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.
Design examples for melt pumps [EXTRU]
- 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
- Electric through heating cartridges · Cover heating optional
- Friction bearing
- Tool steel · NiAG (nickel-silver) · Aluminum bronze · Special materials · optional with coating
- Up to 40.000.000 mPas
- 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
- 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.
Meltpump on moveable cart
Melt pump on mobile cart with angular gear and 90 ° angled motor.
A variety of variants are possible, for example:
- Melt pump on mobile cart with angular gear and 90 ° angled motor (vertically upwards)
- Melt pump on a mobile cart with angle gear and 90 ° angled motor (horizontal to the side)
- 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