Lather factor

Titrate (1) against (2) and dilute (1) with 80% ethanol until 1 mL of the resulting solution is equivalent to 1 mL of (2) after making allowance for the lather factor (the amount of standard soap solution required to produce a permanent lather in 50 mL of distilled water). One mL of the adjusted solution after subtracting the lather factor is equivalent to 1 mg of CaCO. See also Soap solution. Cobalticyanide paper (Rinnmann s test for Zn). Dissolve 4 g of K3Co(CN)g and 1 g of KCIO in 100 mL of water. Soak filter paper in solution and dry at 100°C. Apply drop of zinc solution and burn in an evaporating dish. A green disk is obtained if zinc is present. 

Soap Titration The fact that sufficient soap solution has to be added to precipitate all the hardness causing ions from a hard water sample before lather is formed is utilized in the determination of hardness. A. suitable aliquot of the hard water sample is taken in a stoppered flask and after successive additions of a soap solution (previously standardised by titration against standard hard water) from a burette, the mixture is vigorously shaken. The stage where the lather formed persists for 2-3 minutes is taken as the end-point of the titration. The hardness of the water sample is equivalent to the volume of the soap solution used minus lather factor (volume of soap solution used to produce lather with a volume of distilled water equal to the aliquot of the hard water sample). 

In formulating shampoos and conditioners to provide the above benefits, several unique factors must be considered. The products must act quickly, of the order of minutes, and at relatively low temperatures between 20 and 40°C. The viscosity of the formulations must also be sufficiently high to avoid runoff from the hand while still spreading easily on the hair. In addition, a shampoo must generate a rich and stable lather that can be rinsed easily. Finally, since shampoos and conditioners will be used in contact with skin and eyes, they must exhibit low toxicity and irritation. 

Degradation Studies. Some laboratory studies on enhanced biodegradation have involved use of gas chromatographic analyses while lather studies have included measurement of CO2 resulting from C-labeled pesticide degradation to assess the severity of the problem, delineate the impact of environmental factors, or determine cross-adaptation Qi)- In our soil... 

Questions regarding the removal of sebaceous soil and other soils from hair are fundamental to the action of shampoos however, another fundamental question is Which is more important to the sale of shampoos—the actual abilities of different shampoos to remove soil from hair or factors relevant to the perception of cleaning such as lather, viscosity, and fragrance Laboratory or in vitro tests are critical to provide an understanding of shampoo behavior. However, subjective tests are ultimately involved to evaluate the consumer s response to the total product. The next section describes some of the more common subjective tests used in shampoo development and raises some important questions. 

The ease and rapidness of foam rinsing (i.e., without spending too much time or using too much water) could be a key factor in some countries. A foam which does not rinse out quickly could mean, to users, that product residues are left on the skin and could be perceived as a noncleaned skin-feel. Consumers generally expect a rich, creamy lather from a shower gel. The foam feel while rubbing onto the skin dictates, to a certain extent, the skin-feel performance perception during and after use. 

When Na LED3A was added to a commercial baby shampoo (Fig. 6), the lather stability was enhanced nearly sevenfold in soft water and in water containing 200 ppm water hardness. The two factors which lead to the formation of stable lather are low surface tension and high snrface viscosity. Since synergy in surface tension is not evident in the mixtnres, it is likely that synergistic lather enhancement is due to increase of surface viscosity and formation of more stable surface films which are... 

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