Scouring is the first process carried out with or without chemicals, at room temperature or at suitable higher temperatures with the addition of suitable wetting agents, alkali and so on. Scouring removes all the waxes, pectins and makes the textile material hydrophilic or water absorbent.

Scouring agent is required to eliminate the impurities effectively such as sizing agent or lubricating agent, stains from weaving process and abrasion stains which come from greige woven or knitted fabric. The required property of scouring agent varies depending on materials, fabric structure, stains and applications.

Scouring & Carbonising. Scouring or washing is the first mechanical process that wool goes through, to remove grease and dirt from fleece. Carbonising is unique to the woollen system and breaks down any remaining impurities after scouring.

So, actually, there are two types of method are using for scouring;

• Batch process/Discontinuous process. (by Kier Boiling/Jigger/Winch dyeing machine)
• Continuous process. (by J-Box machine)

The process removes water insoluble materials such as oils, fats, and waxes from the textile material. These impurities coat fibres and inhibit rapid wetting, absorbency and absorption of dyes and chemical solutions.

The main purpose of the scouring is to remove impurities from the textile materials. The textile materials are leave in a highly absorptive condition without undergoing any chemical or physical damage significantly. After scouring process materials become suitable for next bleaching process.

As we know singing is done to abolish the protruding fibers from the fabric surface, which will make the surface smoother and thus it facilitate the further processing which are done by the chemicals.So, if these fibers are there (if singing is not performed) it will absove the chemicals unnecessaraly as afterwards …

Conventionally,scouring is done in a hot aqueous solution of NaOH to remove hydrophobic components from the primary wall (e.g. pectin, protein and organic acids) and the cuticle (waxes and fats).

The scouring process of cotton fabric is usually carried in iron vessels called kiers. The fabric is boiled in an alkali, which makes soap with free fatty acids. A kier is normally attached, so a solution of sodium hydroxide can be boiled under pressure by excluding oxygen which reduces the cellulose of the fiber.

Sodium hydroxide

Especially hydrophobic character which is present in the fiber of fabric is removed by this process. Spot test and drop test are the method usage in industries to test the scouring effect of a scoured fabric.

Scouring is the process of preparing and washing a batch of raw sheep’s wool to remove impurities such as grease, dirt and suint. The purpose of a Condition Test is to determine the average moisture content, or regain, of batches of scoured or carbonised wool.

Wool scouring typically uses water and alkali, although scouring with an organic solvent is also possible. Scouring with alkali breaks down natural oils and surfactants and suspends impurities in the bath.

i) Saponification : It is the process in which fats are treated with caustic which leads to the formation of hydrophilic soaps. ii) Emulsification : Waxes present in the fabric cannot be removed in saponification. This molecule is made up of a water soluble (hydrophilic) and water insoluble (hydrophobic) component.

Normal washing soap is used as a emulsifying agent which makes emulsion of them. Objectives of Scouring Process: To make the fabric highly hydrophilic. To remove impurities such as oils, waxes, gum, husks as nearly as possible.

Scouring is the pretreatment process by which oil, wax, fat are removed from fabric. So that fabric weight will be reduced slightly (in case of good souring 4%-8%) and absorbency of fabric will be higher for removing of oil, wax, fat etc.

Emulsification: Wax and non saponifiable oils are removed by emulsification as they are immiscible in water. Normal washing soap is used as a emulsifying agent which makes emulsion of them. 3. The changes occurring of cotton fibers during scouring: Saponifiable oils and free fatty acids are converted into soaps.

Bleaching is the process of decolorization of raw textile material by removing inherent and or acquired coloring components from the fiber. It provides base whiteness to the textile material which could be further whitened with the help of optical brighteners or dyed | printed depending on the desired end use.

It removes all natural as well as added impurities from cotton and improves the absorbency of fabric.