Core Technology for Professional Laundries: Classification & Accurate Removal of Common Stains

In the daily operation of the laundry shops, high-efficiency and safe removal of all kinds of stains is the most direct criterion to measure their professional levels. When facing complicated stains on the clothes sent by customers, from common oil stains and coffee stains to stubborn ink stains and cosmetic stains, a scientific and systematic stain removal process is not only the key to ensuring good washing quality but also the basis to build trust and show a professional image. This article deeply analyzes the solution based on chemical characteristics of the stains for all practitioners in laundry shops, and aims to improve the overall service and technological competitiveness.

Dry cleaning is cleaning clothes without water. It only uses stain remover to remove oil marks or stains. There is barely any water in stain removal solvent, so this method is called dry cleaning.

Dry Cleaning Steps

Step 1: Pre-treatment

That is stain removal treatment. It is an artificial process that uses additives to pre-treat severely contaminated dirt and stains that are insoluble in dry cleaning solvents. (such as fruit juice, nail polish, paint, ink...)

Step 2: Main wash

Put clothes that have been pre-treated in the dry cleaning machines and use dry cleaning solvents to do comprehensive cleaning and drying.

Step 3: Post-treatment

The main purpose is to remove the residual dry cleaning solvents and use ironing to reshape the clothes. 

Common Stain Removers

Common stain removers used in laundry shops are rust remover, degreaser, acetone, banana oil, hydrogen peroxide, oxalic acid, sodium hypochlorite solution, whitening laundry detergent, etc. Each stain remover has different usage skills and precautions.

● Rust remover and oxalic acid are mainly used to remove rust stains and some grass stains. They are highly acidic and may cause discoloration on a few dyes. Once discoloration occurs, immediately clean with concentrated laundry detergent solution or sodium carbonate solution to restore the color. In addition, rust remover is mainly used for local stain removal, while oxalic acid is mainly used for overall soaking to remove large-area rust stains and grass stains. The dosage should generally not exceed 10 grams per liter of water, and the water temperature should generally not exceed 40 degrees Celsius.

● Acetone is mainly used to remove oil stains and super glue, but it can damage acetate fiber and down jacket coatings. It should be used with caution on these two types of clothing and must not be applied to the clothing for a long time.

● Banana oil is mainly used to remove paint, ink, nail polish, etc., but it is not suitable for removing blue paint.

● Solvent-based degreasers have a good degreasing effect, but they may dissolve and fade some clothing, such as gray and brown casual wear. In addition, they may also dissolve down jacket coatings. For these two types of clothes, you can first test in a hidden area before using an appropriate amount.

● Hydrogen peroxide is mainly used for yellowing removal, bleaching, and pigmented stain removal. However, if the water quality is poor (metal ions such as rust) or the clothing is equipped with metal decorations such as iron buckles and copper buckles, it must be used with caution. Otherwise, it may easily cause clothing discoloration or even damage.

● Sodium hypochlorite solution is mainly used for bleaching and stain removal of white clothes. It has a low cost and good effect, but the accident rate of blind use is high. Sodium hypochlorite solution is best diluted and used with whitening laundry detergent, which can prevent white clothes from turning yellow, reduce clothing damage, and lower the accident rate. For local use, you can first apply soap and then use diluted 84, which has the same effect. In addition, sodium hypochlorite solution is strictly prohibited for protein fibers such as real silk and wool fabrics. Otherwise, it will easily cause protein denaturation and yellowing, which is difficult to remove.

Common Stain Types

There are main types of stains. Different stains have specific cleaning products for removing special stains. Not every kind of stain can be removed with the same cleaning product. Common stains can be divided into 

● Wet Stains

Sugar Stains (beverages, fruit juices, tea, wine...)

Oil Stains (edible oil, asphalt, paraffin...)

Tannin Stains (coffee, tea, beverages, fruit juices, wine, Baijiu, tobacco...)

Protein Stains (eggs, milk, ice cream, blood stains, sweat stains, urine stains, feces...)

Dye Stains (fountain pen ink, ballpoint pen oil, lipstick, dyes, medicines...)

Metal Stains (rust stains, blood stains)

● Dry Stains

Paint, glue, coatings, wax...

Tips for Stain Identification

To successfully remove stains from clothes, it is essential to correctly identify them. This ensures the right processes and methods are used for stain removal.

● Touch

How does the stained area feel? If it is hard, it may be paint, glue, or varnish. If the stain is fresh, the area will spread when rubbed. If it is soft, it may be from beverages, food, or lipstick.

● Smell

If the stain is not long-standing, its odor can help with identification. Sweat, perfume, alcohol, vomit, medicines, and some foods each have distinct smells.

● Color

Yellow to brown stains are often tannin, coffee, tea, rust, sugar, urine, scorch marks, perfume, or blood. Blue stains are usually ink, ballpoint pen marks, or vegetable juice. Red stains are commonly ink, ballpoint pen marks, lipstick, nail polish, or red wine. Black or gray stains are typically tar, grime, dust, grease, or ink.

● Appearance

Stains that only remain on the fabric surface are called surface stains. These mainly include paint, tar, and adhesives. If the stain penetrates the fabric and is visible on both sides, it is called an absorbent stain. Such stains mainly include beverages, ink, blood stains, etc.

Five Stain Removal Methods

Special and stubborn stains cannot be removed by ordinary washing methods. They must be treated with dry cleaning-specific detergents and washing methods.

● Rinsing Method

Place the garment on a stain removal table → apply the stain remover → let it sit for a few minutes → rinse with water using a stain removal gun (from low pressure to high pressure gradually)

● Scrubbing Method

Laundry shops use soft boar bristle brushes. For home use, a soft-bristle toothbrush works. This method is effective for most sugar stains, protein stains, tannin stains, and oil stains. 

Apply the stain remover to the garment → let it sit → soak the garment in cleaning powder dissolved in cold water → gently tap the stain surface with the back of the soft brush → the stain softens → lightly scrub → stains are removed.

● Scraping Method

Stains such as paint, sugar stains, and various glues need this method.

Apply the stain remover to the surface → the remover penetrates and dissolves the stain → gently scrape it off with a scraper (stain removal horn).

● Soaking Method

This method is suitable for old and stubborn stains. 

Apply the stain remover to the garment → fully soak it in cleaning powder solution.

● Absorption Method

Delicate fabrics: pure silk, wool, velvet, and fur

Apply the stain remover to the stain → let it dissolve → use a cotton cloth to blot and gently wipe both sides of the stained area → transfer the stain to the cotton cloth →  wipe the area clean with a fresh cloth.

Conclusion

Mastering the scientific stain removal technology means laundry shops can upgrade the basic service of cleaning to the precise care that can solve the actual pain points of customers. This not only greatly reduces the customers' complaints caused by residue but also establishes a vivid reputation in fierce competition by the ability to solve complicated problems. All practitioners are recommended to combine this guide with the daily practice and continue to build their own case library. Every success of stain removal is a strong advertisement for your laundry shop.

As a professional brand of commercial and industrial washing machines and dryers, Kingstar knows that scientific stain removal is not an isolated part. It is closely linked to the following washing and drying process. Kingstar uses professional laundry equipment solutions to build a full-process quality assurance system for laundry shops that includes “scientific stain removal - safe washing - efficient drying”. With Kingstar solutions, laundry shops can solve customers’ pain points with their good stain removal technology and also consolidate the service effect through stable following processing links. This helps strengthen the professional image and accelerate the customers’ trust in the market competition.