Wash-formula selection could be compared to building a house of cards. If you carefully consider how your next card will fit with the rest before putting it in place, your house has a better chance of remaining balanced.
But rush your next move or place your next card in the wrong spot and the resulting chain reaction will almost certainly bring the whole thing crashing down.
When laundering, that kind of misstep can cause poor soil removal or even textile damage. Formula selection is affected by several factors, any one of which can impact the final product for better or worse.
Failing to understand and account for the interdependency of these soil-removal factors could render a wash formula ineffective.
THE FOUR BASICS, PLUS...
Processing time, water temperature, chemical action and the washer’s mechanical action are generally accepted as the main variables in achieving good wash results, but there are more to consider, American Laundry News learned while polling several washroom chemical vendors on the topic.
Jim Mitchell, principal technical support specialist for Ecolab, says his company also factors in “procedures.” Employees’ improper presorting, formula choice, dryer settings and stain treatment can all lead to what he calls “result issues” over time.
Ed Offshack, associate director of global technology development for P&G Professional, agrees. “If people don’t properly load the machine, or they put in sheets and pick a towel formula, they can really defeat all the other attributes.”
He also suggests that water quality – is it hard? – can be a factor.
Gurtler Industries’ Steve Tinker, director of research and development, says the type of wash equipment, fabric, and the degree and type of soils are also important to formula selection. “Many outside factors impact the process, making adjustments in the formulation imperative. … Although a specific laundry may not be able to adjust these factors, they influence the design of a wash formula.”
The impact of each of the basic factors “depends on where you’re at in the matrix of these four variables,” says Tom Storm, vice president of technical development for Washing Systems Inc. (WSI).
“Soil removal as a function of time tends to flatten out as time increases,” he says. “However, in most cases, temperature probably has the greatest effect. This is because for every 10 C (18 F) increase in temperature, the rate of a chemical reaction doubles. Soil removal is not as strongly affected by an increase in the other factors.
“However, temperature is a two-edged sword. Increasing temperature increases soil removal, but it also increases soil redeposition, color loss, fabric damage and can deactivate enzymes.”
“Everything works better if you give it a longer wash cycle,” submits Noramtech President Michael Oberlander, “assuming you have antideposition agents in there.”
TRIAL AND ERROR?
Is the key to selecting an effective wash formula mostly learning through trial and error, or are there enough “standard” formulas in the marketplace?
Gurtler has developed a standard wash formula guide for its service specialists, Tinker says, with more than 60 different recommended wash formulas depending on machine type, textile type and soil classification.
“But, these standard formulas are just a starting point for our specialists,” he says. “Designing the wash formulas for a laundry is as much an art as it is a science. With so many variables affecting cost and quality, our specialists must rely on experience and on-site trials to make sure that the best, most efficient formulas are implemented.”
“Because soil classifications in most institutional laundry operations are quite generic, most preprogrammed formulas available on the market will suffice,” Mitchell says.
“Industrial operations are not as ‘generic’ as institutional,” he adds. “Soil classifications and soil loads vary widely. Industrial-grade greases and oils, transmission fluids, tar, blood and animal fats from food processing will all create ‘special’ chemical blends as well as formulas.”
“Chemical suppliers will develop standard formulas for each type of chemistry used,” says Storm. “These standard formulas will normally specify a chemical range to account for varying soil levels, but the formula steps, times and temperatures will be set for a specific classification.
“The standard formulas developed will cover 95% of the classifications processed. There will always be a need for some special formula development for those unusual classifications, but those will be small in number.”
Oberlander says his company’s product that washes and bleaches in one operation can remove a lot of guesswork, depending on the soil classification. “Two ounces at 125 degrees, one cycle, and you’re done,” he says.
P&G has developed fairly standard wash programs that work well with its chemistry, Offshack says, but the company has found that preprogrammed washers “don’t work well with the neutral-pH program that we have.”
DO YOU TAKE A SHORTCUT?
“It may save some time, but it can only lead to major problems,” Tinker warns of the practice known in the industry as speed washing.
“Skipping a bleach cycle or a rinse or two can cause a myriad of problems down the line. Soil that is loosened in the wash cycle must be thoroughly rinsed away along with the detergent and alkali. If the rinsing steps are eliminated, soil can redeposit on the fabric. And then the drying process can bake that soil into the fibers, making future removal even more difficult.”
Also, if residual alkalinity and detergent are not completely rinsed out, the garments or linens can cause skin irritation to the users, Tinker says.
“If the wash formula has been properly designed, there will be a negative consequence of taking such an action,” Storm advises. “It may not affect soil removal, but it could produce rolling on the ironers, yellowing upon drying, fabric damage by chlorine carryover, garment irritation, improper starching, etc.”
Boosting washroom productivity can actually create a workflow bottleneck in the drying or finishing area, he adds, so that needs to be taken into account.
Mitchell says some preprogrammed and self-programmed formulas are “overkill” and can usually be shortened without compromising results. Some standard formulas can be shortened under ideal water conditions, temperatures, light soil loads and an optimum blend of chemicals. Shortening “marginal” formulas usually creates issues.
Oberlander says an operator processing a light soil load could possibly cut a rinse step, saving 2-3 minutes during that cycle.
There are “all kinds of step-skipping that go on outside the machine,” according to Offshack.
“Pretreating could be hugely beneficial,” he says. “If you spend more time pretreating, you’ll save time on the back end of the laundry. You’ll have less rework, less rewash and less lost linen.”
Tinker says if a laundry needs to speed up the turnaround time for specific items, it’s best to work with its chemical supplier to develop shorter wash formulas.
How has washroom technology influenced a launderer’s ability to choose and program formulas?
“Download capability among washers allows easier and more mistake-free formulas,” Storm says. “More precise control overall allows wash formulas that are more water-, energy- and chemical-efficient because less buffer is needed to ensure a consistent, high wash quality.”
“The more flexibility in programming ability, the better results we can provide,” says Offshack.
SOME FINAL TIPS
“I think it is extremely important to take formula selection out of the hands of washroom personnel,” Storm says. “Make his only task the proper loading of the washer and initiate the proper formula designated by others.
“The soil room should determine the classification and hence the proper wash formula, since they have sorted the fabrics. All slings or carts should be weighed; consequently, the formula number should be shown on the weigh ticket. This way, the wash room doesn’t have to guess the classification.
“Also, the chemical rep should provide proper training of washroom personnel.”