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Pretesting Carpet Cleaning Products

Pretest so cleaning problems will not develop during cleaning or after the carpet or rug is cleaned.

Not all products can be safely used on all fibers and dyes. The face yarns of a carpet can be dyed by many different dye processes using a wide range of dyes. It is common in multi-colors to have different types of dyes to produce the desired color. Therefore, a cleaner may be safe on one color and not another.

To test a product, mix it according to directions or as it is planned to be used. In an inconspicuous area, such as in a corner, behind a chair, in back of the drapery, etc., place approximately one teaspoon of the solution on a spot about the size of a nickel. Work the solution in with the fingers, press a white tissue against the wet spot and hold it there for about ten seconds. Examine the tissues to see if any dye has transferred. The amount transferred may be very small and difficult to see on the tissues, but over a large area of carpet it could be objectionable. If the small spot tested does not include all the different colors, then the others should be tested. Retest any color that may be in doubt. The wet spots should be carefully examined as they may show a change not apparent on the tissues.

This testing should show any damage or change that may take place on the fibers. The chance of damage occurring with a cleaning solution is very small, but some spot removal chemicals can damage some fibers. The fibers may become sticky, soft, or dissolve. Always test and examine carefully to prevent being sorry later.

If, during testing, a dye transfers or it appears as though a fiber is being damaged, then this product should not be used. Try testing other products until a safe one is found. If none can be safely used, then contact and explain the problem to a professional.

A second test will determine the type of residue that remains after the carpet or rug has been cleaned. The cleaning solution is made up of various chemicals and liquids. After this is applied, the liquid will start to evaporate. The drying time will vary from several hours to several days.

After the liquid evaporates, what type of material remains on the fibers? If it is a powdery, granular material, it will be removed with the vacuum. Any other consistency will remain on the face fibers.

To determine the type of residue, pour one-half cup of the product as it is to be used in a glass pie plate. Allow the pie plate to set undisturbed until all the liquid has evaporated. This may take several days. The process can be speeded up by placing the pie plate, with solution, in an oven at 160 F. Watch and remove the plate when no more liquid is being evaporated.

Examine the residue that remains. Is it sticky? If so, it will hold onto soil at an accelerated rate and make the carpet soil faster. The sticky residue will also hold the fibers together and the surface of the carpet will be more matted and less resilient. A hard, waxy residue will not hold onto soil to the same extent but it will dull the surface and the fibers will not appear bright and clean.

Once the sticky or waxy residue gets on the fibers, it usually remains until the residue is flushed out with a lot of warm water. Another cleaning with the same solution will only build up the residue. If it is suspected that a residue is already present on the carpet yarns, place a tablespoon of warm water on a spot and work it in with the fingers. A foam or a slippery feeling will indicate a detergent residue. The best way to remove it is by the hot water extraction method. Many professional rug cleaners have this type of equipment or it can be rented.


This article was written by Anne Field, Extension Specialist, Emeritus, with help from Margaret Boschetti, previous Extension specialist and the Carpet and Rug Institute.

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This information is for educational purposes only. References to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned. This information becomes public property upon publication and may be printed verbatim with credit to MSU Extension. Reprinting cannot be used to endorse or advertise a commercial product or company.

MSU is an affirmative-action, equal-opportunity employer. Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status. Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Thomas G. Coon, Director, MSU Extension, East Lansing,MI 48824. This information is for educational purposes only. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.

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