}14 JOURNAL OF TtlE SOCIETY OF COSMETIC CHEMISTS points of intersection on the outer layer of the mass of hair fibers where bridges may be formed, and definite holding may be expected. With a heavy wet spray, similar to the case in which the hair fiber is saturated with alcoholic concentrate, much broader connecting links and, there- fore, ,greater holding may be expected but the connecting links are Figure 7. Long spraying with wet spray (note complete wetting of hair shaft by hair spray) Figure 8. Formation of bonds or bridges between adjacent or intersecting hair fiber only effective where hair fibers cross or are adjacent. However, the strength of the holding is dependent upon the much higher area of contact between the resin and the hair junctions. A pp•ico, iion Effect, Since alcohol wets hair very easily, it seems reasonable that a water- set tress might easily relax if saturated with hair spray. In order to confirm this, two groups of hair tresses were set in water pin curls, al- lowed to dry, unpinned, and their length measured in inches. The tresses were then sprayed with the respective sprays for a three-second period at a distance of 10 in. Tresses were again measured after drying. The results of this experiment are tabulated in Table III. It may be

THE ACTION OF HAIl( SPRAYS ON HAll( 315 seen that the A variable, the B variable, and the interactions of AB are significantly different. Although no rankings were determined, the data permit the conclusion that a wet spray tends to change or relax the initial water wave. Another experiment was performed in order to determine the relative relaxation of water-set tresses after immersion in water, in 75% eth- anol, in {, 5% ethanol, and in anhydrous ethanol. Tresses of hair were set with water, wound on peg boards and dried. After unwinding, groups of six dried tresses were immersed in water and in each of the ethanol/' water solutions. Length measurements were made after distinct periods 10½ 8oe • •c • 40 • oeo• o ffWATER 20 40 60 80 IO0 120 TIME IN SECONDS Figure 9. The effect of ethanol/water mixtures on curl retention of wound tresses of immersion. Figure 9 summarizes the results of the experiment. It may be observed that tresses wet with water relax very rapidly, whereas the other groups of tresses relax according to the amount of water present in solution. SUMMARY The mechanism of hair holding by hair spray differs depending upon the size and distribution of liquid droplets impinging upon hair fibers and is a function of the wetting of the fiber by the liquid vehicle. The application of a hair spray and its effect depends upon the wetness of the hair spray and the degree at which curls relax. The hypothesis is made that the relaxation of a hair tress after being sprayed with a hair spray depends upon the amount of moisture in the form of water vapor from air absorbed during the application of the hair spray. (Received September 14, 1fi64)