DOING THE PRODUCT RESEARCH
So many brands, but only a handful of materials to know
To say that selecting a deicer to carry and recommend can be confusing is an understatement. There are so many carefully worded claims. It’s easy to conclude they’re all about the same (and believe your customers feel the same).
But the fact is that there are big differences between ice melters. These differences impact their true cost and, more important, your customer’s ability to get walks and drives clear and safe fast…under all conditions…with minimal side effects. Let’s review these differences to see why PELADOW calcium chloride pellets clearly do deserve the leadership position they have enjoyed for many years.
First, the basics on how deicers work
The two most widely used deicers occur naturally: calcium chloride and sodium chloride (rock salt). Potassium chloride and magnesium chloride also occur naturally and are used to some extent. Urea is a manufactured material widely used as a fertilizer and sometimes as a deicer. These few materials and blends of these materials account for nearly all of the deicers used today.
Unfortunately, how deicers work isn’t that interesting, but it’s important to understand if we’re going to set the record straight. So please stick with us.
Deicers are incapable of melting snow or ice in their solid form. They must form liquid brine. This brine lowers the freezing point of water and effectively dissolves (melts) ice and snow on contact until it becomes diluted to a concentration where its freezing point is raised near water’s.
To be effective, deicers must penetrate snow and ice until they reach the pavement. Then the brines can fan out under the ice to break its bond with the pavement. Once loose, ice and snow are easily removed. That is, if the deicer doesn’t “run out of gas” first.
Now, even though similar mechanics are involved, there are dramatic differences in how each deicer works under actual conditions at the application rates recommended by the manufacturers. And this is where it gets interesting.
PELADOW works faster at every temperature
Let’s talk about speed first. Big differences. Here’s why:
A deicer’s speed of action depends on how fast it becomes brine. This depends on how quickly it takes up moisture. And this depends on the temperature, the freezing point of the brine created, and the nature of the material. Stay with us. It really isn’t that complicated.
Sodium chloride, potassium chloride, and urea must come in direct contact with moisture before they can dissolve into an effective deicing brine. That takes time.
By contrast, calcium chloride and magnesium chloride readily attract moisture from the atmosphere to form brine very quickly. Calcium chloride attracts more moisture under a wider range of conditions than magnesium chloride.
This moisture-attracting ability separates calcium chloride and magnesium chloride from the others. But there’s another difference that narrows the field even further.
Calcium chloride and magnesium chloride actually generate heat as they go into solution. They create what is called an exothermic reaction. For example, a pound of calcium chloride generates 290 BTUs as it dissolves – enough heat to raise the temperature of one gallon of water by 35°F.
Other deicers have just the opposite effect. They create an endothermic reaction. Rock salt, for example, must draw 39 BTUs to go into solution. Potassium chloride requires even more heat energy (170 BTUs). Urea requires 106 BTUs. These materials absorb enough heat to lower the temperature of that same gallon of water by 5°F, 20°F, and 13°F, respectively. Under practical conditions, when temperatures drop much below freezing, the rate of heat pickup from the ice and snow slows to a point where these materials have a very hard time creating brine. And no brine means no action.
Here’s another important factor: the freezing points of deicer brines. Every deicer has what is called a eutectic temperature. This is the lowest temperature at which a deicer brine can dissolve ice. The eutectic temperature only applies to a specific concentration of a deicer in water. And none of the materials are capable of staying at this specific concentration for long because they are constantly melting more ice and becoming more diluted so their freezing point changes.
Obviously, eutectic temperatures have little bearing on real-life deicing conditions, but it is true that the lower the eutectic temperature, the more quickly the deicer can create brine … and the faster it can start getting the job done. Also, the lower the eutectic temperature, the lower the practical temperature limit of the deicer. This is generally accepted as the lowest temperature at which sufficient deicing action is evident within a reasonable period of time.
The table below compares the theoretical and practical low temperature limits of the common deicing materials. Notice that only calcium chloride pellets remain practically effective to -25°F.
