Hair Lotions

Laboratory Viscometer Application Data Sheet

USE

Lotions are applied to the hair for various reasons such as color, body and appearance.

ISSUE

Lotions produce highly variable testing results from operator to operator. Duplicating readings of this nature can be very time-consuming, however, the R/S+SST and a 40-50 second yield stress test greatly improves reproducibility and reduces total test time.

Test Equipment:

• Instrument: R/S+SST Rheometer (Soft Solids Tester)
• Geometry: V80-40, V40-20 Vane Spindles
• Software: RHEO2000

TEST METHOD

Controlled by Shear Rate (CSR)

PROGRAM

• One step,
• Start RPM = 0.8
• End RPM = 0.8
• Time = 40-50 seconds
• Plot = Torque (mNm) or Shear Stress on Y1, Time on X, no Y2

The data in the above graph shows that the measured torque values climb to a maximum and then "plateaus" or begins to decrease. By establishing pass/fail limits, the lotion under evaluation can easily be certified for acceptability by this quick QC test.