Some unknown factor has increased the hardness of the water entering my laundry. How can we combat this change so we can produce high-quality linen without jeopardizing production efficiency? What options are available to me to address this hard-water problem?TECHNICAL SUPPORT: Jim Mitchell, principal technical support specialist for Ecolab, Eagan, Minn., is a 25-year company veteran. He's currently its OPL lead in providing technical support to field associates. He edits Ecolab’s Institutional Technical Digest, a monthly publication reaching 2,800 employees.
All laundry operations should conduct monthly water-hardness tests. You should never assume that your water conditions won’t change. Whether your water is supplied from a municipal system or a private well, changes in water quality can happen overnight. Monthly testing can be an indicator of a hardness issue before it interferes with quality.
An increase in water hardness can create the following scenarios:
- Residual hardness (calcium/ magnesium) tied up in fabrics can lead to graying. If the residual hardness also includes dissolved minerals such as iron, manganese, etc., fabrics can also turn shades of orange, yellow or brown.
- Residual hardness can create a rough feeling in linen, particularly terry items.
- An increase in hardness can lead to a higher reject rate from poor soil removal.
- Elevated hardness levels generally require a change in laundry products and/or product dilution rates, which can create an increase in chemical costs.
Changes in water quality can be a naturally occurring problem. Drought conditions, as well as conditions of heavy rain, can create changes in water quality in a relatively short period of time.
In some areas of the country, these changes are seasonal due to spring snow melt and/or annual summer drought conditions. These fluctuating climate conditions can rapidly alter the quality of ground water as well as the quality of surface sources such as reservoirs. As these water tables rise and fall in response to climatic changes, water quality can change accordingly.
These changes can impact municipal water supplies as well as private wells. If your water is from a municipal source, and if a change is noted in your water quality, contact your local water works department to verify the issue.
Water quality can also change when the demand for water forces utilities to secure water from other sources to meet demand. Drawing water from an outside source can create an immediate change in quality, as the quality of water from one geographic area to another are rarely equal.
And, of course, facilities that soften water in-house will experience a dramatic change in water quality if their water-softening system quits functioning properly.
Water-hardness tests can be easily performed by your laundry chemical supply company to verify your softener is operating properly. Some high-volume softening systems are designed to soften all incoming water to a facility. Most softening systems, however, are installed to only soften the hot-water supply. When conducting a hardness test, be sure to test both the hot- and cold-water supplies. Water-hardness test kits are also available at businesses that sell and maintain water-softening systems.What can I do?
There’s very little, or nothing you can do about altering the quality of the water prior to it entering your building of operation. However, once inside your building, there are a number of options available.
First, prepare yourself for a future water issue. Bag some linen to be used as a standard. Changes in linen results due to an increase in water hardness can be so gradual at times that the naked eye can have a hard time noticing them. By the time a change is finally noticed, permanent discoloration to the fabric may have occurred.
It’s a good practice to keep a number of linen standard samples kept somewhere in storage. The samples you save should be of a high quality in terms of whiteness, softness and soil removal. Periodically, compare them to the quality of linen recently washed, especially during times when you’ve detected a change in water quality. Any subtle changes in fabric quality, especially graying, should be reported to your chemical supplier representative. Changes in product dilution rates and/or product mix may have to be made to compensate.
In the case of a malfunctioning water softener, get it repaired as soon as possible! Your laundry chemical supply company should have set your chemical dilution rates for softer water conditions. When water hardness conditions skyrocket due to a malfunctioning softener, linen results will suffer if chemical dilution rates aren’t adjusted accordingly. Failure to invest the money required to fix a malfunctioning softener will cost your operation much more money in linen replacement costs in the long run.Can I filter my water hardness out of the water supply?
No. Even the best carbon water filters on the market today can’t filter most dissolved minerals out of the water. These minerals are too fine to be trapped in such filters. In most cases, these fine particles can only be effectively trapped in a membrane-type filter system (reverse osmosis). These systems will filter virtually all impurities out of a water supply. However, RO systems can be expensive, and RO water can also be corrosive.Should my laundry product chemistry be changed?
Some minor changes in water hardness can have little or no effect on your linen results. Most laundry products/chemicals (detergents, conditioners, sours, etc.) have water hardness tolerance ranges. Some are designed for soft to medium water conditions only. A subtle change in hardness may not impact their performance. However, if the hardness change is beyond their effective range, results issues will eventually surface.
A built detergent that performed well in lower hardness may now require the aid of a conditioner to boost its performance. If a conditioner is already in the operation, the volume/dosage of this product may have to be increased to boost the detergent’s performance.
OK, that takes care of the detergent cycle. But what about all of the remaining cycles in the wash formula?
Water hardness can definitely be redeposited into the fabrics long after the suds bath if it’s not chemically controlled. This is where a good souring (acid) agent is invaluable.
A generic phosphoric/citric acid souring agent is capable of handling water conditions from soft to medium/hard. However, these acids may not perform well in elevated hardness levels, especially those that also include moderate to high levels of iron and/or manganese. These conditions may require the assistance of a stronger acid, such as a hydrofluosilicic. Care should be taken when using stronger acids, however, as overuse of these products can lead to linen damage.Do my laundry wash machine formulas need to be changed?
Not necessarily, unless there’s a dramatic change in water hardness. Soil removal in soft-water conditions can usually be accomplished with minimal chemical dosages, and short to moderate wash formulas. Hard-water conditions can require longer contact time with chemicals for soil removal, water conditioning and the prevention of hardness redeposition in the final rinses. Thus, the detergent, bleach and final rinse (sour/soft) cycles have to be extended for longer chemical contact time.