Pouches, liquid detergent

The initial popularity of tablets led to the logical question as to whether liquid detergents could be made available in a unit dose form. The resolution came with the development of a polymer pouch using polyvinyl alcohol (PVOH) as the container (Figure 19.4). 

Water soluble polymers are also now finding application in the area of packaging. For example polyvinyl alcohol pouches are used to dispense liquid detergent formulations. The pouch is placed in the washing machine and the polyvinyl alcohol slowly dissolves to release the liquid. The emphasis nowadays is to use natural polymers, both polysaccharides and proteins, as packing materials because of their ability to biodegrade and recent advances in this area are covered in Chapter 10. 

These many new forms have afforded researchers with vehicles to have improved chemistries and to offer multiple benefits. Additionally, for added convenience, many of the product types can be purchased in unit dose form. Unitized doses of dishwashing detergents are more attractive because they alleviate the need for precise dosing and avoid wasteful overdosing. Packaging materials have been developed such that one dose could have several layers or compartments that break down and dissolve over the wash or with specific triggers. " Sharma et al., for example, discuss a multicomponent pouch that can deliver a powder form on one side and liquid/gel form on the other side. Some of these newer product forms with their reported benefits can be seen in Figure 3.8. 

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