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| Online Viscometer
Reliable viscosity measurement
The Online Viscometer was developed with the goal of achieving
measurements which are comparable with laboratory results and to
provide a system which provides these accurate values permanently
and without influencing the process.
The viscometer is fitted between two flange connections. The melt
channel can be designed according to the customer´s specifications
between D = 20 mm (0.8 inches) and D = 110 mm (4.3 inches). The
unit includes the pump drive, the pump, pressure transducers,
temperature sensors and the control and evaluation electronics.
Electric or liquid/vapor heating is available (optional). The setting of
process parameters, the evaluation and the display is realized via a
user-friendly touch screen panel or alternatively can be integrated
into an existing control system.
An easily exchangeable capillary permits the adaptation of the measuring device to different viscosities
ranging from 1 mPas (0.01 poise) up to 20.000 Pas (200,000 poise). A subsequent change of the
measuring range is also possible.
Due to the special melt channel design and precise fabrication, dead spots or edges in which shear- and
temperature sensitive polymers could possibly stagnate can be avoided. The very short dwell time also
prevents accumulations of degraded material. A further innovative feature is the possibility of completely
cleaning all parts in contact with the melt without interrupting or disturbing the production process.
By means of a high precision metering gear pump, a small part of the polymer melt (max. 3 kg / h or 7 lbs / h) is
separated from the main melt channel. This is pumped through a precisely manufactured slot capillary. The
inlet and outlet pressures or the elastic properties which disturb the measurement are filtered out by means of
length – optimized inlet and outlet zones in the capillaries for levelling out the laminar flow.
- No measurable temperature increase in the
rheometer thanks to ample flow channels.
- Short dwell time, no dead spots, no remains
in the melt channels.
- Through measurement in the rectangular
capillary cross section – no elastic properties
- Very compact design, flexible adaptation
to the existing melt pipe or extrusion line.
- Fast adaptation and change of the measuring
range through an exchangeable capillary plate.
- Polymer bypass, therefore no melt losses.
- High-precision measurement of the melt
temperature directly during the viscosity
- High measurement accuracy through use of
special high-precision pressure transducers.
- Complete cleaning of all surfaces and channels
in contact with the melt without interruption or
shutting down of the production process.