Generally the liquid/solid transitions have kinetics heavily dependent of the sample thickness. For example in the case of exothermic reactions a large thickness will cause various phenomena :

•       Low heat dissipation into the environment due to a surface / volume relatively low ;
•       A thermal barrier effect, considered materials are usually poor conductors.

So if one wishes to characterize the behavior of materials used in thin layer (resins, sealants, mortar, adhesives, honey, pectins, alginates, chocolates, etc.), it is necessary to conduct tests on low material thicknesses along with accurate control of the temperature.

Therefore, in parallel with the development of Rheotech, we have designed a range of modules to control the temperature during tests in a thin layer. These tests are carried out in disposable aluminum cups, the ball bakelite being replaced by a PTFE T shape rod.

THE TEMPERATURE CONTROL MODULES

So as to cover a large range of temperatures different modules are available.

The Peltier Plate is based on the technology of the same name. It allows working from T_amb - 15°C to T_amb + 40 ° C which makes it (for example) particularly advantageous for the resins used in the building industry where the temperature of application may vary according to the season. 

The Hot Plate has a temperature range from 40°C to 250°C, to simulate the contacting of the resin with a high temperature surface (molds, press, etc.).

Currently, these modules allow to achieve isothermal tests. Simply place an aluminum cup in the module and enter a set point. After a few minutes waiting for the cup reaches the module temperature, it is possible to calibrate the gap (if necessary) and then depositing the resin in the cup and start the test. The sensor head then automatically goes down to its working position.

UPCOMING MODULES

We are currently developing an option that will create more complex temperature programs with ramps at controlled heating rate and isothermal steps.

Furthermore, other accessories and other modules are envisaged  :

•  A thermal chamber limiting the heat exchange between the material and the surrounding air; 
•  An oven allowing to have exactly the same temperature throughout the resin ;
•  A UV crosslinking module that will serve to the characterization of resins reacting when subjected to UV radiation.