Shrink Resisting Wool with Synthappret BAP: The Effect of Drying Conditions

The shrink resistance obtained when the water-soluble polymer Synthappret BAP is applied to wool fabric has been investigated. Particular attention has been given to the variation of shrink resistance with the rate at which the fabric was dried after the polymer had been applied by padding. The adhesion between wool and polymer, and therefore the shrink resistance of the fabric, is strongly dependent on the relationship between the drying rate and the rate at which the polymer reacts. Possible reasons for the dependence of adhesion on drying rate are discussed. The catalytic effect of sodium bicarbonate in curing the polymer is also considered. Under fast drying conditions bicarbonate hindered, rather than promoted, the development of shrink resistance.