How to remove old ink stains

Nowadays, almost every household has a washing machine, so many people become lazy and put a bunch of clothes into the washing machine to wash together. Although it is convenient to use a washing machine to wash clothes, it also has many disadvantages. It is generally difficult to remove stains from clothes washed by a washing machine, especially for some ink stains and oil stains, which can easily cause more and more dirt on the clothes. So how to wash away old ink stains?

A vest soaked with sweat cannot be washed in hot water. Clothes stained with iodine should be soaked in hot water before washing. When textiles are stained with machine oil, you should not only wipe them but also iron them with an iron to use the heat to remove the oil stains.

It turns out that sweat contains a small amount of protein, and egg white is a type of protein. Egg whites coagulate easily in hot water. The protein in sweat, like egg white, coagulates quickly in boiling water and becomes entangled with the fibers. A sweatshirt that could have been cleaned with cold water will turn yellow on the back if you wash it with hot water, and it will not be clean. This is the benefit of soaking clothes in cold water before washing.

If clothes are stained with pure blue ink, red ink or watercolor paint, wash them immediately with detergent, then rinse them with clean water several times, and they can usually be washed clean. This is because they are made from dyes dissolved in water. If any residue remains, the dye has bonded to the fabric and must be removed with bleach. The main ingredient of bleaching powder is calcium hypochlorite, which decomposes into hypochlorite in water, a very strong oxidant. It can oxidize dye molecules and turn the dye into colorless compounds, which is the bleaching effect.

Stains of blue-black ink, blood, juice, and rust are different. They gradually oxidize in the air, becoming darker and darker in color, and can no longer be oxidized by bleaching powder. For example, blue-black ink is an aqueous solution of ferrous tannate and blue dye. Ferrous tannate is colorless, so the words just written with blue-black water are blue. After coming into contact with air on paper, they gradually oxidize and become ferrous tannate, which is insoluble in water. Iron tannate is black, so the writing gradually changes from blue to black, and it will not dissolve in water and will never turn brown. To remove the ink, it must be converted into a colorless compound. Dissolve the colorless crystals of oxalic acid in warm water and use it to wash the ink.

The ferric trace tannate combines with oxalic acid to form a colorless substance that dissolves in water. Please note that oxalic acid is corrosive to clothes and should be rinsed as soon as possible.

Stains caused by blood, juice and rust can be removed with oxalic acid, which turns rust into a colorless substance that dissolves in water.

Ink is made of extremely fine carbon particles dispersed in water and added with animal glue. When ink stains are found on clothes, the carbon particles are attached to the gaps in the fibers. They are insoluble in water, gasoline and other organic solvents, and are very stable. They are not soluble in common oxidants and reducing agents.

There is nothing you can do about it, no chemical changes will occur. This is the reason why the ink marks of our ancestors' calligraphy and paintings remain bright black for thousands of years and never turn brown.

The only mechanical way to remove ink stains is to rub them with rice grains to stick the ink off the fibers. If the ink is too thick, the ink is applied for too long, and the carbon particles penetrate deep into the fibers, it will be difficult to remove.

If the stain is oily and does not respond to water, such as ballpoint pen ink, paint, or asphalt, we have to "attack oil with oil" and wipe it with a soft cloth or cotton yarn dipped in gasoline. The main oily color substance will dissolve in the gasoline and then be transferred to the control cloth. Sometimes gasoline cannot dissolve the oil, so you can use chemicals such as benzene, chloroform or carbon tetrachloride that have stronger grease-dissolving ability.

Removing stains is like treating an illness; you need to use the right medicine for the right condition.