn and the anvil of the machine while supplying ultrasonic energy to the batt with the machine sufficient to form the batt into a nonwoven fabric. The carrier may be disposed against the horn or against the anvil depending on the particular carriers and batts used, and for a given carrier and batt the formed nonwoven fabric will have slightly different properties depending upon whether the carrier is against the horn or the anvil. When heat transfer print paper is used the nonwoven fabric is heat set before separation from the paper, and a printed nonwoven fabric results. Decorative nonwoven fabrics may also be produced by disposing contrasting fibers on the batt before feeding to the machine.