What is alkali hydrolysis? How can I test for it? Identify it? Prevent it? Resolve it? I know that washload titrations can identify alkali hydro. However, if our titration levels are normal. Can alkali hydrolysis still be affecting our merchandise?
Our white tablecloths have become tender at the corners breaking apart (in one direction) and the breakdown of fibers is visible.
- Brian, GM of O.K. Towel and Uniform Supply, Elizabeth, NJ

Answer: The process of fibers breaking down in fabrics generally describes alkali hydrolysis. Excessively high pH levels, along with high temperatures, causes the damage. The fibers are pitted and noticeably weak, commonly referred to as tensile strength loss. Cotton is generally resistant to high levels of alkali, but polyester blends can be easily damaged from the combination of high temperatures and pH levels in excess of 11.5. Quats, commonly used in chemical fabric softeners, will greatly increase alkali hydrolysis when processing polyester material. Most manufacturers recommend not using Quats on polyester fabrics.
Choosing the proper alkali levels for the fabric type is important. It is also necessary to monitor the pH in the wash bath, maintain temperatures to 160 degrees or less, and not overload the wash wheel. The proper number of rinses and correct stepping down of temperature in each bath is important, and there should be less than 50 PPM of alkalinity in the last rinse. The final step where sour is used to remove residual alkalinity should be adequate in time or step to adjust the desired pH evenly across the material.
Since the fabric content isn’t identified, but was mentioned to be white linen, it should not be overlooked that bleaching can cause damage. Proper methods of bleaching and rinsing, and the use of an anti-chlor can be important to linen life.

Rich Fitzmorris, Vice President, Laundry Division, Sunburst Chemicals.

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I work in a 400-room business resort hotel in southern Malaysia. The bed linen has a bad odor when it goes to the floors, but they do not smell before they leave the laundry department. What causes this? Can storing warm linen in an air-conditioned room or pantry cause the linens to smell?
-Seth, laundry manager, Eden, Malaysia

Answer: Linen that generates an odor when stored is often caused by bacteria growth. Linens that have been ironed but are not completely dry before being stored create an ideal environment for bacteria growth.

Mildew may not show up on the linens as visible spots, but without proper chemistry it is not likely to go away. In addition, the covers and pads on the ironer can harbor bacteria if temperatures on the covers are not high enough to kill them.

Rich Fitzmorris, Vice President, Laundry Division, Sunburst Chemicals.

What is the concentration of sodium chlorite in bleach purchased at a grocery store?
-Vince, TKH Sales, Merrivile, IN

Answer: Household bleach is generally 5.25% sodium hypochlorite. There can be differences in stability and pH of these products.

Rich Fitzmorris, Vice President, Laundry Division, Sunburst Chemicals.

What is the best method of removing makeup from bath, hand and pool towels? --Doug

Answer: Makeup stains are a problem in any general wash formula because most makeup is not water-soluble. The percentage of makeup stains is too small to warrant an aggressive formula that will reduce tensile strength and lead to increased costs in chemicals and utilities.
There are two ways to deal with makeup stains. The first is to institute a good post-spotting program. Items are set-aside after the initial washing to be spotted and washed on the general formula for that material. The second method is to set stained linens aside until there is ¾ of a load, which can be stain treated with the proper chemistry and formula.

Rich Fitzmorris, Vice President, Laundry Division, Sunburst Chemicals.