ORIFICE SIZE AND PROPELLANT/CONCENTRATE RATIO 663 The propellant composition underwent the greatest change with the smallest valve body orifice and the least change with the largest body orifice. As can be seen in the table, the Propellant 12/114 composition went from the original 50:50 ratio to 22:78 with the 0.016-in. body ori- fice, to 30:70 with the 0.020-in. valve body orifice, and to 37:63 with the 0.025-in. body orifice. In other words, propellant fractionation was least when the ratio of valve body orifice to vapor tap orifice was greatest. Similarly, the alcohol content in the total product increased the most with the smallest valve body orifice and least with the largest body orifice. In Systems II and III, where Propellant 12 is used alone with ethyl alcohol, considerable fractionation occurred because of the large differ- ence in boiling points. Propellant 12 boils at --21.6øC, while ethyl alcohol boils at 78øC. In System II, which originally contained 25% Propellant 12, the propellant concentration dropped to 1% with the smallest body orifice, after 75% of the product had been discharged. Changing the ratio of valve body orifice to vapor tap orifice from 0.8:1 to 1:1 netted only a 1% gain in propellant concentration after dispensing 75% of the prod- uct. However, 12% of the propellant remained at 75% empty with the 0.025-in. body valve orifice. Thus, less change occurs in the propel- lant/concentrate ratio with a larger valve body orifice and a larger ratio of valve body orifice to vapor tap orifice. The results of the tests with Systems II and III are shown in Table II Similar results were obtained with System III which contained 38% Propellant 12 in the original product. While the propellant loss was Table II Composition of Liquid Phase after Discharging 75% of Product (Systems II a and IIIb--Propellant 12/Ethyl Alcohol) Valve: Stem: 0.018 in. Vapor tap: 0.020 in. Body orifice: As indicated Body orifice, in. 0. 016 0. 020 0. 025 Wt % Liquid System II Components Propellant 12 1 2 12 Ethyl alcohol 99 98 88 System III Components Propellant 12 16 20 27 Ethyl alcohol 84 80 73 75%, by wt, anhydrous ethyl alcohol 25%, by wt, Propellant 12. 62 %, by wt, anhydrous ethyl alcohol 38 %, by wt, Propellant 12.

664 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS not as drastic with System III as with System II, the pattern was the same. More propellant was lost with the smaller valve body orifice and less with the larger orifice. Hair Sprays The two formulations for hair sprays used were: • Systbm IV, 50.% •anhydrous ethyl alcohol and 50% Propellant 12/11 System V, 50% anhydrous ethyl alcohol and 50% Propellant Fractionation aga'in occurred because of differences in boiling points. In' Syõtem 'IV, pre'fe'•eii'tial' fractionation of Propellant 12 occurred be- causb of its low boiling point','--21.6øC as noted previously. Some frac- tionation of Propellant II occurred because its boiling point of 74.7øC is near room temperature. The higher boiling ethyl alcohol (bp 78øC) did not fractionate. Table III illustrates the results of the tests on Sys- tem'IV. Table III Composition of Liquid Phase after Discharging 75% of Product (System IVa--Propellant 12/11/Ethyl Alcohol) Valve: Stem: 0.018 in. Vapor tap: 0.020 in. Body orifice: As indicated Component Propellant 12 Propellant 11 Ethyl alcohol Propellant Ratio Propellant 12 Propellant 11 Body orifice, in. 0.016 0.020 0.025 Wt % Liquid 4.5 7.0 10.2 28.3 26.5 25.0 67.2 66.5 64.8 14 21 29 86 79 71 "50%, by wt, anhydrous ethyl alcohol 50%, by wt, Propellant 12/11 (50: 50). With System V, the changes in composition with the 0.016- and 0.020-in. valve body orifices were about the same as for System IV. The small differences were probably caused by the presence of isobutane in Propellant A. However, with the 0.025-in. valve body orifice, there is * ( enetron© fluorocarbon Propcllant 11, Allied Chemical Corp., Morristown, N.J. t Propellant A consists of 45% Propellan! 12, 45% Propellant 11, and 10% isobutane.