Gear Pump: Continuous Rubber Preformers

Image 1 Image 2 Image 3 Image 4 Image 5 Image 6 Image 7 Image 8 Image 9 Image 10

You can see even more videos of our range at our YouTube channel here

We currently have the following Gear Pump available for sale at a special price.

Barwell Gear Pump
Barwell BPP70 Gear Pump Preformer (ex-demo)

If you are interested in this machine, contact us by phone on +44 (0) 1480 832850or by email

Technical Data

Technical Data






Maximum Output

70 kg/h 180 kg/h 320 kg/h 550 kg/h 1200 kg/h

Maximum Pump RPM

55 50 40 36 30

Maximum Die Size

64mm 64mm 140mm 190mm 190mm

Maximum Pressure (bar)

350 350 350 350 350

Accuracy (volume) UP TO

 +/- 1%  +/- 1%    +/- 1%   +/- 1%   +/- 1%

Cutter Speeds (Variable)

50-500   50-500 50-500   50-500 50-500 

Screw Size

50mm 75mm 90mm 120mm 150mm

Screw L/D Ratio

10:1 10:1 11:1 11:1 11:1

Heating/cooling Zones

3 5 5 5

Product Banner

If you’re gearing up for increased business or have long production runs, a Gear Pump Preformer will provide you with continuous production capability for your preforming. It will also reduce your machine set-up time and negate the need to pre-heat rubber on a two-roll mill, when compared to using ram preformer which is the preferred solution for batch production preforming.

The Barwell Gear Pump Preformer is a fully automated and highly advanced screw extruder with integral gear pump specifically designed to provide high levels of control and processing flexibility for the continuous preforming or extrusion of almost any form of rubber compound. It combines three key elements, the plasticising properties of a cold feed screw extruder, the volumetric flow control properties of a gear pump and the proven Barwell cutter system. 

  • Excellent for long production runs
  • Fully automated which reduces user dependence and increases productivity
  • Technologically advanced processing providing optimum levels of dimensional stability, product consistency, accuracy and superior quality
  • An intelligent process that ensures very high temperature control providing versatility at low temperatures
  • Complete processing flexibility combing extrusion, cutting and check-weighing 
  • A cost-cutting solution reducing material wastage and labour costs as well as the need to pre-heat your rubber on a two-roll mill
  • A safe, reliable and user-friendly system 

How does the Barwell Gear Pump work?
Material is delivered to the gear pump by a screw extruder which masticates the material prior to entry. The masticated material is pulled into the pump by intermeshing herrigibone gear teeth at a constant rate, irrespective of screw rotation speed, ensuring the gear pump cavity remains full. Minimal shear is generated in the gear pump so increases in material temperature are minimal - important when processing temperature sensitive materials.

The material is then compressed at the outlet point at a constant rate enabling precise control over dimensional stability. The constant rpm of the gear pump and monitoring and regulation of inlet pressure help overcome extruder pulsing. This assists during strip feed change-over. The gear pump is independently driven but controls the screw rpm by means of inlet pressure monitoring.

Without a gear pump the pressure build up and extrusion uniformity is directly influenced by the screw rotation and compound variations. With a gear pump these variations are monitored at the pump inlet and adjustments made automatically to maintain constant output flow.

Whilst the pressure at the inlet varies (due to material changes, feed variation etc.), the pressure at the outlet of the gear pump remains constant ensuring improved extrusion quality and control of extrudate dimensions.

By keeping the gear pump rpm constant, it is possible to influence the plasticising effect on materials by changing the screw rpm. Increasing the screw rpm increases the inlet pressure and also the compound temperature as greater mastication is achieved during the dwell time in the extruder barrel. This has significant advantages when processing difficult materials that need additional mastication to achieve output requirements.

Material flow through the gear pump is generally linear and dependent on pump rotation speed. Increasing rpm will automatically adjust the screw feed to maintain inlet pressure and cavity fill. This is not influenced by varying material characteristics.

Need further assistance?
Think about tomorrow and grow as a business with a preformer that doesn’t need to stop! 

For full details, download our brochure on our range of Gear Pumps. For further advice on improving your rubber processing requirements contact us on +44 (0) 1480 832850 or email on outlining your needs.