Enhanced pleatability of meltblown media by ultrasonic processing

摘要

A process for enhancing the pleatability of a meltblown web uses ultrasonic bonding wheels to create bond lines in the machine direction as the web is being produced. In addition to, or in place of, the bond lines, ribbons made of the web material, a thermoplastic polymer, string saturated with a phenolic or ultraviolet curing resin, or beads of an ultraviolet curing resin may be ultrasonically bonded to the web to enhance its stiffness. A heated scoring bar or ultrasonic horn forms pleats in the web by heating the web above its glass transition temperature and deforming the web into the pleated configuration. Cooling of the web locks the pleats into position.