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Encapsulation Chemistries

Understanding Encapsulation Chemistries
By Mark Warner

There has been a lot of discussion lately regarding encapsulation chemistry. Most of it revolves around two critical issues. One, are all encapsulation systems the same or are they different and if so, how different?  Two, can low moisture cleaning actually clean well enough to be considered for use for restorative cleaning?

First, regarding the discussion of the different types of encapsulation chemistry, perhaps the place to start is to review the evolution of carpet care chemistry itself. The first chemistries used on early carpets were merely soaps, not very different from what you might have used to wash your face or hair. Because of the absorption of solution into the fiber, there was always a case of chemical residue. Why else would the industry have spent the last 50 years trying to improve cleaning efficacy and reduce re-soiling by reducing residues?

In the early days, carpet-cleaning chemicals were known to leave residues and re-soil quickly. We all remember hearing tales of concern about holding off as long as possible before having new carpet cleaned in order to avoid the occurrence of re-soiling. In early research, it was found that natural fibers (common in early carpets) had crags and grooves that would catch and hold soil.

The next chemical evolution was to add a compound known as Ludox, a wax-like substance thought to fill the grooves and crags to prevent soil from being caught. It was an improvement; however it certainly did not solve the re-soiling problem. In fact, it brought on a host of other problems related to the dirty slurry that was created during the cleaning process and ultimately caught in the drying process. It caused the carpets to lose their ability to refract light properly and they would tend to “ugly out” after repeated cleanings.

Next, we went through the phase of detergent encapsulation. This was an attempt to enhance the rinsability of the cleaning chemical by increasing its soil load capability and assisting in its ability to be flushed out of the carpet. As a point of fact, many of these early cleaners were not much different than diluted Fantastic, containing butyl as their active solvent. This was a great improvement over the old soaps and Ludox additives, and it did mark the start of reducing re-soiling, but it didn’t eliminate the problem of re-soiling.

In the mid-eighties, chemists again sought to improve the situation of re-soiling. The problem revolved around the solvents and surfactants in use at the time. These early solvents and surfactants were liquids in their raw state, and as a result, did not want to fully dry down beyond a gelatin or tacky residue. The thought process at the time was to add a component that would force the chemical to dry down to a hard crystalline material. It was thought that acrylic co-polymers (similar to floor finish) could be added, causing the residues to dry to a hard shell around the fiber and the soil. This hard shell would fracture under foot traffic and the action of the beater bar of a vacuum cleaner, breaking away from the fiber and falling toward the backing where it could be vacuumed away at a later date. The biggest challenge of this chemistry was marketing the idea of adding a “floor finish” ingredient to a carpet cleaner. In the end, terms like “acrylic copolymer embrittlement agents” and “crystallizing detergents” were used to describe this chemistry. The concept was very sellable and became very popular, ultimately receiving praise and accolades like “true encapsulation cleaning.”

There were some downsides, however.  A dirty slurry was created during the cleaning process and some of this residue was left behind in the fiber. The problem was that it was no longer a clear, clean acrylic-laced detergent, but an amber brown acrylic crystal created from mixing with soil during the cleaning process. The obvious danger was that some of the acrylic “shell” was left on the fiber where it hadn’t fractured and fallen away in places like open dye sites or abraded areas of the fiber.  The bigger problem became trying to “strip out” the residual acrylics without using “strippers” which would be deleterious to the carpet. Carpets would ultimately “ugly out” over time because the acrylic residues interfered with the way the carpet fiber refracted light. The problem of re-soiling was improved, but not eliminated.

In the late nineties, fluorocarbon chemistry was introduced to carpet cleaning chemicals, often referred to “second generation encapsulation chemistry.” The concept was to leave a Teflon-like substance behind on the fiber, causing dirt and soil to slide off the fiber like a fried egg slides off a Teflon frying pan. The concept had great promise but again had some pitfalls. Also, the government had some concerns surrounding the long-term health effects of fluorocarbons. That debate still rages. But on a more relevant note, most of the available fluorocarbon additives were found to be hygroscopic meaning that they attracted moisture from the atmosphere. We have all witnessed this effect when watching ice-melt work in sub-freezing temperatures.  

Another common experience is feeling the surface of a Teflon pan after it has been cleaned, dried and stored for days in a cabinet. When you run your fingers over the surface, it has a slimy or oily residue is on the surface. In fact, it is neither of those that you feel. What you’re actually feeling is moisture attracted from the atmosphere, like the moisture attracted to the outside of a glass of cold water on a hot day. It is this moisture attraction that caused a spike in carpet moisture during humid conditions and caused more re-soiling to occur.

