Dosing of abrasive thermal pastes in cyclic operation
The ultimate stress test for stator materials
In dosing technology, thermal pastes put very high demands on the dosing systems because the fillers tend to form sediment and on the other hand are highly aggressive to the dispensing unit. Therefore two parameters are essential: Firstly, the level of pressure has to remain as consistent as possible during the dispensing process to prevent separation between filler and binder and, secondly, the right choice of materials in the design of the dosing components for abrasive media has to be made.
In this context, a highly aggressive thermal paste has been tested at ViscoTec’s technical centre. In 1,500 dispensing cycles and 80 hours of operation, more than a ton of gap filler was dispensed with ViscoTec’s eccentric screw pump. The supply of the medium was determined using the barrel emptying system ViscoMT-L from a 200 litre barrel. The 160 ml dosing shots were dispensed with the positive displacement pump 3VMP22. To further increase the load of the stator, the dosing pressure was kept constant at 20 bar. Two mechanical highly resistant elastomeric mixtures from the ViscoTec stator portfolio were tested.
The wear and tear of the stator was evaluated based on the dimensional deviation before and after the trial. This resulted in an average deviation of 0.45 %, which exceeded the expectations of the material manufacturer. By using the eccentric screw pump from ViscoTec, the end user benefits from an extended service life of the dosing components - which in turn contributes to improved energy efficiency and a reduction in maintenance and repair costs.
ViscoTec Pumpen- u. Dosiertechnik GmbH
ViscoTec Pumpen- u. Dosiertechnik GmbH primarily deals with systems required for conveying, dosing, applying, filling and emptying medium to high-viscosity fluids. The technological leader headquarter is in Töging a. Inn (Bavaria). Furthermore ViscoTec has subsidiaries in the USA, in China and in Singapore and employs more than 120 people worldwide. Numerous sales partners all over the world complete the international distribution network. Next to technically sophisticated solutions to even the most complicated application, ViscoTec is the single point of contact to deliver all components for a complete system: from emptying to preparing and to dosing. This guarantees successful interaction of all components. All fluids showing a viscosity of up to 7.000.000 mPas can be conveyed and dosed almost pulsation-free and with extremely low shear. ViscoTec offers comprehensive consulting for every application and, if required, extensive tests will be carried out in close cooperation with the customer. The dosing pumps and systems are perfectly adapted to their respective application whether it is the food sector, the automotive industry, the aerospace field, the medical technology, the pharmaceutical industry and many other branches.