IIIII I IIIII I Untreated hair Chemical treatment of the Treatment with a Removal of treatment after shampooing whole tress rinsing with conditioner through frame combing combing measurement water and shampooing windows in a frame measurement before (1) combing measurement. and rinsing. and after shampooing. (2) (3) (4) Figure 3. Experimental protocol of procedure B. 150 100 .......... so 0 0 50 100 150 200 250 300 350 Distance [% of initial] .... before treatment after treatment after treatment + shampooing Figure 4. Combing curves of virgin, dark brown hair treated according to procedure B (no chemical treatment) after exposure to 0.2% polyquaternium-11.

SPATIALLY RESOLVED COMBING ANALYSIS 97 500 300 200 100 1st treatment 2nd treatment ......... ii ..... _s• ............... _••_ .... 284 -I-7 ....... 306d=35 29o, 4-36 Untreated After 1st After 2nd After 3rd After 4th Hair Shamp. Shamp. Shamp. Shamp. Figure 5. Fhe combing work of virgin, dark brown hair after one, two, and three treatments with 0.2% polyquaternium-1 1 followed by shampooing. oughly rinsed before experimentation. For nonviscous treatment products, the fibers were immersed in their solution for a specified amount of time, followed by rinsing with water. For viscous creams, a spatula was employed to ensure a uniform distribution of a product in hair, and the treatment was followed by prolonged rinsing with water to remove any formulation residues. Hair tresses were prepared by gluing 2-g fibers to 1.5 x 1.5-in plastic tabs with Duco cement. The length and width of a hair tress was 6.5 in and 1.25 in, respectively. Solutions of polyquaternium-11. The conditioning treatments were prepared as 1% polyquaternium-11 (Gafquat 755N, International Specialty Products) solutions (0.2% active). They were applied to hair samples for two minutes by saturating the exposed sections of fibers in the excess of polymer solution, followed by extensive rinsing with water. Bleaching. Hair was bleached by using a powder lightener based on ammonium persul- fate/potassium persulfate blended with 20 volume hydrogen peroxide. The paste was applied to hair in the window area for 60 minutes, followed by extensive rinsing with water and shampooing with 3% ammonium lauryl sulfate. Perming. Hair perming was performed by using a formulation based on ammonium thioglycolate with 2% hydrogen peroxide as a neutralizer. In order to test the condi- tioning properties of polyquaternium-11, a neutralizer lotion containing 0.2% active