Chemical acceleration and lubrication for better spot bleaching

Bleaching is removing stains by camouflaging. The stain is made invisible by adding or removing oxygen. Bleaches can be accelerated by heat and concentration. Chemical acceleration is used when the normal bleaching process does not work. Chemical acceleration is very effective because the activating chemical enters into the chemical reaction making the bleach more effective. It will often be noticed that the accelerated chemical may change the color of the stain. This is an indication that the chemical reaction is working. It must also be remembered that the accelerating chemical can also affect the dye on a fabric. For example, when peroxide is applied to a colored silk no discoloration may occur. When ammonia is added for acceleration the color of the silk will be affected. When bleaches are accelerated it also removes the existing bleach from the fabric.

Lubricants added to a bleach have been found to improve the performance of the bleach. The lubricant softens the fabric, the stain and provides better penetration for the bleach. When spot bleaching, the bleach should be applied when the garment is on a towel to keep the area localized. The bleach should be applied with a q-tip or it can be applied with the tip of a spatula. We are also adding lubricant for its ability to provide a better flushing action of the chemicals.

HYDROGEN PEROXIDE

This is a common oxidizing agent for spot bleaching. It should be used in 3% or 6% concentration. It is effective for last traces of tannin, protein, ink, dye and scorch. It is activated by alkali. The best alkali to use is ammonia but protein formulas can also be used. 

PROCEDURE

• Wet area.
• Apply lubricant.
• Apply peroxide.
• Apply ammonia.
•  
• Flush
• Neutralize with acetic acid or tannin formula.
•  

Caution-Test colors

SODIUM PERBORATE AND SODIUM PERCARBONATE

These bleaches come in powder form. The bleaching action is similar to hydrogen peroxide. They are bath bleaches but many experienced spotters like the concentrated bleaching effect on stains. They are alkaline by nature but still accelerated by more alkali. They are effective on the same types of stains that hydrogen peroxide is.

PROCEDURE

• Flush
• Apply lubricant
• Apply bleach
• Apply protein formula or ammonia
• Heat
• Flush
• Neutralize with acid
• Flush

SODIUM HYPOCHLORITE

This is a strong oxidizing agent and is effective for removing mildew, ink, tannin, protein and dye. It can not be used on wool or silk. It should be diluted first by making a 5.25 concentration of bleach into a 1% concentration. Then mix 10 parts water with the 1% concentration. I tell my students to purchase a bleach stick at the supermarket for easier usage. Chlorine bleach is accelerated by acid.

PROCEDURE

• Wet area
• Apply lubricant
• Apply bleach
• Apply acetic acid or tannin formula
• Heat
• Flush

Note: The acid applied not only accelerates the bleach but causes the bleach to be used up which effectively removes it from the fabric.

SODIUM HYDROSULPHITE

This is a reducing bleach. It is effective for removing dye. It is also effective for last traces of ink stains and some tannin. It is acid by nature and also accelerated by acid. It comes in powder form.

PROCEDURE

• Flush area
• Apply lubricant
• Apply bleach in powder or liquid form
• Apply acid
• Heat
• Flush

TITANIUM SULFATE

This is purchased as a purple liquid. It is reducing bleach that is very effective for removing dye, fugitive dye, ink and last traces of some tannin. It may cause some discolorations when in combination with other bleaches and alkali. The discoloration can be removed by using rust remover (hydrofluoric acid), The hydrofluoric acid is also used to accelerate the bleach.

PROCEDURE

• Wet area
• Apply lubricant
• Apply stripper
• Apply rust remover
• Heat
• Flush
• Apply protein formula for neutralizing rust remover
• Flush