Lipsticks - Wire Cutting Method
stiffness , firmness
The firmness, smoothness, brittleness, and payout of lipsticks are important characteristics for consumer expectations. The lipstick firmness will have a direct correlation with payout. Lipsticks that are too firm may also be brittle and may break in their cartridges. Controlling these textural parameters is also critical for producing consistent lipsticks with new formulations, brand extensions, process changes, and packaging changes. Furthermore, it is more cost effective to monitor textural characteristics with instrumentation rather than consumer panels. Testing was done on six brands of lipstick with three different fixtures. A wire cutter (TA-26) and craft knife (TA-44) were used to cut through the lipstick. A 2 mm diameter puncture probe (TA-52) was used to penetrate into the lipstick.