‘White challenge’ in fabric care

The common challenges to efficient laundry are drying & finishing (which could be reduced by using high efficiency washer extractor with the high G-Force) and cost of essential resources like water and electricity; but one major operational challenge is in keeping the linen white. Maintaining whiteness of linen depends on several factors, including the following:

Water

Quality: a. The water hardness should be below 50 PPM.

b. The dissolved iron content should be less than 0.2 PPM

Quantity: There should be enough of mechanical action in the washing machine. Quantity of water used in wash cycle and rinse cycle plays an important part. For example, excess water during the wash cycle would result in less mechanical action and soil removal. At the same time, less water during the rinse cycle would result in less soil removal and soil re-deposition. Also the number of rinses could be fixed based on the pH of the discharged water.

Mechanical Action

The contours and the speed of the drum should ensure maximum mechanical agitation. Again the mechanical action is not the same for all kinds of linen. For example, delicate linen should be washed at lower drum speed. All garments running out colour (excess colours) should be washed in large quantities of water, so that the colour does not run on white garments.

Temperature

Soil removal used to be better at a high temperature with the old type of detergent, but the new age industrial detergents are efficient even at low temperatures. The present industrial detergents available have the right mixture of chemicals needed for washing. Generally, a good detergent will have an ionic wetting agent & non-ionic wetting agent, surfactants, chelating compound, anti re-depositing agents and optical brighter. Laundries are looking for ways to cut energy costs and help environment. Detergent manufacturers have an eye on these trends and are developing eco-friendly and energy efficient products. Most of the detergents are alkaline in nature; hence a neutralizer is added in the last rinse to bring down the pH. Neutralizer also helps in reducing the water used for rinsing.

Naked eye is not enough to check the whiteness of the fabric. The whiteness gets impacted by usage; hence it has to be measured regularly so that the standard could be maintained. Reflect-o-metre is used to check the whiteness of the fabric. This is a qualitative measure of the brightness.

Optical Brightener

Optical brighteners get disintegrated over a period of time due to heat and chemicals. Hence, addition of optical brighteners once a while increases the brightness of the fabric.

Tips

• Segregate stains and soils before they are put in the washing machine. Pre-treat with liquid detergent or stain remover before washing.
• Muddy fabrics like outdoor towels to be flushed (pre-washed).
• The presence of dissolved heavy metals in the water should be neutralized
• Fill the washing machine only up to 85% with linen
• Do not iron the linen/garment if the stain is not fully removed
• Treat the stains immediately before it penetrates the thread
• Use phosphate free detergents

Qualified managers and trained manpower are in short supply today. With increasing awareness among the general public, the scene will change and the young textile and chemical engineers with better solutions will find fabric care as a lucrative career.