Vapor-Phase Ozone Treatment of Wool Garments

Abstract

Optimum treatment parameters for ozone-steam shrink-resisting of wool fabric and garments, hung in a chamber, were determined. Circulation of the vapor around the materials is necessary for rapid reaction. Fabric construction in; fluences the shrinkage control achieved; tight construction apparently limits the rate of diffusion of ozone into the fabric. Ozone consumption is low, (1.2% owf or less). Wool and lambs-wool sweaters were made shrink-resistant in a single-sweater batch treatment chamber. In batch treatments, since a large percentage (75 to 80%) of the injected ozone is exhausted unreacted from the chamber, excessively large and expensive ozone generators are required. Furthermore, these generators consume-excessive electricity (energy), and the excess ozone must be destroyed. Therefore a process was developed to utilize ozone efficiently. In this new process, garments are continuously moved through an open-ended tunnel; the ends are sloped downwards to confine the hot gasses. Ozone is injected at the center so that nearly all of it is consumed during its movement towards the ends. A pilot-scale continuous treater was constructed that utilizes 94% of the injected ozone; treated fabrics have excellent shrink resistance. The ozone-steam process has advantages over other shrink-proofing processes in that (1) no pre-wetting or post-drying stages are required (low energy requirement), (2) it is a continuous, single-stage process, (3) excellent, uniform shrinkage control is attained without significantly impairing fiber properties, and (4) treatment costs are low (efficient ozone utilization).