Also note that when it comes to blends, effectiveness is controlled by the material with the lowest eutectic temperature.
|Comparing Melting Temperatures|
|Material||Eutectic Temperature||Lowest Practical Temperature|
This table shows the difference between the theoretical and practical temperature limits of common deicers. Be wary of claims made on packages based on theoretical limits. While technically correct, they are unrelated to the deicer’s performance in actual use.
PELADOW melts more
Next let’s look at the amount of deicer needed to get the job done. The best way to compare is to look at the volume of ice these common materials are able to melt within normal temperature conditions over a reasonable time period.
Test results show that Peladow melts more so your customers can use less. How much less? Consider this: the application rates for PELADOW are recommended at just 2-4 ounces per square yard while the others are typically recommended at 6-8 ounces per square yard. That’s one-half or less! Granted, this may first sound unattractive to you as a distributor. But remember PELADOW commands a premium price for this superior performance. Also, consider most customers use PELADOW at lower temperatures than others. Total sales volume is typically equal or higher with PELADOW.
PELADOW works longer
Not only can customers start with less PELADOW calcium chloride pellets than other ice melters, they can apply less frequently. That’s because PELADOW works longer. And that’s because it so fiercely resists evaporation as it constantly tries to stay in its natural liquid state… and because the freezing point of even very dilute solutions of PELADOW is low. Even when diluted to a 20% concentration, it keeps working down to -4°F.
PELADOW won’t leave a powdery residue
A big drawback with deicers that are naturally solids … rock salt, potassium chloride, and urea … is that they quickly return to solid form if tracked into buildings. Calcium chloride, on the other hand, will not leave a powdery residue. Besides saving your customers time outside, they save time on housekeeping chores inside too.
PELADOW is easiest on plants
All common deicers … even those used as fertilizers … have the potential to harm vegetation. But ongoing research at the Iowa State University Department of Horticulture has documented that calcium chloride poses less threat than others … even when all are applied at the same rate. Now, add the fact that customers can use less PELADOW to get the job done, and you’ve got another reason why PELADOW is preferred by so many.
PELADOW is easiest on concrete
There’s a common misconception that deicers chemically attack concrete. They don’t. The threat to concrete is the pressure created when water in concrete freezes. It’s true that common deicers can hurt this situation because they affect the freezing point of water. Depending on the weather and the freeze point of brine, the number of freeze/thaw cycles can be increased. Nonetheless, people want to know which deicer poses the least threat of damage to concrete. And that’s PELADOW, as shown by research conducted using ASTM C-672-76, “Test for Scaling Resistance of Concrete Surfaces Exposed to Chemical Deicers,” modified by reducing freeze/thaw cycle time from 24 hours to 8 hours per cycle. This test involved diluting deicers to various concentrations and placing them ½” deep on air-entrained concrete slabs which are alternately frozen and thawed. Samples were exposed to 500 cycles, then the surface of each sample was examined and numerically rated as to the amount of scaling, using the following rating system:
0 = No scaling
1 = Very slight scaling
2 = Slight to moderate scaling
3 = Moderate scaling
4 = Moderate to severe scaling
5 = Severe scaling
As shown, results at 2%, 4%, and 8% deicer concentration found samples exposed to calcium
Chloride scaled less than others… and less than samples exposed to plain water.
Scale Rating After 500 Freeze/Thaw Cycles
The point is that deicers don’t attack concrete. In fact, they are minimally harmful to good quality concrete under the worst conditions. Nonetheless, they also found that calcium chloride was even less harmful than the rest.
The extra advantage with pellets
One last thing. The shape of a deicer makes a big difference. Round pellets have a distinct advantage because each pellet contacts a very small area of ice and spends its time boring vertically downward. Flakes and chips are flatter and contact a larger surface area so they tend to work as hard horizontally as vertically. Since the whole idea is to penetrate ice and snow and break the bond with the pavement, it’s better to have a pellet-shaped material that penetrates downward faster.
Conclusion: Customers want the best and know PELADOW is proven the best
When all the facts are in it’s easy to see why PELADOW calcium chloride pellets lead the way in premium ice melters. It’s simply been proven superior by every measure customers consider important.
Published by the Dow Chemical Company