Generally stains are understood as 'spots' or 'Marks' on a fabric, which calls for immediate attention. Removing stain appears very simple and easy but practically even a small stain involves a lot of technique and patience for the fabric to regain its new look and luster. That is why stain removal is considered as both an art out and science. Some stains are easily removed by simple ordinary methods as soaking, steeping and use of friction with soap or basic reagents. Whereas there are some stains which needs special treatment, care and techniques applied to remove the stains. Of course, the entire process of stain removal depends on the nature and composition of stain and the fabrics. A clue to the identity of a stain is its colour, smell, appearance and texture.
Types of Stain
Stains are classified according to the nature of the stain. They are:
1. Animal stains:
Stains caused by substances of animal origin. Examples are blood, egg, milk, meat, juice. All these stains contain protein matter; hence heat must be avoided in removing such stains.
2. Vegetable stains:
This category of stains is of vegetable origin. Examples are tea, coffee, grass fruits, wine. These are acidic in nature and should be removed by alkaline reagents.
3. Grease stains:
There may be either vegetable or animal fat, with coloring matter fixed on the fabric. Examples are oil, paint, varnish, ghee, butter. Grease solvents and absorbents are used to absorb and dissolve the grease.
4. Dye stains:
These may be acidic or alkaline in nature and required specific reagents for their removal.
5. Mineral Stains:
Examples are iron rust, mould, black ink, certain medicines etc.
General Rules of Removing Stains
Successful removal of stains from fabrics depends on certain basic principles or rules. These rules are to be followed with utmost caution. They are-
1. First decide, whether the fabric with stains is washable or not, as the process to be used varies according to the type of fabrics.
2. Never allow the stain to set. Remove the stains while they are still fresh. As it become very difficult for the stain to remove as they become older.
3. Pretest the chemical to be used in the fabric, as they confirm any sort of discoloration of the fabrics later on.
4. Study the nature and texture of the fabric when chemical reagents and bleaches are used. Dilute solutions should be used as far as possible.
5. Hot water should never be used on an unknown stain. The heat will set the stain, making it more difficult to remove.
6. All acid reagents should be neutralized with alkaline rinse and vice versa.
7. Treat known stains with specific reagents. Unknown stains should be treated with simple methods as steeping in cold water, washing with soap. Then use mild reagents followed by steeping in cold water, washing with soap. Then use mild reagents followed by stronger ones.
8. All chemicals should be stored properly and handled with care, out of children. Precautions should be adopted in handling some chemicals which seem to be highly inflammable and poisonous.
Kinds of Stain Removers
As discussed earlier stain removal is both an art and science. Hence a variety of removers are used to remove stains from the fabrics that are used in our daily life. Depending on the nature of the stains, removers are used. However, the most commonly used stain removers are:
Water, Alkalis and Acids:
Water is the most popular and effective agents used in removing stains from fabrics. Acids and alkalis should be used only as mild solutions, as strong concentrations of these would damage the fabrics. Normally acetic acid and vinegar, ammonia, are commonly used in laundry work.
Various bleaching chemicals are used to remove stains. They are Javelle water, hydrogen peroxide, sodium perforate, oxalic acid, potassium permanganate, sodium hypochlorite, sodium thiosulphate, sodium hydrosulphate. These chemicals are to be used carefully in mild amount as they may extract colour and weaken the cloth.
Greasy stains are removed by solvents as carbon tetrachloride, benzene, turpentine, Stoddard solvent, ether, acetone, alcohol. These solvents should be applied on the wrong side of the fabric and sponging is most effective while applying these solvents on the stain.
Cornstarch, fuller’s earth, French chalk, white talcum powder and cornmeal are used to remove greasy stains in dry-cleaning method of laundering clothes.
Methods of Stain Removal
There are several techniques for applying stain removers. They require care and skill and are best applied when the stain is not too large. The most common stain removal methods applied in laundry work are discussed below:
When the entire fabric can be immersed in the stain remover, the best method is dipping. This is the most convenient method if the spot is large or if there are many spots on a cotton or linen fabric.
Stains on wool, silk or any colored fabric may be removed by steaming. The stained area is saturated with steam by spreading the cloth over a bowl partially filled with hot water into which a small amount of the appropriate removal agent has been placed.
In this method small drops of a removal agent can be applied by means of a medicine dropper, glass rod or orange stick.
Sponging is the most frequently used method of stain removal but if it is not done with care, it will not be effective. An absorbent cloth or a blotter should be placed underneath the stain to absorb the removal agent as well as the stains. The blotter also prevents further spreading of the wet area. Both the sponging cloth and the absorbent material should be changed whenever they become dirty or show slightest tinge of the stain.
When a stain has hardened or resist solvents, a loosner or spot softener like lard or Vaseline may be used with a small piece of cotton wound round a stick. Apply the grease or oil floater to be used. After the floater has had a chance to work use the regular grease removing method.
Use of Absorbent powders - dry cleaning method:
Make a paste of the absorbent powder to be used. Then work the powder into the stain on the right side of the fabric, rubbing gently with a blunt knife. As soon as the paste discolors, shake it or brush it off and repeat until the stain is removed. Then remove all traces of powder with a fresh cloth or soft brush.
Removal of stains from Fabrics
Before starting with the process of removing stains, all the rules and precautions discussed above are to be followed. The right reagents and the proper technique of removing stains should be thought of and planned.
The processes of removing few of the stains from fabrics are given below:
Soak in cold water, then dilute in ammonia. Wash to bleach out the dampen and leave in the sun.
Soak in cold water and wash.
Sponge with carbon tetrachloride holding gauze underneath to absorb excess of fluid.
Pour boiling water through stains from reverse side. If persistent repeat after covering stain with glycerin.
Soak in borax solution, rinse or keep stain moist with lemon juice, then expose to sun for a day or two.
6. Fruit juice:
Swab with warm water. If persistent sponge with cold water, rubbing in a few drops of glycerin. Allow to stand for 2 or 3 hours, swab with vinegar.
7. Candle wax:
Scrap off wax. Place blotter over spot, iron on reverse side. If persistent, swab with carbon 'tetrachloride.
Sponge with alcohol, then with soap and water.
9. Ink (writing):
If fresh, soap and water. If dried, sponge with teach, then sponge with oxalic acid, and wash.
10. Ink (ball point):
Let stand 10 to 15 minutes in detergent seeds. Rinse If stain remains use petroleum jelly or sodium hydrosulfite. Then sponge with carbon tetrachloride.
11. Iron rust:
Sponge with oxalic acid, rings well or spread with salt. Moisten with lemon juice and place in sun.
Rub with Vaseline or lard. Sponge with carbon tetrachloride. If persistent sponge with denatured alcohol. Alternatively sponge with mixture of hydrogen peroxide and sodium perforate.
13. Nail polish:
Apply alcohol or lacquer thinner.
Sponge with peroxide and ammonia.
Moisten with carbon tetrachloride or with benzene. Scrape off, then sponge residue with same solvent.
Apply turpentine or paint remover.