No abstract

SynopsisThe reactivity of scoured Acala 4-42 cotton before and after treatment with alkaline and acid swelling agents has been msessed by a number of methods. It is shown that the reactivity depends more on the type of swelling, whether it is interfibrillar or intrafibrillar, than on the degree of swelling achieved. Furthermore, the reactivity of the treated cotton depends on whether the reaction is carried out in a nonswelling or a swelling medium. Thus high intrafibrillar swelling can lead to a loss in reactivity of the treated cotton if the subsequent reaction takes place in a medium incapable of swelling the treated cotton, on the other hand, interfibrillar swelling can lead to an increase in reactivity in the same reaction mixture.

Early work at the Shirley Institute showed that light fading and tendering of dyed cotton fabrics are affected by the type of light, the humidity, and the presence of metals. More extended exposures under controlled humidity conditions show that many vat and azoic dyes decrease in fastness with rise in humidity. There is also a relationship between the amount of fading and the degree of photochemical damage to the fibre and this effect is pronounced with yellow, orange, and red dyes. Some observations are included on north‐ and south‐facing exposures on dyed cotton and other fibres.