Function of Washing Chemicals

Potassium permanganate

Chemical names which are used in washing plant 

• Enzyme
• Acetic acid [CH3-COOH]
• Detergent
• Ant staining agent
• Bleaching powder [ Ca (OCl) CL]
• Sodium hyposulfite [Na2S2O2]
• Caustic soda [NaOH]
• Soda ash [Na2CO3]
• Sodium bicarbonate [NaHCO3]
• Potassium permanganate [KMnO4]
• Cationic/ nonionic flax softener
• Micro emulsion silicon
  
• Salt
• Buffer
• Hydrogen peroxide [H202]
• Stabilizer
• Fixing agent
• Optical brightener
• Resin

 Function of washing chemicals:

Anti-staining Agent 

A mixture of special macromolecules and surfactants, especially for anti-back staining during desizing and washing in denim rinsing. The basic problem in enzymatic washing of denim is back- staining of detached indigo dyes on fabric surface. Hence, it reduces the contrast effect/fading effect, which garment washer want to produce on denim. 

Characteristics and advantage:

1.  Has good emulsifying, dispersing and absorbing ability for indigo dyes, can revent indigo back staining and improve color contrast and fabric brilliance.
2.  Can improve color fastness after stone washing.
3.  Be used with enzyme or used general washing process, improve effect of washing.
4.  Be high concentrated, dilute it before using, stable diluted solution, easily used.

Potassium Permanganate 

Fig: potassium permanganate

After desizing it is sprayed in garments area, It helps for color out from garment during Enzyme wash. Potassium permanganate (KMno4 + H3Po4 + H2O) solution applied or stray on the garments so oxidizes the cellulose & color is partially removed according to the intensity & solution. 

The process of acid washing jeans used chemicals, stripping off the color of the top layer, leaving the white fabric exposed. The color remained in the lower layers of the material, giving it a faded look. Acid washing could be done overall or made to look splotchy treated with potassium permanganate. 

 Caustic soda (NaOH)

Caustic soda is a deliquescent white crystalline solid, which readily absorbs moisture and carbon dioxide from the atmosphere. It is used for mercerizing cotton. 

Function of caustic soda 

• Caustic is the strong alkali used in garments washing to introduce an alkaline condition.
• Caustic created the role in bleach technique without color change the garments.
• Caustic has a cleaning power which is more powerful than soda Ash.
• Fading affect/old looking affect come rapidly on garments by the action of caustic soda.

SODA ASH (Na2Co3) 

Sodium carbonate is a white crystalline solid containing water of crystallization. It is used in laundry as washing soda. It is also used for softening water. 

Function of soda ash 

• Soda ash created alkaline medium for the breakdown of pigment dye.
• It has a cleaning power.

 

Detergent 

Detergent is used to remove impurities from the Garment fabric surfaces and temperature helps detergent to enhance its action. During coming these impurities, some pigment will be washed out from the pigment dyed or printed area of the garments. As a result fading affect will be developed.

The simplest way to inactivate any detergents left in the fabric is to neutralize the pH to between 6.5 and 7.5 through addition of a small amount of acetic acid. Through this method, the activity of the alkali and surfactants is eliminated. 

 Acetic Acid (CH3COOH) 

Acetic acid is a colorless and corrosive liquid with pungent smell of its own. It is miscible with water, alcohol and ether in all proportions. Acetic acid is used in garment industry for dyeing purposes. 

Acetic acid is a weak organic acid - the key ingredient in vinegar. It is readily degradable and has no adverse effects in the environment except for the use of oxygen for degradation. It is also readily degradable under anaerobic conditions.4 

Function of acetic acid 

• Acetic Acid is used to neutralize the garment from alkaline condition and to control the pH value in wash bath.
• Acetic acid is not a fabric softener in principle but is often used for this purpose in professional laundries.4
• Acetic Acid is used in Enzyme bath
• Acetic acid has to be stored and handled with care

Function of sodium Meta bi sulphite 

• Sodium metabisulfite is used as a bleaching agent in pulp and textile manufacture, as well as a reducing agent .
• Sodium metabisulphite is used in the washing plant to neutralized the garment from potassium permanganate.

 Softener 

Function of softener 

• The purpose of adding ‘fabric softeners’ at the end of the washing process is to neutralise the very small amounts of detergents left in the textiles and thus prevent static electricity.
•  Another main function of the softener is creating softer handle over the garments, it is obtained because when softener is applied on the garments then the each and every treads tends to slip over another.
• Softener is used to make the garments treated textiles is surface feel that is bath sickly and soft and also provides excellent lubricating properties.

