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Q Is a wetting agent the same as a surfactant?
A All wetting agents are surfactants, but not all surfactants are wetting agents. Wetting agents are a class of surfactants that lower the interfacial tension of a liquid. An example is water. Water has a high interfacial tension, so a drop of water tends to “bead” on a hydrophobic surface, such as plastic.
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Q What is the function of wetting agent?
A Wetting agents that lower the surface tension of a liquid, allowing easier spreading, and that lower the interfacial tension between two liquids.
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Q Why caustic soda is used in scouring?
A Uses of caustic soda: scouring, is a chemical washing process used to remove unwanted materials from the cotton fabric. In this process, the fabric is boiled in an alkaline solution made up of caustic soda.
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Q Why is desizing essential before scouring and bleaching?
A The continuous desizing, scouring and bleaching process allows to remove the size, to degrade the waxes and natural fats which are contained in the natural cotton (scouring or alkaline boiling), and to oxidize the chromophores molecules.
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Q What is desizing and scouring?
A Desizing removes the size applied to warp yarns prior to weaving; scouring breaks down pectins and waxes and helps remove other impurities present in cotton fibres to improve water absorptivity; and bleaching commonly done with hydrogen peroxide under near boiling temperature, removes coloured impurities from fabrics .
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Q Which process is called scouring?
A 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.
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Q What is a scouring agent?
A Scouring agent is used to remove naturally derived ipurities adhering to fibers and textiles, oil and paste that adhered to fibers in the spinning process, etc. It reduces troubles in the process of dyeing and finishing. Soaping agent is used to wash out residual dye, dyeing auxiliaries, oil etc. After dyeing process.
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Q Which chemical is used for staining?
A Staining is done inorder to see the microscopic components of cell better. Different chemicals are used to stain different parts of the cell. Some of the common stains used are methylene blue, fast green, saffranin, etc.
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Q What are the 3 types of stain?
A Based on the nature of chromogen, there are three types of stain.
acidic stain (anionic stain)
basic stain (cationic stain)
neutral stain.
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Q How to remove back staining from denim?
A As far as this study is concerned, some denim trials have been taken in which we found hydrogen peroxide to be a good substitute as an anti back staining agent. It has to be used in low concentrations to avoid imparting a more bleaching effect on the garment.
