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Wash Chemistry Basics (Part 1)

Essential wash formula elements, chemicals

CHICAGO — The wash formula.

It’s essential for laundry and linen services to use the correct wash formula to process goods.

“Wash formulas are tailored to each classification depending on soil type, color, soil degree and fiber content,” says Amanda Steffen, marketing director for Ecolab, which provides water, hygiene and energy technologies and services.

A key component to a wash formula is the chemistry.

“The effectiveness of chemistry is equally important as the time, temperature and mechanical action of the entire wash process,” Steffen says. “It’s a balance of these four factors.”

That means laundry operations need to make sure they are using the right chemicals, and sometimes that means going back to the basics of washroom chemistry to make sure the right chemicals are being used.

ESSENTIAL FORMULA ELEMENTS

As Steffen notes, the basic elements considered in designing an effective and efficient wash chemistry formula include soil types and levels, fabric composition, wash temperatures and the type of wash equipment.

Steve Tinker, senior vice president-research and development, marketing for Gurtler Industries Inc., a commercial laundry products supplier, says that production needs, which helps determine maximum wash times, are also considered.

“Knowing all these factors allow the chemical technician to select the right combination of washing chemistry, detergents, builders, water and soil conditioners, bleaches, and specialty products,” he says. 

“Quality standards are a critical component of the overall formulation. The final equation includes the overall cost impact, which includes chemical costs, water and sewer costs, energy costs, productivity inputs, and even textile life analysis.” 

Wash chemistry is guided by the pie chart giving equal weight to time, temperature, mechanical action and chemical, says Scott Pariser, president of Pariser Industries Inc., which manufactures specialty cleaning chemicals for commercial, industrial and institutional end users.

“As each of the pieces of the pie are changed, other parts of the pie must be modified in order to make sure the overall ‘cleaning’ process is the best it can be,” points out Doug Story, president of sales and marketing for UNX, a company that provides chemical detergents and specialties to key consumer industries. 

“Soil loading and equipment type will affect how the pieces of the pie are developed but all components of the pie must exist in order for proper cleaning in a laundry process to occur. For example, if an operator wants to speed up the formula, reducing time, there has to be an increase in one or more parts of the pie—increase chemical usage, increase temperature would be one strategy.”

Pariser agrees that product lineups and respective wash formulas are best conceived when appropriate consideration is given to soil classifications, linen specifications, operating conditions (i.e., water hardness and quality, hot water temperatures, etc.), and production requirements.

Bill Mitchell, vice president of customer care and national sales for Norchem Corp., a clean-technology engineering firm, says a laundry washroom has an effect on several areas of the plant’s overall operation. 

“Wash quality is, of course, a top priority, as that is what their customers expect and are paying for,” he says. “Beyond finished quality, a laundry should consider the impact of the wash process on the longevity of their textiles, the efficiency of the wash process in producing more pounds per hour, the cost of utilities needed and the effluent water discharged to the local treatment works.” 

Mitchell points out that wash chemicals can have an effect on all of these areas, and chemical suppliers should be able to work with the laundries to ensure all opportunities of efficiency and compliance are recognized and accounted for in an overall chemical supply program.

ESSENTIAL CHEMICALS

Kevin Minissian, president of Norchem, says, “The foundation for any successful wash program starts with the following: Good soft water, effective detergent, and stain removers, such as chlorine bleach and hydrogen peroxide.”

Pariser shares that, generally speaking, an alkaline builder, a surfactant, a bleaching agent (whether it is chlorine or oxygen bleach in nature), a neutralizing sour and a softening agent are the basic components of a chemical menu.   

“All plants will use alkali, surfactants, chelating agents, oxidizing agents, sours and fabric softeners,” adds Story.

Tinker shares the following details on each of the essential chemical elements used in a laundry:

Alkalis: Break-down and neutralize soils and condition natural textiles to help release soils.

Detergents: The most important element in the wash formula. Emulsify, lift away and suspend oily and greasy soils, and are especially effective on synthetic fibers.  

Detergents are designed to work at various temperature ranges depending on the needs of the laundry. They are also engineered to have a controlled level of foaming, which is also temperature dependent. Excessive foam can be a detriment, as it reduces the mechanical action of the washer.  

All these various considerations—textiles, soils and temperatures—are taken into consideration when selecting a detergent product. 

Conditioners: Help suspend soils and isolate water hardness ions that can interfere in soil removal. Phosphate and non-phosphate conditioners are available, depending on local requirements.

Bleaches: Chlorine, oxygen and peracetic acid are the basic choices for bleaches. Each has its advantages and issues. Selecting the right bleach is an important part of designing the right wash process for the laundry.

Specialty Products: Pre-washes, solvents, softeners, anti-chlors and sanitizers are all optional products.

Neutralizers (Sours): Used in the final rinse to reduce the pH of the textiles to about 5-6.5, which is the pH of human skin. This not only helps reduce any skin irritation that may occur from detergent residues, but it also aids in ironing. 

Beyond the essential elements, there are several additional options laundry operators can use to boost cleaning.

“Depending upon plant conditions, linen type and soil classifications, a specific degreasing adjunct, a water softening conditioner, an anti-chlor (chlorine neutralizer), and a bacteriostatic agent may also be employed to enhance linen appearance, longevity and hygiene,” Pariser says.

Minissian says alkaline builders can be used to boost up alkalinity in the wash for better and more aggressive soil dispersing and cleaning effectiveness.

Healthcare laundries can leverage an EPA-registered laundry disinfectant oxidizer with proven kill claims against healthcare-related microorganisms of concern that help contribute to the most common healthcare-associated infections (HAIs), according to Steffen.

“Water softening is an important part of a laundry operation,” Tinker says. “If the water is not soft—zero grains per gallon hardness—the laundry will have to use more chemistry and additives to ‘condition’ the water.

“Solvent-based detergents can be added in a prewash step to help remove oily/greasy soils form heavily soiled items.”

And Story shares that there are new developments in technology based on enzymes and other bio-active agents that have the capability of enhancing quality in lower temperature and reduced chemical intensity laundering programs.

Check back Thursday for the conclusion on common mistakes.