Water may look the same everywhere, but in reality it can have quite a different effect on the quality of your laundering, depending upon its hardness or softness.
Water has always been the most important commodity in any type or size of laundry. The effect of water and water quality is more critical today than ever before in the performance of cleaning products.
Water, whether from a private well or municipal supply, comes from two general sources: surface water and ground water. Surface waters include lakes, rivers, ponds, and reservoirs. Ground water is obtained from wells. When rain falls, it is nearly pure water, chemically. It is free of dissolved minerals, but it may contain dissolved gases from the air, which make it a weak acid. The rainwater dissolves mineral matter as it flows over and through the ground on its way to rivers, lakes, springs, and the ground water supply.
The dissolved matter may be a wide variety of minerals including calcium, magnesium, and iron compounds. In addition, movement of the water may stir up small particles of insoluble matter (turbidity) and cause a color change in the water. All of these materials carried by water cause problems in laundries.
Laundering problems are often caused by poor water quality and laundering techniques rather than by the equipment or cleaning products used. The best water for laundering is soft and practically free of iron, manganese, and turbidity, with no color. Soft water enables soaps and detergents to clean at maximum efficiency.
Water is expensive in laundry usage. The cost of buying the water and associated sewer charges to get rid of it typically exceeds all washing supplies combined. Based on several surveys, most laundries use between 2.5 and 4.4 gallons of water per pound of fabric. This is important when figuring the size of a water softener for a laundry.
Hardness in laundry water is a problem because the minerals that cause hardness interfere with the cleaning action of soaps and detergents. As a result, larger amounts of soaps and detergents are needed to counteract the minerals, and laundry results are not as good as when there is no hardness present.
Hardness minerals also react with carbonate builders commonly found in non phosphate detergents. The resulting product is a white precipitate, calcium and magnesium carbonate, that makes fabrics stiff and harsh and leaves a film on fabrics which tends to make colors appear faded or streaked with white. No precipitate is formed when the carbonate-built detergents are used in soft water.
The difference in performance in hard and soft water is most dramatic when soap is used. Soap reacts with the calcium in hard water to form sticky curds: hence, there must be more soap than is needed to react with all the calcium in the water before it can start to clean. Consequently, more soap is needed for cleaning in hard water than in soft water. The soap curds formed by the reaction mentioned above are a problem in laundering because they cling to clothes and trap soil on fabrics.
In recent years there has been renewed interest in soap, but because soap is more sensitive to water hardness than detergents, soap should be used only in soft water. Rinse water should be softened as well as wash water to prevent soap curd formation and to eliminate chemical and detergent residue in fabrics.
It is well known that it is more costly to get quality washing in hard water. As a rule of thumb, it takes an additional 1½ pounds of soap per 1,000 gallons for each grain of hardness. For example, if there were 10 grains of hardness in the wash water, an additional 15 pounds of soap would be required for each 1,000 gallons.
Iron causes staining of fabrics. Iron stains are yellow to orange in color. The color cannot be removed by bleaching; in fact, bleaching with chlorine might increase staining. Iron may enter the water as it passes through the earth or it may come from rusting pipes or water heaters. Very small concentrations can cause troublesome staining of fabrics. Iron can be removed by the ion exchange process in varying amounts with a water softener. Thus, when both hardness and iron are present, it may be possible to solve the problem with just one piece of equipment.
The presence of manganese in laundry water is relatively rare, but when it is present, brown stains occur. Contingent upon the amount of manganese, a softener is able to eliminate the staining problem.
Water can be softened automatically by cation exchange (mechanical) water softeners. Water which has been softened by cation exchange still contains dissolved minerals, but there is no calcium or magnesium present. Mechanical water softeners require an initial investment and small operating cost. In many areas, it is possible to rent equipment for a small monthly charge, thus avoiding the initial investment. Long-term savings resulting from reduced use of cleaning supplies and from longer life of fabrics and water-using equipment offset the cost of buying or renting water softening equipment.
Cation exchange water softeners must be regenerated periodically to provide a continuous supply of soft water. The fully automatic regeneration requires no attention from the owner other than keeping the brine tank filled with salt. Rented equipment may be the fully automatic type or may be a tank, which is exchanged periodically by the supplier. Called portable exchange service.
Regeneration of softeners can be done manually or automatically. Automatic regeneration is handled by either a time clock or a sensor control system. With the time clock, the softeners are regenerated at predetermined intervals. With the sensor, the softeners only regenerate when needed, thus saving both salt and water. With sensors, the softeners are fitted with probes that sense the difference between hard and soft water, so that as the softener resin becomes exhausted, the softeners go into regeneration. In effect, it compensates for any water usage or hardness variance. Savings both in salt (up to 47 percent over a time clock softener) and water are the benefits of using a sensor.
Both soaps and synthetic detergents do a better cleaning job in soft water, and in hard water the performance of soap is impaired more that synthetic detergents. Some feel this is a plus for synthetic detergents and have become careless about controlling water hardness. As a result, many laundries have water-softening systems that are either not used or not properly maintained.
Whether washing is done with soap or synthetic detergent, maximum savings of these materials will be realized when the water is zero grains hardness. In earlier days, using untreated hard water could be tolerated by adding more detergent at an overall lower cost than keeping the softener on stream. At today's prices, together with other considerations that now exist the "add-more-detergent" philosophy is no longer a valid approach.
A more careful evaluation my reveal that it would be even less costly to bring a softener on stream and use a good soap. Add to this the fact that a higher quality wash may result, and the idea becomes more attractive. Since the ban on phosphates is becoming more widespread, this is another reason for softened water. The primary purpose of phosphates in detergent is to soften the water. It has been proven that softened water provided excellent laundering with or without phosphates.
Since softened water does a better job of cleaning, it is easier on washables. For example, the life of linens is almost doubled. In one documented study, after new sheets were washed 135 times in hard water, they had to be discarded. In softened water, new sheets withstood 250 washings.
An area of increased importance to all laundries is the rising cost of energy. Water conditioning can conserve energy for the laundry in the following ways:
There are six important benefits in properly conditioning water:
Corrosion (Rust) - The eating away of metal parts. The most noticeable effects of corrosion are leaks, flow stoppage, valve failure, and pitting.
Hardness - Dissolved calcium and magnesium salts in water. Compounds of these two elements cause pipe-scaling problems. They also form a curd with soaps and detergents, reducing their cleaning effectiveness.
Iron - Causes staining in laundered fabrics and on fixtures. Yellow to orange in color.
Manganese - Similar to iron in its tendency to stain. Stains are more severe when chlorine bleaches are used.
pH - A number denoting the alkalinity or acidity of an element such as water. The pH scale is from 0 to 14; Numbers below 7.0 indicate acidity and above 7.0 indicate alkalinity. 7.0 is neutral.
Soft Water - Water containing unobjectionable quantities of calcium and magnesium salts.
Tannin - Complex organic material that usually discolors water similar to iron, but doesn't stain.
Turbidity - Undissolved and suspended material in water, such as finely divided particles of sand.