Spreading and imbibition of durable press reagent solutions in cotton-containing fabrics

Incomplete spreading and penetration of durable press reagents during low pickup finishing of cotton textiles result in poor distribution of reagent residues, which adversely affects textile performance. To assess those properties of fabric and solution that affect spreading and penetration, drop absorbancy time (DAT), vertical wicking distance (VWD), and saturation value (SV) were determined. The solution-holding capacity of the fibers in the fabrics was assessed via solution of imbibition (SI). The durable press reagent systems studied contained DMDHEU, MgCl 2·6H2O, and the wetting agent Silagen MA alone and in combination. The fabrics included a series of all-cotton Osnaburg-type fabrics, in which the fill thread count was increased incrementally, and a series of intimate blend sheetings with a range of cotton/ polyester ratios. Enhanced spreading, as indicated by decreasing DAT and SV and increasing VWD, was associated with increasing fill thread count in the all-cotton Osnaburgs, decreasing cotton content in the blend sheetings, and the inclusion of the wetting agent Silagen MA in the test liquor. Depressed spreading was associated with increasing solids concentration, which increases solution viscosity, and with inclusion of the MgCl2·6H2O catalyst. The SI of the fabric was increased by increasing the cotton content and by increasing the DMDHEU content of the liquor. The latter is attributed to an increase in solution density.