Fabric protection, bleaches

Chelants in bleach-activated powder laundry detergents have a number of key roles to play - bleach stabilization, dye and fabric protection, stain removal, and scale inhibition. 

Perkins, H.M., Rigakis, K.B., and Crown, E.M., The efficacy of bleach pre-treatments in chlorpyrifos residue removal from cotton workwear fabric, in Performance of Protective Clothing Fourth Volume, ASTMSTP 133, McBriarty, J.P. and Henry, N.W., Eds., 1992, pp. 799-810. 

Polymeric dispersant and protective colloid for yarn and fabric preparation and bleaching. Minimises scale build-up on hot metal surfaces and fabric. Extremely efficient dispersant for cotton linters and particulate soil. Provides a cleaner fabric after washing-off without drainage marks. Improves absorbency and dyeing properties. 

Mercerization improves dimensional stability of cotton woven fabrics [63]. When knitted fabrics are compared with respect to their relative openness, temperature increases can be said to improve mercerization because when the goods are bleached and then mercerized, the fabric becomes more dense. However, when unbleached fabrics are mercerized, the fabrics become more open [64]. Mercerization also gives moderate improvement in crease recovery of cotton fabrics [65] as well as some protection against the decrease in tensile strength caused by easy-care finishing. 

Liang et al. (2006) ° developed a novel hydantoinylsiloxane that could be used to functionalize silica gel for use as a biocide upon exposure to dilute household bleach. The hydantoirtylsiloxane could be used in either monomeric or polymeric form. The authors covalently bonded hydantoinylsiloxane to the silica gel, and proved that the coated silica gel particles, upon exposure to household bleach, were able to inactivate Staphylococcus aureus and Escherichia coli. The authors also claim that the coatings are stable to flowing water and can be rechlorinated if the oxidative chlorine is lost during activity. Such coatings could be conveniently employed in protective fabrics. ... 

Treatment of wool with a FWA, followed by post-treatment with thiourea/formaldehyde by a pad/cure method, confers a high level of protection against photoyellowing and also improves the initial fabric whiteness (134). Unfortunately, this process is not commercially viable, partly because of environmental concerns about thiourea and formaldehyde and also because much of the benefit is lost after laundering. An alternative approach is to physically separate the FWA from the wool fiber by incorporating the whitener into a suitable polymer that can be applied as a surface treatment to wool fabrics (135). The photostability of the treated fabrics is somewhat better than for conventional FWA treatments (being similar to bleached wool) but the initial whiteness is significantly lower than that of FWA-treated wool. 

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