1 / 19

5- WASHING CHEMICALS

This chapter provides an overview of washing chemicals and detergents, including their definition, composition, and properties. It covers surfactants, builders, whitening systems, additives, softeners, and finishing products. Learn about the different types of chemicals used in detergents and their functions.

deen
Download Presentation

5- WASHING CHEMICALS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 5- WASHING CHEMICALS Chapter 5 summary Enter

  2. DEFINITION: Substances defined as detergents are those that have the property of removing dirt from an object without damaging it. Detergents are combinations of chemical compounds which, associated with the factors of time, temperature and mechanical action, allow a surface to be freed of its dirt.

  3. CHEMICALS WASHING DETERGENTS WHITENERS SOFTENERS FINISHING PRODUCTS

  4. DETERGENTS SURFACTANTS BUILDERS ADDITIVES WHITENING SYSTEM AUXILIARY AGENTS Typical composition: Anionic surfactants Sodium tripolyphosphate Chemical whiteners Enzymes Water Non-ionic surfactants Zeolites Whitening activators Anti-redepositing agents Sodium sulphate Cationic surfactants Sodium carbonate Optical whitener Corrosion inhibitors Amphoteric surfactants Polycarboxylates De-foaming angents Perfume

  5. SURFACTANTS These are the constituents of detergents, and provide special wetting, foaming and detergent properties. They reduce the surface tension, causing water to behave in a particular fashion in the presence of solids and fats. Hydrophilic end: Diagram of a surfactant molecule: Lipophilic end

  6. SURFACTANTS Examples of use: Manual dishwasher Types of surfactants: Depending on their Ionic behaviour in aqueous solution, they are classified into 4 groups: Linen detergent for machines Anionic S. (-) Noionic S. (nil) Softener for linen Cationic S. (+) Creams, disinfectants, etc. Anphoteric S. (depending on mean pH)

  7. SURFACTANTS How do surfactants work? The soiled fabric comes into contact with the water The bath with detergent wets the fabrics and the dirt The surfactants separate the dirt from the substrate The dirt is stabilised. The hydrophilic part in contact with the bath. The lipophilic part in contact with the dirt.

  8. BUILDERS They are added to detergents to protect or improve the detersive efficiency. They add detergent properties that improve the detergent process.

  9. WHITENING SYSTEM In laundering we use the term "whiteners" to refer to the chemicals that remove the colouring dirt and keep the fabrics white. In the composition of a detergent, we can find the following:

  10. ADDITIVES Minority substances in the composition of a detergent. Their properties differ from one detergent to another: ENZYMES: These are natural proteins that enhance detergents and allow them to work at a low temperature. Each type of enzyme degrades one type of substance. ANTI-REDEPOSITING AGENTS: These keep the dirt removed from the fabrics in suspension in the bath. CORROSION INHIBITORS: These are used to protect the substrates on which the detergent acts. DE-FOAMING AGENTS: These are needed to ensure that the detergent solution possesses an optimum level of foam. PERFUME: This is added to make the product pleasant to use and to leave a residual aroma.

  11. AUXILIARYAGENTS Without a mission in the detergent process, they are necessary to ensure that detergents have a presence that aids their use and that allows their properties to be preserved. Water Auxiliary presentation agent in liquid detergents. Influences fluidity, viscosity, density, etc. Sodium sulphate A colourless and crystalline powder. It acts as an absorbent and helps to disperse all the compounds of a detergent powder evenly.

  12. An oxidising agent is a chemical element that captures electrons, ending up with a positive charge. A reducing agent is a chemical element that cedes electrons, ending up with a less positive charge than it had.

  13. Oxidising agents: These release active oxygen, which is ultimately responsible for bleaching out and removing coloured stains. In addition they possess disinfecting properties.

  14. Whitening process: Effectiveness of whiteners vs temperature 55-60ºC 60ºC 80-85ºC 20-25ºC Each type of oxidising agent has a temperature of maximum effectiveness

  15. Reducing agents: These are used in special processes. They are especially effective on synthetic colourants, and are widely used to remove colour bleeding on white articles. Their characteristic odour is due to their compounds with sulphur.

  16. SOFTENERS Softeners Washing processes end up reducing the softness and flexibility of fabrics. On washing the fibres become tangled, and on drying they do not return to their natural position, which reduces their resistance. Their main component (cationic surfactant) provides lubrication to help the fibres return to their natural position In addition, softeners contain: Perfume Preservatives Additives: colourants, optical whitening agents, disinfectants, etc. Presentation aids

  17. Properties:

  18. Finishing products: Added to the end of the detergent process, this group of products restores the treated fabrics to their initial conditions. They help to neutralise, lighten, soften and condition the linen before it is dried and ironed.

  19. END OF CHAPTER 5 SUMMARY

More Related