Deep Cleaning Extractors and Systems

SOA Deep Cleaning Extractors and Systems Provide Superior Results

Regular professional cleaning is as important to your carpet as having a trained mechanic perform routine maintenance on your car. What vacuuming and spot cleaning miss, extraction cleaning should fix. CRI tests deep cleaning extractors and deep cleaning systems: the ones professionals use. The extractor is the machine, while the deep cleaning system is the combination of that machine and a particular cleaning solution, following a set procedure.

Seal of Approval Soil Removal Graph
Seal of Approval Lables

Careful Measurement Leads to Superior Performance

The CRI Seal of Approval program tests the effectiveness of deep cleaning extractors and systems. To qualify for the Seal, extractors must meet stringent standards in all three test categories:

  • Soil removal — CRI uses NASA-enhanced x-ray fluorescence technology to measure the precise amount of soil removed from the carpet, and soil removal efficiency is rated on four levels. Extractors that exceed average soil removal levels receive a Bronze Seal rating. Those achieving higher levels of soil removal receive a Silver or Gold rating. Extractors that remove the highest level of soil earn the CRI Platinum Seal of Approval.
  • Water removal —  The extractor or system must remove most of the moisture resulting from a wet cleaning process.  Dirty water that remains in the carpet could be a source of fungal growth and could prolong the drying process.
  • Texture retention — The extractor must not harm the carpet pile.

If a system is being tested, additional test criteria are included and mirror those from the Cleaning Solutions protocol. These include the following:

  • Rate of resoiling — This ensures that the product does not attract dirt to the cleaned areas faster than the rest of the carpet.
  • pH — A more neutral pH ensures that carpet dyes and fibers are not adversely affected.
  • Optical brighteners — None are allowed, as they can leave some patches of carpet lighter than the rest.
  • Colorfastness — Products must not be so aggressive that they cause a color change in the carpet.

Additional Technical Testing Information

Testing for soil removal: To test for soil removal performance, the independent laboratory uses a “designer” soil that has properties similar to soil found in carpet across the United States. A significant new element to this testing protocol is the use of x-ray fluorescence (XRF) technology, which was developed by private industry and enhanced by NASA for the Space Shuttle program. XRF enables the laboratory to identify and quantify the various compounds found in the soil. Using the XRF analyzer, laboratory staff measure the starting concentration of each compound applied to the carpet sample (following ASTM protocols) and, following cleaning with an extractor, quantify the precise amount of soil removed.

Testing for residual water: To measure how well an extractor recovers water, the test carpet sample is weighed before and after the standardized process to determine how much water remains.

Testing for texture retention: Finally, surface appearance change in the carpet pile, as a result of extraction cleaning, is measured using CRI’s Texture Appearance Retention Reference Grading Scales, which provide a visual aid in assessing appearance change in carpet.

Deep Cleaning Extractor and System Testing Criteria

Deep Cleaning Extractors Testing Criteria

To qualify for Seal of Approval, extractors must meet testing requirements for three important elements of performance. Each of these tests is explained in the brief overviews below:

1.  Standard Test Practice to Evaluate Cleaning Effectiveness of Carpet Cleaning Equipment Using X-Ray Fluorescence

X-ray Fluorescence (XRF) is used to detect elements of each compound used to soil a control carpet, then to determine their concentrations after a cleaning process. XRF is a technique that detects elements by ionizing the constituent atoms and recording the characteristic energy signatures given off by the elements as they seek to regain greater stability.

Five compounds containing suitable elements for XRF detection were chosen with consideration given to particle size (Fe3O4 at < 1 micron to ZnO at < 74 microns), hardness, solubility, and surface characteristics.

Each compound is first applied to nylon pellets at 6 grams of compound per 1000 grams of pellets (3g/1000 for strontium carbonate). Fifty grams of each of the five compound coated pellets are used to soil a 400 square-inch carpet following procedures found in ASTM-D 6540. Each soiled carpet is vacuumed with a straight suction air tool before it is scanned using XRF to verify the starting concentration of each compound. All XRF scans are with the carpet on a conveyor such that in the 3-minute scan approximately 120 square inches of the 400 square inch carpet are analyzed. The soiled test carpet is then cleaned with the extraction equipment submitted for evaluation. Two wet and two dry passes at 1.0 foot / second are applied unless otherwise specified. Three samples per test are used and the average result for amount removed is reported.

  • Soil Removal Standard – Percent of soil removed after water only cleaning operation.
    • 55 – 69% to obtain SOA Bronze Certification
    • 70 – 79% to obtain SOA Silver Certification
    • 80 – 89% to obtain SOA Gold Certification
    • 90 – 100% to obtain SOA Platinum Certification

2.  Standard Test Practice for Determining Residual Moisture as a Result of Water Extraction

This test practice is intended to determine the moisture left in a specific carpet as a result of simulated cleaning with a standard hot water extraction machine. The resultant difference in weight is measured and reported as ounces of residual moisture per square yard.

  • Residual Moisture in carpet immediately after cleaning operation.
    • ≤ 271 g/m2 (8 oz/yd2)

3.  Standard Test Practice for Determining Surface Appearance Change as a Result of Wet Extraction

This test practice provides a laboratory test for the measurement of surface appearance change of textile floor covering as a direct result of multiple cleaning passes in a controlled environment.

