Análise comparativa da eficiência do peróxido de hidrogênio e hipoclorito de sódio na remoção de manchas em tecido jeans.

Abstract

The usage of stain removers for clothing is widespread in society and has high penetration in Brazilian homes, due to both variety of brands and its reasonably affordable prices. In this context, sodium hypochlorite, commercialised as “bleach”, ranks among the most used bleachers, although it commonly damages jeans fabric fibres, 90% composed of cotton. Therefore, the aim of the study was to compare the efficiency in stain removal from jeans fabric of sodium hypochlorite with that of hydrogen peroxide. Motivation for studying the theme originated from researcher’s professional background in cleaning services business, during which it was observed that hydrogen peroxide may have an equivalent or superior capacity of stain removal in comparison to bleach, besides preserving fabric original characteristics such as colour and elasticity. In order to analyse this proposition, the study used 21 samples of jeans cloth which were stained with lipstick, chocolate and coffee, then divided into 3 groups: those soaked in sodium hypochlorite solution, those soaked in hydrogen peroxide solution and those soaked in only potable water. Sodium hypochlorite and hydrogen peroxide solutions had 3 different concentrations (1:15, 1:30 and 1:60), whose purpose was to evaluate if stain removal and fabric characteristics preservation were concentration-dependant. Fabric samples that were soaked in hydrogen peroxide had better results in the removal of 3 stain types in comparison to sodium hypochlorite. Best results, in both cases, occurred under a concentration of 1:15. The stain type most sensitive to bleaching was that from coffee, whereas lipstick stain showed higher persistence in all cases. Concerning fabric appearance, samples treated with hydrogen peroxide suffered a lower degree fading, whereas those treated with sodium hypochlorite lost original tones and showed greater fragility, inflicting damage to fabric fibres. It may be concluded that hydrogen peroxide is an effective stain remover for jeans fabric, of better performance than sodium hypochlorite, and shows a bleaching power which induces less damage to fabric fibres and preserves its colour and elasticity. Best result was achieved at a concentration of 1:15.