Air Permeability of Treated Fibrous Materials with Bicomponent Fibers

The influence of roller temperature and treatment rate of fabrics of various surface densities based on a mixture of poly(ethylene terephthalate) and bicomponent fibers on the air permeability of the materials was investigated. The permeability decreased for fabrics with surface densities from 0.15 to 0.25 kg/m2 for various roller temperatures if the treatment rate was decreased from 10 to 2-4 m/min although it began to increase if the rate was reduced further. The permeability of fabrics with surface density 0.4 kg/m2 decreased constantly if the treatment rate at various roller temperatures was decreased. The dependence of the permeability on the structure of a modified layer of fabric in which the fibers reoriented with increasing filtration resistance during the treatment was determined from the relationship between the change of permeability and porosity of treated materials. Defects in the layer with increased permeability appeared for fabrics of low surface density at slow treatment rates.