Effect of friction coefficient of white cloth on rub-fastness

Abstract

Rub-fastness of dyed fabrics is a matter of importance for practical use. Generally speaking, vat and naphthol dyes tend to suffer from poor rub fastness. However poor it is, it depends on the friction coefficient between dyed fabric and rubbed cloth. That is, smooth one should have good rub-fastness. In this paper rubbing-off behavior of denims using various white cloths is investigated from the kinetic viewpoint so that the interesting results are obtained. That is, the values of the rate constant k1 of transfer of dye from dyed fabric to white cloth and the equilibrium constant K (k1/k- 1) are ranged about ten times by various white cloths. These values depend on friction coefficient of white cloth, with having nothing to do with variety of fibers, fabrics and so on. Natural logarithm of each constant is linearly related to the reciprocal of friction coefficient. It suggests that the measurement of friction coefficient should be effective for standard of rub-test in addition to a designation of cloth or adjustment of moisture regain.