Dingy Test Fabrics

BACKGROUND

The "clean" fabric wearing by consumers is not clean, it is a dingy fabric. After the first cycles of washing/drying/wearing, some level of body and ambient soil redeposition occurs as well as fabric become yellowished due to a light induced loss of fluorescence. This clean dingy fabric becomes soiled or stained during consumer wearing. Worn garments are considered soiled by the consumers if a general appearance is different to the original clean status, usually a yellowish or greyish cast is easily detected visually in all garment which is corroborated by smell evaluations. Worn garments are considered stained when a extraneous material-coloured area is easily detected visually; some garment areas typically checked looking for stains are among others: knees areas, front areas, collar and cuffs, arm pits, and pants bottom areas.

After some laundry process, washed fabrics are visually evaluated by consumer to assess the quality of the process (and of course laundry products quality). That group of visual perceptions depends on several factors but fabric original level and type of dinginess plays a critical role for whiteness perception after one or multiple washing cycles as well as for the capability to detect remanent stained areas. For this obvious reason in line with laundry market, up to date detergency studies have been discarded the conventional use of test monitors based on technical substrates with no relevance with market realities and unusable to mimic visual consumer perceptions.

DINGY-CL™

Clean dingy test fabric with deposited body and ambient soils, and light-induced yellowished

A clean dingy fabrics, that represent not-new-garments ready to wear (not ready to wash). Yellowish, reddish, greenish, bluish or greyish shaded fabrics according to specific market realities.

Commercial white cotton or poly/cotton fabrics are pre-treated to remove impurities, then they are washed under adverse conditions with a washing liquor containing body and ambient soils. After each washing cycle, usually ten, fabrics are dried under full controlled natural sun radiation until a fixed UVA radiant exposure. Finally, fabrics are post-treated to remove dust. Different shades on test fabrics are obtained using coloured natural clays during washings and/or common pigment found in laundry products.

Rested on modern spectrofluorimetric techniques for fabric characterisation, each market reality is matched by careful control of fabric's:
..... loss of fluorescence due to drying/wearing outdoors,
..... loss of base white due to soil redeposition, and
..... presence of shades due to specific ambient soils and/or specific pigments during washing with pigments-containing detergents.

DINGY-CL, is typically used as a substrate to produce in-house stained test fabrics for detergency analysis. It is also used as a such on whiteness perception studies based on multiple cycles of washing/drying.

DINGY-SD™

Soiled dingy test fabric with body and ambient soils

A uniformly soiled dingy test fabrics that represent soiled worn garments ready to wash (not ready to wear). Yellowish or greyish cast is applied onto a shaded dingy fabric DINGY-CL.

In just one step a clean dingy fabric DINGY-CL is soiled uniformly with a combination of fresh body and ambient soils. All fabric shows a yellowish or a greyish cast pending on the combination of clays used in the process.

DINGY-SD, is typically used on detergency studies of cleanliness perception concerning general soil remotion after the first wash. Additionally it is used as a substrate to produce relevant in-house standard stains for detergency analysis.

DINGY-TN™

Stained dingy test fabric with relevant coloured stains

A dingy test fabric with localised stained areas that represents stained worn garments ready to wash (not ready to wear). Several relevant stains are applied manually at real concentrations levels onto shaded dingy fabrics DINGY-CL. A version of stained areas onto DINGY-SD is also offered.

Unlimited hydrophobic and hydrophilic stains, with different origins, are applied manually on DINGY-CL or DINGY-SD test fabric following market parameters. Collar and cuffs stain is also simulated with a mixture of components of four groups: sweat gland secretions, sebaceous gland secretions, dead skin cells, and ambient dust.

DINGY-TN, is typically used on cleanliness perception studies concerning specific stain removal performance after the first wash. It simulates, in extend, the interaction of remanent stained areas with adjacent fabric on final cleanliness perception.

ORIGINAL:

WASHED:

A very special case: The Collar and Cuffs Stain

Consumer cleanliness assessment of laundry product is not the same around the world, but it has been found that some washing problems are nearly the same despite different cultures and habits. Consistently, remotion of easily perceived stains present on white collar and cuffs constitute one of the icons linked to final consumer value delivered by laundry products.

Unfortunately this simple cleanliness perception fact from the consumer point of view, is a very complex process from the R&D perspective, not only due to the complexity of the inorganic and organic constituents of the stain, but also due to the interaction of different fabric surroundings (the area in direct contact with the skin and the rest of the collar area) on final consumer cleanliness perception.

Our approach, a special constructed double-layered test fabric with different dingy surroundings that simulate a worn white collar, with two areas of fresh stain that mimic the combination of body and ambient soil. Clean and soiled dingy fabrics of the monitor can follow different market realities, see photo:

QUALITY CONTROL AND DURATION

In order to ensure quality, test fabrics are subject to an instrumental evaluation control when each batch of fabric is completed; it is done according to the amount of fabric, which is recorded on a control chart. Coefficient of variance of less than 5% is guaranteed.

The fabric should be stored in a dark place and at low temperatures (approximately 5°C). It is also recommended that the package be opened only when tests are to be conducted. Under these conditions, the fabrics will have a twelve-month life expectancy.