 Enzyme 

The trend today is towards garment processing. This is because garment processing offers the processor better and more varied opportunities to add value to the garments in terms of fashionable looks as well as feel. In such a fast changing scenario, Enzymes are playing an important role.

Functions of Enzyme:

• Develop ‘’Bio-polishing’’ effect on denim in echo-friendly way
• Enzyme improves the ‘’Anti-pilling’’ properties.
• It attacks more the surface of the fabrics and gives a very smooth surface.
• It increases the color fastness and rubbing fastness properties.
• Achieve high-low abrasion to produce fading effect in sewing area. 2
• It just hydrolysis the cellulose, first it attacks the projecting fiber then the yarn portion inside fabric and faded affect is produced.
• It reduces GSM of the garment.
• Neutral enzyme is used for Dark shade enzyme wash because it comes fading effect slowly.
• It produces buyer loving soft feel in use.
• Acid enzyme is used for medium /light shade Enzyme wash of denim skirt because it comes enzyme effect quickly than neutral enzyme.FOB

 Bleaching Powder 

Color is produced by molecules which contain chromophores and bleach works upon these molecules to achieve the whitening effect. Oxidizing bleach breaks down the molecules with chromophores and make them incapable of absorbing any visible light, while reducing bleach converts the double-bonded chromophore to single-bonded, thus making them incapable of absorbing visible light. The same principle is behind the bleaching action of sunlight. The high energy photons of light affects the bonds of chromophores, which in turn results in the gradual fading of color .

 

Hydrogen Peroxide 

Hydrogen peroxide creates the prime role in bleach wash technique. In alkaline medium, hydrogen peroxide breaks up and gives some perhydroxhylion, which discolor the colouring materials and as a result fading effect is developed. Hydrogen peroxide is used in scouring, bleaching bath for white/ready for dyeing of gray fabric garments. It is used also neutralized the garment from alkaline condition. 

Function of Hydrogen Peroxide 

A. Hydrogen peroxide is created in the atmosphere when ultraviolet rays from the sun hit oxygen in the presence of moisture. It is basically the same chemical make up as water but with an extra

 B. Hydrogen peroxide has antibacterial and antiviral qualities and is a strong bleach. The most common form is three to six percent hydrogen peroxide solution and this works best in the home as an all-purpose cleaner. 

• Antibacterial
• Antifungal
• Kills mold
• Kills mildew

Silicone Softener

Clothing manufacturers and consumers began to see the value in fabric softeners, and an industry was born. Products like these have evolved to meet additional consumer needs, with the addition of fresh scents, dyes and the ability to reduce wrinkles, make ironing easier, and added stain protection.

The typical product contains chemicals and additives to make the fabric soft and static free. Traditionally, the chemicals deposit themselves onto the fabric, but recent formulas use technology that allows the fabric softener to actually penetrate the fabric. This improves the absorption of the fabric, which in the past has been compromised by use of these products. 

Different types of Chemicals used in washing plant:

1. Enzyme
2. Acetic acid [CH₃-COOH]
3. Detergent
4. Ant staining agent
5. Bleaching powder  [Ca(OCl)CL]
6. Sodium hyposulfite [Na₂S₂O₂]
7. Caustic soda [NAOH]
8.  Soda ash [Na₂CO₃]
9.  Sodium bicarbonate [NaHCO₃]
10.  Potassium permanganate [KMnO₄]
11.  Cationic/ nonionic flax softener
12.  Salt
13.  Buffer
14.  Hydrogen peroxide [H₂0₂]
15.  Stabilizer
16.  Fixing agent
17.  Resin
18.  Desizing agent

 Caustic Soda (NaoH) : 

1.  Caustic created the role in bleach technique without colour change the garments.
2.   Caustic has a cleaning power which is more powerful then soda Ash.
3.  Fadding affect/old looking affect come rapidly on garments.

Soda Ash (Na2Co3) :

1.  Soda ash created alkaline medium for the breakdown of pigment dye.
2.   It has also a cleaning power.
3.   It has also help colour fadding affect of garments.

Detergent:

Here detergent is used to remove impurities from the Garment fabric surfaces and temperature helps detergent to enhance its action. Detergent removes the impurities from the garments fabric surface. During coming these impurities, some pigment will be washed out from the pigment dyed or printed area of the garments. As a result fadding affect will be developed. 

Acidic Acid (CH3COOH) :  

 Acidic Acid is used to neutralize the garment from alkaline condition and to control the pH value in wash bath.

Flax Softner (Cationic, Nonionic) :

Softener is used to make the garments treated textiles is surface feel that is bath sickly and soft and also provides excellent lubricating properties.