National Clothesline

ynthetic detergents are the most important ingredient for the proper wetcleaning of textiles. The action of the detergent is necessary to condition the water to be effective for soil removal.

The surfactants present in detergents have an ability to lower the surface tension of water. Surface tension is what holds the water molecules together.

The surfactants cause the water molecules to expand and spread out, thus lowering the surface tension. This will then allow water to become wetter and penetrate the fabric better.

The surfactant ingredient in the detergent is a major factor for proper cleaning.

The fact that surfactants lower the surface tension of water may cause some detergents to suds or bubble. The suds or bubbles, however, are not an indication that better cleaning is performed.

How surfactants work

A surfactant has two distinct parts. One part is hydrophilic and is attracted to water. The other part is hydrophobic and is repelled by water.

The hydrophobic end of the surfactant surrounds dirt while the hydrophilic part pulls the dirt toward the water.

The hydrophobic end of the detergent also pushes the water molecule into the fabric and breaks up the molecule, thus lowering the surface tension of the water.

Types of detergents and surfactants

Anionic detergent. The negatively charged part of the surfactant does the bulk of the cleaning. This detergent suspends and removes soil well and readily rinses from the fabric. This can not be used with a cationic surfactant.

Cationic detergent. The positive end of the surfactant does the cleaning. This remains with the fabric and gives silk and wool a soft feel. The detergent tends to set or stabilize dyes and is considered a germicide and disinfectant but does not have the cleaning ability of an anionic detergent Acids are generally used with cationic detergents for stabilizing dye. This surfactant cannot be used with an anionic surfactant.

Non-ionic detergent. These surfactants are neutral and do not carry a positive or negative charge. They are good for removing grease and oil staining, but are not considered good soil suspenders. This surfactant detergent can be mixed with anionic or cationic detergents.

The additive of an alkali increases the grease removing properties of the detergent Many non-ionic detergents are citrus by-products. This citrus odor is present in many products.

Anionic and non-ionic surfactants are commonly mixed and used in many detergents and the manufacturer may also add chemicals, bleach and enzyme.

Rules for using detergents

• An anionic is best for soil suspension.

• Cationic is best for stabilizing dye and giving a soft feel to wool and silk.

• Anionic and cationic detergent break each other down and cannot be used together.

• Sudsing with anionic surfactants can be counteracted by using a cationic surfactant or fabric softener.

• Alkali increases the cleaning and grease removing properties of detergent. Alkali also are effective for protein stains.

• To remove chemicals from fabrics during spotting, use anionic detergent.

• Acids are used with synthetic detergent to stabilize dye. Acids are also used for tannin stain removal.

Dan Eisen recently retired as chief garment analyst for the Neighborhood Cleaners Association after 33 years with that organization. He is available for seminars, consultations and independent garment analysis. He also has published a book, “The Art of Spotting,” which is an indexed compilation of articles he wrote for National Clothesline and NCA over the past three decades. He can be reached at (772) 340-0909. His address is 274 NW Toscane Trail, Port St. Lucie, FL 34986. His e-mail address is cleandan@adelphia.net.