This article is reprinted with permission from the Bummis retailer newsletter
At this year’s Real Diaper Industry Association Annual Meeting, there was a fantastic presentation on laundry science. It was given by Steven J. Tinker, who is the Vice President of Research & Development at Gurtler Industries, Inc. and has over 35 years of experience in the detergent industry. He is also the president of the American Reusable Textile Association and the Vice-Chair of the Advisory Committee of the Healthcare Laundry Accreditation Council.
The Science Behind the Clean Diapers
The main point of Mr. Tinker’s presentation was that water is 99+% of what we wash with, therefore the quality of your water is critical for the best results. He strongly encouraged all who have even medium-hard water to invest in a water softening device. Costs are quickly recovered by savings on detergent and by reducing wear and tear on appliances, fabric and plumbing. Water hardness is a measure of the calcium and magnesium carbonate present in your water.
Other factors in water that can affect washing include total dissolved solids, chlorine, iron (yellowing), alkalinity (problems rinsing, harsh fabric), organic matter, etc. So, in other words, water quality is crucial to washing success.
Four Main Factors
The other main factors in washing success are chemical action (detergent), mechanical action (swooshing), water temperature, and time (how long the wash cycle lasts). These four components need to fill the pie chart.
Chemical action is achieved by the detergent you add to the water.
Mechanical action is achieved by the movement of the fabrics against one another inside the washing machine. You can slightly under-load your machine, but not by much, or there will not be enough fabric to rub against itself. Think of washboards in the river and how pioneers rubbed the fabric against the boards to create the mechanical action that drew the soil out of the fabric. It is also important to note that if you over-load your washing machine, you will not get enough rubbing action either, as there is no room for the diapers to move!
Temperature: for every 10 degree drop in temperature below 110F, there is a 50% reduction in the chemical reaction – so washing in warm to hot water is best.
Time is crucial! If fabric is not exposed to detergent and mechanical action long enough, water will not penetrate fabric and soils will not be released.
What is a surfactant?
This is the active cleaning agent in most detergent formulations. Surfactants change the chemical and physical relationship between water and the surface to be cleaned.
Some surfactants are naturally occurring and some are synthetic. Surfactants loosen and suspend soil and enhance the wetting property of water. Soaps are a type of surfactant and natural soaps such as soap nuts, castile soap, Ivory Soap, etc. can work well under ideal water conditions. Unfortunately many of us have less than ideal water conditions and in this case the minerals in our wtaer can bind to the soap and create a scum on the surface of the water. This scum can cause repellency and leaking issues as well as causing diapers to look dingy.
What about enzymes?
A detergent may also contain enzymes. There are three basic enzymes: protease (which works on proteins), amylase (which works on starches), and lipase (which works on fats). Mr. Tinker did not feel that protease or amylase pose any problems for skin or fabric. Because fat is stored in the skin, lipase can potentially cause a skin reaction in those who are particularly sensitive. In actual fact however, most people can use enzymes with no problems at all, and he did note that they are effective at removing odours!
We encourage the use of oxygenated bleach instead of chlorine bleach for environmental and health reasons, and also because chlorine bleach is extremely destructive to fabrics and laminations, etc. If chlorine bleach is ever used in a home wash – for example to deal with a particularly tough yeast infection, it is important to make sure that all urine is completely rinsed out before using it, because urine + chlorine = ammonia smell from chloramines!
1) Dilution. Each time you change out the water (pre-rinse, wash, rinse…), you dilute the amount of bio-burden in the wash and flush it away.
2) Heat. Temperatures of 140+F (60+C) (hot water wash) deactivate common bio-organisms.
3) pH. This is applicable mainly in commerical laundries
4) Oxidation. Chlorine or oxygen bleaches.
5) Heat from drying in the dryer on a heat setting.