PROTECTING COLOURS n Why protect colours: –because bright colours need to keep bright? –because dark colours will last longer? –because it gives confidence to the consumer?

What affects colours during washing? n Loss of loose dye on fibre (reactive dyes, vat dyes,etc) n loss of dye of low affinity (direct dyes, acid dyes, disperse dyes) n deterioration of dye by use of chlorine bleaches n deterioration of dye by use of peroxide bleaches, making the colours duller or weaker

Peroxide attack n During washing n by perborates, percarbonates, peracids n at 60ºC with detergents containing sodium perborate n at 40ºC and below with detergents containing perborate activators, such as T.A.E.D.

Dyes sensitive to peroxide attack n most sulphur dyes (5-10% dyes on cotton) n most reactive dyes (70-80% of dyes on cotton) n Some acid dyes on Nylon

AVOID PEROXIDE ATTACK n Use peroxide free detergents n use dyes that are not sensitive n use colour protector

Peroxide free detergents n Do not bleach textiles as efficiently n Do not clean as effectively n Do not kill bacteria as efficiently

Separate sensitive dyes n Not practical to separate sensitive colours from safe colours n don’t know which colours are sensitive n reactive and sulphur dyes are the most used dyes in cotton and acid dyes the only dyes used on Nylon

Colour protector-1 n Works at all temperatures (with or without TAED) n Concentrations : –based on the perborate concentration because it is a free radical quencher, so it is dependent on the peroxide concentration and not on the dye concentration –tested successfully at concentrations of 25% of perborate concentration(without microencapsulation)

Colour protector-2 n Works at all temperatures (with or without TAED) n Effective at lower concentrations : –Based on the concentration of perborate as it is a singlet oxygen quencher –Tested successfully at concentrations as low as 20% the perborate concentration (microencapsulated)

Suggestions for its application n Mixed with the detergent n Mixed with the bleach n As a separate detergent additive

Wash fastness tests n n 1,0 g/l sodium carbonate + 2,0 g/l sodium perborate+ 4,0 g/l detergent ECE + quencher 1 at 0,5 g/l concentration n n washing test: reagents added and dissolved at 40ºC, wash liquor heated to 60ºC, kept at 60ºC for 30 minutes

RESULTS n n Above 0,5 g/l the protection effect to perborates is maximum n n Dyes tested successfully Reactive Dyes Levafix Orange E3GA Levafix Golden Yellow EG Remazol Red RB Procion Yellow HE6G Cibacrone Blue FGF Sulphur dyes Hydrosol Black B