From the testing of packaging to absolutely any solid material used in cosmetic products, it is essential to ensure that the strength and quality of the material is up to the job.
With lipstick, obtaining the correct shear force is vital if the product is going to be used effectively and not end up an unusable blob or a broken stick after a couple of applications.
Lloyd Instruments has adapted its LFPlus materials testing equipment to the exacting requirements of lipstick manufacturers based in France, by designing a special grip to hold the lipstick in the correct position for the procedure.
"Lloyd Instruments conducts a variety of tests for a number of industries," said Carl Bramley, Lloyd Instruments export manager. "The approach to testing for the cosmetics industry is very similar to that of food as the safety and consumer requirement run along the same lines.
"As with all cosmetic products, defining the correct consistency of lipstick is vital to achieve market success. If the lipstick shears off or crumbles then it will not last long on the market. When conducting our pilot testing we considered the exact use for the product in order to define what the requirements needed to be."
The company adapted the equipment in close co-operation with the French cosmetics houses. The resulting fixture is supplied in two parts and will accommodate lipsticks up to 20 mm diameter. The lower part of the fixture provides a gripping mechanism to hold the main part of the lipstick during the test, while the upper fixture is an inverted 'Y' shape and attaches directly to the loadcell.
By applying a force directly to the lipstick using this fixture, a bending action can be simulated which is equivalent to that experienced by the product when in use. The break strength can then be measured.
The fixture has a maximum capacity of 50 N and is therefore suited for use with the LFPlus single column universal materials tester, which is designed for material testing and force measurement applications up to 1 kN (225 lbf). Test speeds range from 0.05 to 1270 mm/min with an accuracy greater than 0.2 per cent. The company also says that tests can be fully automated through the addition of software.
But the company's services are not only confined to lipsticks. They can also be used to test the burst strength of cosmetic tubes and the extrusion force of cosmetic products in tubes.
As well as conducting tests on solid cosmetics products, including compacts and powders, Lloyd Instruments also provides testing and testing equipment for a wide range of cosmetic packaging materials, ensuring that the materials comply with safety standards and that they provide adequate strength to contain the products under normal use.