Our products in moving images

preeflow^® is a brand name powered by ViscoTec Pumpen- u. Dosiertechnik GmbH. ViscoTec primarily deals in systems required for conveying, dosing, applying, filling and emptying medium to high-viscosity fluids. Special service is our strength. We offer dispensing tests in our own technical rooms. And we look forward to answer your questions about microdispensing of fluids and pastes like adhesives, solder paste, thermal paste and many others.

The various fields of application include, among others, automotive, electrical and electronics industry, medical technology, aerospace, renewable energies, electrical and hybrid technology and measurement and sensor technology. The complete preeflow® portfolio can be easily integrated due to standardized interfaces. Worldwide more than 20,000 preeflow® systems are working in semi- or fully-automated dosing applications – to the user’s and customer’s complete satisfaction.

The endless piston principle

All dosing and filling units of the company are based on the endless piston principle which belongs to the group of rotary positive displacement pumps. The functionality is comparable to an endless piston that feeds the product from the suction side to the pressure side and builds up a pressure difference in doing so. The core element of each application is a volumetric dispensing pump. The interaction of an eccentrically moving rotor into a corresponding stator results into a similar flow and dosing characteristics of an endless moving piston.

Advantages of the endless piston principle

The rotor / stator geometry ensures that a constant volume is always flowing proportionally to the rotation angle per revolution. So the volume is exactly defined by the angle of rotation of the rotor. The flow direction is reversible by changing the direction of rotation, the pump curve is pressure stable and absolutely linear. This enables you to get a clear overview about the ratio between revolution, time and volume rate. This results in a guaranteed dosing accuracy of 1% at the pump outlet (depending on the fluid) which often is much lower in practice. One further benefit is the emerging dosing chamber. Its volume is absolutely constant during the motion, which gives the possibility to dispense solid-containing fluids and even extremely shear-sensitive chunky products. And in over 95% of all applications there is no need for any filling and dosage valves at all, since a short reverse motion at the end of the dosing process break the thread off and therefore prevents dripping.