Game Plan: Soil Extraction
The purpose of the “Game Plan” is to explore in detail the technical or mechanical process of cleaning carpet. This process involves following the steps set forth in S100, the Standard and Reference Guide for Carpet Cleaning, as set forth by The Clean Trust. Those steps are:
1.Dry Soil Removal
4.Finishing or Grooming
Previous conversations centered on the first two steps, dry soil removal and soil suspension. Executing these two steps thoroughly is critical to removing the maximum amount of soil from the carpet. If we have done the first two steps well, the third step – soil extraction - is an easy rinse. Failing to fully execute steps Nos. 1 and 2 usually means that we’re trying to suspend soil at virtually the same time we are trying to extract it. This will sometimes work for lightly soiled areas, but will fail to remove soil in the heavily soiled areas.
It cannot be stressed enough that the four fundamentals of soil suspension (TACT: temperature, agitation, chemical, time), must all be utilized to their maximum potential in each situation to fully suspend the fluid soil. Every cleaning situation is different; therefore the approach to cleaning must be different.
I had a student in a CCT class who cleaned a lot of restaurants, typically as often as once a month. He would start as soon as the restaurant closed, vacuum the carpet and then apply an enzyme-loaded pre-spray. He would concentrate the pre-spray in the highly soiled areas, which in a restaurant often consist in the areas from the kitchen out into the dining area. He would then agitate and allow a dwell time of up to four hours before rinsing with a rotary extraction tool. Why such a long dwell time? It wasn’t always four hours, but from experience, he knew that if the soil, in this case heavy protein soil, is not fully suspended, then it is not going to be easily nor fully removed with the rinsing process. When I tell this story to other cleaners, they are usually incredulous. They can’t envision spending that much time on just the soil suspension phase. But the cleaner who used this process understood what he was trying to accomplish and had no problem with it. Neither did his client, who was paying to have his carpet cleaned as thoroughly as possible.
I think we sometimes lose sight of what our mission is: to safely remove the maximum amount of soil from the carpet. For some, the goal seems to be to get in and get out as fast as possible. There’s nothing wrong with being economical with our time, as long as we are also as efficient as possible. I often have students ask me how long it should take to clean a typical three bedroom house. I would tell them that I wasn’t being flippant, but that it will take as long as it takes, that there are numerous variables to be considered.
As we move the conversation into the soil extraction phase of the cleaning process, it is helpful to again refer to the process used to clean clothes. As previously noted, the soil suspension phase of the washing cycle is by far the longest part. It is critical for the machine maker and the detergent manufacturer that the maximum amount of soil is removed from the clothing, otherwise there will be some unhappy users. The soil suspension phase of washing clothes is followed by two or three rinsing cycles, effectively removing all of the suspended soil. The carpet cleaning process has to mimic that of the clothes washing process, thoroughly rinsing out all of the suspended soil.
The latest version of S100 refers to the next phase of the cleaning process as “suspended soil removal.” This is perhaps a little more encompassing than soil extraction since “extraction” is identified with hot-water extraction, one of the recognized methods of cleaning carpet. Therefore, to discuss the various methods of soil removal, we need to look at the cleaning methods that incorporate the various methods of removal. Next month, we’ll look at the rinsing method of soil removal, which is arguably the most common form, particularly for residential carpet cleaning.
Bulletin Board Material
“Show me someone who has done something worthwhile, and I’ll show you someone who has overcome adversity.”
- Lou Holtz