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melt pumps


Melt-pumps for extrusion and compounding

melt-pumps eproteceprotec's melt-pumps (extrusion pumps, metering pumps or gear pumps) are installed in all applications in extrusion and compounding of plastics. Melt pumps are used to build up constant pressure and ensure constant output. The extruder screw is relieved, this enables a higher output power and increases the flexibility in different applications. Smooth, efficient and constant pumping of plastic melt through extrusion-die guarantees constant product quality and dimension. eprotec also offers its melt pumps together with a drive unit and controller.

Retrofitting of extrusion-lines with melt-pumps leads primarily to a constant throughput. This is a requirement for dimension stability of extruded product. Retrofitting with melt-pumps leads mostly to higher output of extrusion-line. When a melt-pump is installed in extrusion-line the screw is not anymore responsible for the full pressure build-up.


Specifically designed for application:

eprotec melt-pumps are designed precisely for every application. According viscosity, throughput, processing temperature the pump-size, surface coating, tolerances e.g. are determined. Type and amount of fillers determine specific surface coating and bearing materials.



Ersatzteile Schmelzepumpen rumpenreparatur rumpenreparatur rund
 spare parts  repaired  upgraded

Spare-parts for most of all existing melt-pumps regardless who original supplier was:

Main parts of melt-pumps are pump body, gears, bearings, special shaft seals and side covers. These are the spare-parts eprotec offers for nearly all existing pumps in the market. No matter who the original supplier was. These spare-parts are delivered cost-effectively and quickly.


Repairs of melt pumps:

The same know-how as for new pumps is also available for the repair and upgrade of existing melt pumps.

eprotec offers repairs for almost all melt pumps on the market.

Even very old melt pumps (round design) can be upgraded -> as good as new!


melt pumps eprotec


 Sizes and capacitiy range of eprotec melt-pumps for extrusion

Polymer   melt-X 1 melt-X 2 melt-X 4 melt-X 7 melt-X 10 melt-X 20 melt-X 40 melt-X 80
V (cm³/upm)   22,5 45,2 90 175,9 364 706  1463 3140
HDPE   105 180 300 500 830 1400 2400 6300
LDPE   140 240 400 700   1300 2200 3800 7500
PP   160 260 480  850   1500 2400 3900 8000
PS/ABS   200 320  570 1100 1900 3100 4900 10000
PET    220 350 600 1200 2100 3400 5400 12000
   approximate data, according to density and processability


eprotec melt pumps

Important properties: 

Optimized melt-flow channel according experience in extrusion of plastic melt

Threads for pressure sensor are located in pump-body

Small melt channels for reduced residence time !

Heating cartridges with zones of different heating capacity (less energy in melt channel area)

These and more you find in file "important properties" in download area,

Control units:

are available with different options.


 Steuerung Schmelzepumpe Extrusion    Steuerung Schmelzepumpe Compoundieren
 extrusion mode    compounding mode

Please see also site for spare parts.

melt pumps

Melt-pumps for Extrusion and Compounding

There is a blacksmith for pumps as well as for ideas in high-end extrusion technology, manufacturing melt-pumps for different applications.

Pumpwerkstrasse (German word for “Pump Factory Street”) is the right address of eprotec in Zürich/Regensdorf Switzerland. Since last century there were developed and manufactured pumps. High precise melt-pumps for extrusion and compounding designed with know-how, experience and as well designed exactly according application.

Melt-pumps are standard in extrusion-lines for long time, especially for sheet extrusion as well as in compounding. The generation melt-X is eprotec’s all-round talent. With all its modifications it is design-able exactly according application for film- and sheet-extrusion as well as for compounding.

Melt-pumps care for constant output

Melt-pump melt-X minimizes pressure variations in extrusion-lines, which are mainly caused by feeding fluctuations in extruder itself.

Melt-X cares for constant throughput; it relieves the extruder-screw from pressure built up by tooling unit and enhances the output of extrusion-lines.

Years of experience in extrusion and pump-designing are background of eprotec’s staff. Manufacturing partners produces the pumps resp. the parts - especially designed according its application - with state of the art tooling machines.

Designed according its application

eprotec’s pumps are always design according customers application (never taken out of a shelf). These melt-pumps are designed according processed polymer as well as according properties and amount of fillers.

Know-how in tooling-materials, in right gap dimensions in the combination of shafts, bearings and shaft seals allows the use eprotec’s pumps even with aggressive and abrasive fillers as well as processing thermally unstable polymer melts such as PVC.

Experience with fillers like glass-fibre, barium sulphate (BaSO4) and chalk (CaCO3) leads to extensive know-how in tooling-materials and design.

Correct selection of tooling-material

High-tech tooling materials are used in the modular designed eprotec’s melt-pumps melt-X.

Special coatings are responsible for long lifetime of melt-pumps even if corrosive and aggressive as well as highly filled melts are processed.

The teeth of the shafts in the melt-X extrusion pumps are manufactured in a way that full nitration-depth are provided (developed for no grinding after nitration),

Heating with know-how

Also the heating cartridges are designed especially for the use in extrusion pumps. Less energy input near the melt-channel reduces thermal degradation in extrusion-process.

Optimized for melt-flow.

Melt channels are designed for high flow-speed and short residence time in eprotec’s extrusion pump melt-X.

The bearings are lubricated with the polymer. Small part of processed polymer is guided from high-pressure side through bearings to low-pressure side.

Pressures sensors in melt-pump’s body

The holes for the pressure probes are located in the body of eprotec’s extrusion melt-pump. They are located in the even part of the melt-flow optimized channel. No steps in the channel are created where melt could stick.

Rework of extrusion melt-pumps

Same know-how is available for repairing existing melt-pumps. Spare-parts for most melt-pumps in the market are available, no matter who origin supplier was.

Melt-pumps are standard in extrusion of high quality products; melt-X with its outstanding properties is the ideal tool for daily use with standard material, frequent material changings as well as in high-performance extrusion with high speed extruders.

 Kreyenborg Infrared Dryer - thickness gauges - automatic systems for extrusion-dies - electrostatic discharging