2008 TRI/PRINCETON CONFERENCE 141 Table III The Effect of Texturizing Treatment on Apparent Stiffness of Air Dried Virgin Hair Tress No. of passes 1 2 3 4 5 Apparent stiffness (g-force mm) 3300 2400 2100 1850 1790 Table IV The Effect of Texturizing Treatment on Blow Dried Virgin Hair Tress Stiffness (g-force mm) Friction coeffi cient Control 1120 ± 30 1.5 ± 0.1 Texturizing treatment 1400 ± 100 1.4 ± 0.2 carried out only in the rotational mode. The fi rst pass produces the highest apparent stiff- ness, which gradually decreases with each subsequent pass through the test assembly. Table III illustrates how one can quantify the effectiveness of texturizing treatment and its persistence. Table IV shows the changes to hair stiffness and the apparent friction coeffi cient of blow dried hair samples treated with texturizing gel. The Aqualon SLT accurately detects the increase in hair stiffness. The treatment, however, did not affect the apparent friction coeffi cient. The difference in the apparent friction coeffi cients in Table I and Table IV is due to the difference in the batches of hair used. The results shown in Tables I and II were collected using “special quality” hair in which damaged hair is excluded. The tresses used in the subsequent work were regular quality hence the higher apparent surface roughness and the higher apparent friction coeffi cient. CONCLUSIONS Aqualon SLT measures apparent hair tress stiffness, friction and apparent friction coeffi - cient. We demonstrated that the measured parameters correlate with changes expected from hair treatment—both chemical, i.e. bleached, and topical, i.e. treatment with con- ditioner or texturizing gel. The simplicity of the operation, effi ciency and precision of the device make it a useful addition to any hair application laboratory. REFERENCES (1) W. Newman, G. L. Cohen, and C. Hayes, A quantitative characterization of combing force, J. Soc. Cos- met. Chem., 24, 773–782 (1973). (2) Y. K. Kamath and H.-D. Weigmann, Measurement of combing forces, J. Soc. Cosmet. Chem., 37, 111– 124 (1986). (3) P. S. Hough, J. E. Huey, and W. S. Togyesi, Hair body, J. Soc. Cosmet. Chem., 27, 571–578 (1979). (4) C. R. Robbins in Chemical and Physical Behavior of Human Hair, 4th ed., p. 413. (5) L. J. Wolfram and L. J., Albrecht, J. Soc. Cosmet. Chem., 36, 87 (1985). (6) U. Assmus, P. Augustin, H. Hensen, P. Hossel, G. Lang, H. Leidreiter, A. Markowetz, V. Martin, B. Noecker, E. Poppe, M. Pfaffernoschke, H. Schmidt-Lewerkuhne, E. Schulze-zur-Wiesche, A. Schwan- Jonczyk, J. Wood, and F.-J. Wortmann, Determination of the feel of hair after cosmetic treatment— Sensory and objective test methods, IFSCC, 11, 121–128 (2008).

J. Cosmet. Sci., 60, 143–151 (March/April 2009) 143 Hair breakage—How to measure and counteract HANS-MARTIN HAAKE, SANDRA MARTEN, WERNER SEIPEL, and WOLF EISFELD, Cognis GmbH, Henkelstr. 67, 40551 Düsseldorf, Germany. Synopsis A system to determine the effi cacy of hair treatments in terms of anti-breakage and split end prevention was developed which involves the repeated combing of hair strands. The device allows ten hair strands to be combed simultaneously. First, the infl uences of chemical hair treatments like bleaching on hair breakage were examined. In a next step, the protective effects of benchmark products from the market were studied. Since nearly all commercial products with anti-breakage claims contain silicones combined with cationic polymers, alternative actives were searched. In a test series with different waxes in shampoo formulations with a variable number of parameters, the particle size was found to be the factor with the strongest infl uence on the amount of wax deposited on the shampooed hair. Therefore, a targeted development was started, resulting in a com- bination of several ethers dispersed in sodium laureth sulfate. Excellent conditioning, anti-breakage and split ends protection properties of the compound were found, showing also a dosage dependency. The latter could be explained by analyzing the amounts of waxes applied on treated hair. In these experiments, a dependency on the concentration in the shampoo was found. INTRODUCTION Anti-hair breakage is one of the most popular claims made for modern shampoos and conditioners. Nearly any brand offers anti-breakage or anti-damage shampoos and condi- tioners, or even some other products like masks. Literature describes several methods to test anti-breakage properties. The most laborious way reported was an in-vivo determination of broken hair fi bers gathered from 15 panel- ists (1). Hair breakage was also tested, applying a tensile strength protocol (2), which may be questioned since the force to pull out hair from the bulb is signifi cantly smaller than the break forces (3) and also depends on the phase of the growth cycle of each hair. Another means to determine the anti-breakage properties of cosmetic products is a re- petitive combing of treated hair strands (4–6). We developed a set-up for such a testing protocol, allowing for an automated parallel combing of up to 10 hair strands. Broken hair fi bers are collected in separated drawers for each strand. Besides hair breakage, the generation of split ends can also be observed and quantifi ed. Address all correspondence to Hans-Martin Haake.