Within the last few years, we have seen some brand new chemistry evolving. These new chemistries (let’s call them third generation encapsulation chemistries) have re-written many of the old rules we were taught. The most intriguing of these new chemistries uses entirely new solvents and surfactants. These new solvents and surfactants dry down into a powder on their own, without the need for other additives like acrylic copolymer embrittlement agents. This eliminates the problems associated with entrapped, soiled acrylics. In Snell capsule tests, it was found that this new chemistry actually causes soils and old cleaner residues to dehydrate beyond their natural state, drying into a powder along with the leaning chemical. They are then vacuumed out as a dry soil at a later date. These new chemicals literally strip all the soil and old residue off the carpet fiber, leaving the fiber residue-free, much like the carpet fiber was when it was new…and we all know how easy it is to vacuum soil out of new carpeting. This is called “dehydration phase cleaning” meaning the cleaning process continues as the residues dry.

Additionally, the new “third generation encapsulation chemistry” has none of the ingredients that tend to slow or inhibit drying like acrylics, fluorocarbons and perfumes. Many people don’t realize the negative impact perfumes or fragrances have in their carpet cleaning chemicals.  These additives are fragrance oils and will impair a chemical’s ability to dry down into a powder. In fact, these oils will never dry into a powder on their own and greatly impact a cleaning chemical’s ability to dry fast and fully. These oily residues also attract and hold soil. The best of the new “third generation” chemistries do not have any oily compounds added, allowing them to dry quickly and thoroughly. This new approach has greatly improved resistance to re-soiling.

One of the more interesting characteristics of this “new” chemistry is that it appears that the chemical residue itself continues the cleaning process as it goes through its dehydration phase. That means improvements can be achieved with its use in all carpet cleaning methods.  Hot water extraction (HWE), bonnet cleaning, foam shampooing, powder extraction, spotters and stain removal, sanitizer rinsing and the new low moisture cleaning operations utilizing dual cylindrical counter-rotating brush machines. These new chemistries have re-ignited great interest in low moisture methods that were traditionally questioned because they were known to leave residues that contributed to re-soiling. Now we have chemistries that use the residues as part of the cleaning process making all the low moisture methods very appealing again.

This brings us to the question regarding deep restorative cleaning. With the advent of these new chemistries, we are only relying on the equipment for the agitation while letting the chemical do all the work. It means all methods using this “new” chemistry now have the ability to exhibit a deep restorative impact on many carpets. The good news is that the chemistry is beginning to evolve at an increasing rate, creating great expectations for the future.

Of course, there are a few simple tests one can do to substantiate what I have written here and allow you to gain a deeper understanding of carpet cleaning chemistry. In fact, if you are responsible for the cleanliness of any substantial amount of carpet, you really should strive to educate yourself on the chemistry. One simple test is to place five to six evaporation trays (or jar lids) on a table, put 1/2 oz. of water in one as a benchmark for drying time, also put 1/2 oz. of any carpet cleaning product you can find into each of the other trays. Monitor them while they go through their dehydration phases. Water will generally dry the fastest (and many “third generation” chemistries will dry at the speed of water due to their lack of oils and other additives). You will find that many traditional chemicals used on carpet actual look like a gelatin after drying for a day. After two to three days, feel the residues with your finger, many will be so sticky that you’ll be able to lift the tray.

Those concentrated samples are exhibiting extreme re-soiling characteristics in the primary chemical platform. Obviously, we could dilute the material with a quart of water and wait longer for the results, but the ability for water to evaporate is not in question in the first place. All it tends to do is make it difficult to examine and evaluate the residues without specialized equipment. The key is to do these tests yourself and then make your own decisions.

The second simple test is to find a highly soiled (yet inconspicuous place) where you can put about 1/2 oz. of raw chemical. My favorite location for this test is the driver’s side car mat of your car. Agitate it slightly but do not blot it out. The goal is to leave as much raw chemical in that spot as possible. After about a week, check that spot. One might expect to see a dark, black spot that has developed from soil adhering to all the residues. A true, state-of-the-art, “third generation” encapsulation chemical will remain clean even though the undiluted product was used. This extreme test truly shows how new and unique this chemistry is.

The final test is to take any high traffic area, clean it as thoroughly as possible using whatever chemical or equipment is available to you. Locate a four foot area in the center of the lane and clean it again with a true “third generation” chemical diluted appropriately. After a week or so of traffic, you’ll begin to see that area remaining cleaner than the rest, truly demonstrating that it is releasing soils faster and more freely than the area around it.

On a final note, don’t feel obligated to take my word on this. I implore you to do these tests for yourself. That’s the only way you’ll fully understand how superior these new chemistries are. You have a right to know about them and should have a deep curiosity to explore and understand it for yourself. After all, for many of us, carpet cleaning is more than what we do, it’s who we are…and our customers expect us to be fully educated on it.

Mark Warner is the IICRC Hard Surface Division Chair and President of Americhem International. Mark is also the President of Ameritech Business Development Services, Inc. and the Past President of the Low Moisture Carpet Cleaners Association (LMCAA)

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