This test practice is applicable to all residential/commercial cleaning systems. Six cleaning cycles are applied to residential cut pile carpet for residential specific systems. Eleven cleaning cycles are applied to commercial cut pile carpet for commercial specific systems. Texture appearance change is visually rated.

  • Appearance Retention:
    • No more change in the deterioration of the carpet pile surface than Standard CRI Photographic Reference Scale.
CRI Test Method 118 (241 KB)

Laboratory Test Procedure for Seal of Approval Deep Cleaning Extractors.

Deep Cleaning Systems Testing Criteria

1.  Soil Removal Standard
This test practice utilizes the use of X-Ray Fluorescence (XRF) to measure the average percent removed by weight of compounds used to soil a test carpet. This test practice may be used to evaluate the effectiveness of a cleaning event, an event in a process of several events or the entire system.

Method: X-ray Fluorescence (XRF) is used to detect elements of each compound used to soil a control carpet, then to determine their concentrations after a cleaning process. XRF is a technique that detects elements by ionizing the constituent atoms and recording the characteristic energy signatures given off by the elements as they seek to regain greater stability.

Five compounds containing suitable elements for XRF detection were chosen with consideration given to particle size (Fe3O4 at < 1 micron to ZnO at < 74 microns), hardness, solubility, and surface characteristics.

Each compound is first applied to nylon pellets at 6 grams of compound per 1000 grams of pellets (3g/1000 for Sr). Fifty grams of each of the five compound coated pellets are used to soil a 400 square-inch carpet following ASTM-D 6540. This test method uses a drum lined with the test carpet and is rotated a specified number of revolutions to uniformly distribute the synthetic soil into the carpet pile. Each soiled carpet is scanned using XRF to verify the starting concentration of each compound. All XRF scans are with the carpet on a conveyor such that in the 3-minute scan approximately 120 square inches of the 400 square inch carpet are analyzed. The soiled test carpet is then cleaned following the cleaning system procedures as specified by the cleaning system client. Three samples per test are used and the average percentage removed results reported.

  • Soil Removal Standard – Percent of soil removed following the system providers supplied instruction:
    • 55 – 69 % to obtain SOA Bronze Certification
    • 70 – 79 % to obtain SOA Silver Certification
    • 80 – 89% to obtain SOA Gold Certification
    • 90 – 100% to obtain SOA Platinum Certification

2.  For Accelerated Re-soiling Propensity of Pile Yarn Floor Covering
This test method is intended to determine the effects of cleaning equipment, chemistry and technologies on the re-soiling properties of a specified floor covering. A clean control test carpet is cleaned according to the client’s directions. The cleaned carpet is allowed to thoroughly dry then soiled per ASTM 6540-2000. Additional control carpet is soiled per ASTM 6540-2000 that has not been cleaned. The differential soil level between the cleaned sample(s) and control sample(s) is evaluated using an appropriate laboratory instrument (spectrophotometer) using the AATCC Gray Scale for Color Change.

  • Equal to or better than water according to the AATCC Gray Scale

3.  For Determining Residual Moisture as a result of Deep Cleaning
This test practice is intended to determine the moisture left in a specific carpet as a result of simulated cleaning using a deep cleaning system.

The resultant difference in weight is measured and reported as grams per square meter and ounces per square yard of residual moisture.

  • Residual Moisture in carpet immediately after cleaning operation:
    • ** When using pre-spray, allow up to 678 grams/m2(20.0 oz/yd2)
      • 271 g/m2 (≤ 8 oz/yd2 )**

4.  For Evaluating Surface Appearance Change due to Repeated Cleanings
This test practice provides a laboratory test for the measurement of surface appearance change of textile floor covering as a direct result of multiple cleaning passes in a controlled environment.

This test practice is applicable to all residential/commercial cleaning systems. Six cleaning cycles are applied to residential cut pile carpet for residential specific systems. Eleven cleaning cycles are applied to commercial cut pile carpet for commercial specific systems. Texture appearance change is visually rated.

  • Appearance Retention:
    • No more than one step appearance change in the deterioration of the carpet pile surface.

5.  Colorfastness To Light
Cleaning chemical residues present on pile yarn floor coverings have been known to adversely effect dyes and accelerate color change. The level to which a chemical residue contributes to color change is determined by exposing a chemically treated standard test carpet with an untreated control sample to accelerated light in accordance with AATCC test Method 16. Accelerated color change in the treated test carpet is compared to the untreated test carpet after exposure.

  • No color change

6.  For Determining the pH of Cleaning Chemicals Intended for Use on Carpets
Chemicals which are extremely acidic or alkaline have been known to adversely effect dyes, treatments and fibers. Chemicals with a more neutral pH are generally considered safer to use when cleaning carpets or rugs. The formula is tested by a standard pH meter following the manufacturers recommended dilution.

  • pH between 4 and 10

7.  For Determining the Presence of Optical Brighteners in Cleaning Chemicals
The presence of optical brighteners in carpet cleaning products has been known to adversely affect fiber color, appearance and long term performance. The cleaning agent is evaluated for optical brightener content using fluorescence.

  • No Optical Brighteners

​​Seal of Approval Deep Cleaning Systems Test Program Protocol

  • CRI Test Method 119 (601 KB)

    Laboratory Test Procedure for Seal of Approval Deep Cleaning Systems.

  • CRI Test Method 120 (53 KB)

    Standard Laboratory Test Procedure For Evaluating Cleaning Effectiveness of Commercial Carpet Cleaning Chemicals, Cleaning Equipment or Complete Cleaning Systems.