Removing a lipstick cap and turning its base are different actions. For a pull-off cap, opening is assessed as a force along a defined direction. Operating a twist-up mechanism is assessed as torque through rotation. A comfortable result for one action does not establish a comfortable result for the other.
Use the measurement that matches the action
A cap-removal test can record the force needed to release the closure. The grip, pulling direction, speed and starting condition affect that result. Identify whether the design actually has a pull-off cap before applying this method; another closure type needs its own evaluation.
A mechanism test follows torque as the base turns and the cup travels. The effort to start movement can differ from the effort to keep it moving. Mecmesin's published lipstick case study describes both cap-removal force and torque-versus-angle testing, including starting and running measurements.
Sample display room. This background view does not establish a component structure, test result or customer endorsement.
Control the fixture before judging the package
A fixture must hold the intended fixed and moving parts without slipping or distorting the tube. Squeezing a thin shell or adding unintended side loads can change the result. Record the setup so that a later comparison measures the same action rather than a different way of gripping it.
Force and torque have different units and cannot be added into one meaningful mechanical value. They can appear in the same approval report, but each needs its own method and acceptance decision.
Keep separate measurements within one assembly review
The two functions use different interfaces, yet they belong to the same assembled pack. A material, decoration or assembly change may affect more than one function. Retest affected properties rather than claiming that improving the cap cannot influence the rest of the tube.
Compare relevant empty and filled samples and agreed conditions. Check raising, retracting and product support as required for the design. Low running torque alone does not prove that the lipstick will retract during application; resistance to that load is a separate observation.
SamBound New Material Technology Company Ltd. describes its empty packaging offer at sambound.com. The project specification should identify the cap, mechanism, decoration and tested conditions. Establish limits from the intended handling and evidence; do not present a supplier profile or a generic number as proof that both actions have passed.
sambound.com
SamBound New Material Technology Company Ltd.
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