Compression-relaxation-traction test also known as CRT is used to determine the elasticity, the consistency and the stickiness of soft sample. Knowing theses parameters, it becomes possible to determine the firmness, the cohesion and the threading nature of the products.
For this test, 4 samples of different hair gel from the same manufacturer are tested: a wet effect one, an extra strong one, a concrete one and a hard one. Hair gel is put in a cup and, with the use of the TX-700; the spherical probe can characterize the product. The three-step process is conduct with an 8 mm compression step at 1 mm/s which characterize the consistency. Next, there is a 10 sec relaxation step characterizing the elasticity. The final traction test which characterizes the stickiness takes place at speed of 1mm/s.
This CRT test allows us to characterize various parameters in a lot of products. Doing that, we are able to compare products from the same manufacturer.
The maximal strength (Fmax) can be correlated to the consistency of the product. The minimal strength (Fmin) can be linked to the stickiness.
The percentage of relaxation, which is inversely proportional to the product elasticity, is also determined by the device.
In this test, two gels (blue curve and green curve) from different brands linked to the same manufacturer present very close parameters. Using those data, we can determine that those gels have very close formulation.
Thanks to the TX-700, the characterization of various cosmetic products such as hair gel becomes very precise and intuitive.