MELT PUMPS [EXTRU] FOR EXTRUSION

Efficient. Pulsations-free. Gentle

Robust and flexible

The robust design and wear-resistant materials make the EXTRU indispensable for extrusion. It can also be used to transport natural rubber and soft PVC through different special designs.


The WITTE fast-changing color design is perfect for master batch applications with frequently changing colors.

Melt pumps for extrusion

The extrusion gear pump is mainly used in connection with extruders or kneaders. They lower the naturally existing pulsation and uneven transportation, particularly of single-screw extruders.


The extrusion pump is also used as a melt pump. It takes over the establishment of the required transport pressure, which is needed for the downstream equipment.

Efficient pressure build-up

In the gear pump, the pressure build-up occur significantly more efficiently than in the extruder itself. The extruder is relieved through the use of an extrusion pump. Significantly less energy or heat is added to the polymer. The melt pump thereby contributes to the gentlest possible transportation. The EXTRU pump is indispensable for the production of precise foils or micro-granulate.

Request for a melt pump quotation

Please fill out the following form so we can create an offer that is exactly customized to your needs. One of our sales engineers will examine your request and contact you to discuss your personal solution.

Request for quote

Design examples for melt pumps [EXTRU]

 

Advantages:

  • Electrical heating
  • Cooled threaded shaft seal
  • Housing design
  • Double-sided drive shaft
  • Optional herringbone gearing

  • Electrical heating

    The enclosure can be heated electrically. Separate lid heating is also possible as an option.

  • Cooled threaded shaft seal

    To increase viscosity, the threaded shaft seal can be equipped with a heat sink. For particularly sensitive media, a "bleeding bearing" variant is available. Here, the bearing lubricant flow is diverted to the outside so that stressed material does not get back into the main flow.

  • Housing design

    The housing can be designed in a wide range of variants. A round and a square design are available as standard. But customised designs are also possible. A version for quick colour changes is also available as an option.

  • Double-sided drive shaft

    To prevent the drive shaft of the pump from being driven/pushed out of the housing when there is high pressure on the suction side (delivery pressure of the extruder) of the pump, the drive shaft must be relieved. It is led out of the housing on both sides and sealed so that atmospheric pressure prevails on both sides of the drive shaft. The shaft runs unloaded.

     

     

  • Optional herringbone gearing

    For particularly sensitive media, we offer a special toothing for the EXTRU melt pumps. The herringbone gearing reduces the natural pulsation of the extruder and guarantees a constant melt flow.

Melt pump EXTRU III made by WITTE

 

Technical data

Housing
Heat-resistant carbon steel, for example, 1.6582 · Stainless steel 1.4313 · optional with coating · optional with coating
Gear Shafts
Tool steel · Nitriding steel · Special steel · optional with coating · Helical gearing · Herringbone gearing (for transportation with very low pulsation)
Shaft seals
Threaded shaft seal · Stuffing box
Heating
Electric through heating cartridges · Cover heating optional
Friction bearing
Tool steel · NiAG (nickel-silver) · Aluminum bronze · Special materials · optional with coating

Operating parameters

Viscosity
Up to 40.000.000 mPas
Temperature
Up to 400°C
Suction pressure
Vacuum up to max. 120 bar
Transport pressure / differential pressure
Up to 250 bar. Special designs also for higher differential pressures
Pump sizes
From 4,7-22-22 (4,7 cm3/U – 10 kg/h) to 12.000-280-280 (12.000 ccm/U). Sizes with smaller gears for higher differential pressures are possible, p.e. 690-140-90.

Application examples for WITTE melt pumps from the EXTRU series

Plastics
PS · PET · PVC · PC · PMMA · HDPE · LDPE · LLDPE · PP · PEEK · POLYSULFONS · LICORICE · CHEWING GUM

Mounting positions EXTRU melt pumps

The melt pumps of the EXTRU series are very flexible in terms of installation. They can be installed in almost all installation positions, even if there is only limited space available. The flexible arrangement of the individual components makes it possible to optimally utilize even tight spaces.

Melt pump on mobile carriage with angular gear and 90 ° angled motor (vertical upwards)
Melt pump on mobile carriage
Melt pump on mobile carriage
Melt pump with cardan shaft, gearbox and motor in vertical row installation

A variety of variants are possible, for example:

  • Melt pump on mobile cart with angular gear and 90 ° angled motor (vertically upwards)

  • Melting pump with cardan shaft, gearbox and motor in vertical line installation

  • Melting pump with cardan shaft, gearbox and motor in horizontal line installation

  • Melt pump on mobile cart with angular gear and 90 ° angled motor (pump vertically upwards)

  • Various other installation options

 

Seal variations for melt pumps


References melt pumps

Melt pump in angular design with special flange
Melt pump extrusion pump round design
Melt pump in round design on a base frame
Melt pump on mobile cart
Melt pump for ABS filament production
Melt pumps with customized adapter plate
Melt pump for the production of 3D printing HDPE filament .
Melt pumps for the production of polypropylene
Melt pump for the production of medical tubing using the extrusion process.