Capillary Rheometry Units RH7 and RH10

Advanced, powerful floor standing capillary rheometry units suitable for research and product development.

Since its launch, the Rosand RH7 has set new standards in research level capillary rheometry. Today, the Rosand RH7 is used in several hundred research laboratories around the world for a range of rheometry applications including polymers, foods, coatings and ceramics.

Malvern has continuously developed the original RH7 design and its operating software to produce a new generation of floor standing capillary rheometry units with market leading performance characteristics and capabilities. The RH7 and RH10 rheometry units retain much of the robust 'H' frame design principle, which lies at the heart of the instruments' ability to operate under high loading conditions. A new digital drive system, gives the RH7 and the RH10 unsurpassed rheometry performance in terms of speed control, accuracy, and dynamic operating range. This new rheometry hardware is supported by the latest generation of 32 bit Windows™ based software, Flowmaster™, with many new experimental possibilities.

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Specification
Features
Accessories

Specification

Drive Force:: 50kN (RH7)

100kN (RH10)
Frame Stiffness:: 250kN
Drive Speed Maximum:: 600mm/min (RH7)

1,200mm/min (RH10)
Dynamic Speed Range:: 240,000:1
Temperature Range:: Ambient to 400ºC, 500ºC Option,
twin bore barrel

Low temperature cooling coil Option.
Min temperature 5ºC, twin bore
Bore Diameter:: 15 mm Standard, 9.5, 2, 19 & 24 mm bore options
Barrel Bore Length:: 280mm
Barrel Material:: Standard Nitrided Steel, Hastelloy or
Stainless Steel options.
Pressure Transducer Ranges (PSI):: 30,000, 20,000, 10,000, 5,000, 1,500,
500
Pressure Transducer Accuracy:: Better than 0.5%
Dies:: Tungsten Carbide, precision +/- 5
micron
Die Diameter:: 0.5 to 3mm Standard, other diameters
available to special order
Software analysis functions:: Calculation of non-Newtonian Index

Calculation of Bagley Correction by
Orifice Die and Extrapolation Methods

Calculation of Rabinowitsch
Corrections

Hagenbach Correction for fluid inertia

Cogswell Convergent Flow
Model/Extensional Flow Assessment

Extensive Plot and Print Options

Data Export
Optional Software Module:: Melt Fracture/Flow Instability Test
Software

Wall Slip Analysis Software

Material Degradation/Thermal Stability
Test Software

Low Speed Degradation Test Software

ETA-0 Analysis Software

Stress Relaxation Test and Analysis
Software

Laser Die Swell Options

Single Axis Laser Die Swell:: Resolution 10 microns
Single Axis Twin Extrudate Laser Die Swell:: Resolution 10 microns
Dual Axis Laser Die Swell:: Resolution 10 microns
Single Axis High Resolution Laser Die Swell:: Resolution 1 micron
Dual Axis High Resolution Laser Die Swell:: Resolution 1 micron

Die & Melt Cutters

Melt Cutter Single Strand:: Die to cut distance : 100 to 160 mm

Die to Sensor distance (strand length):
150 to 210 mm (50 mm below cut)

Recommended maximum shear rate:
1000 s^-1
Melt Cutter Twin Strand:: Die to cut distance: 100 to 160 mm

Die to Sensor distance (strand length):
150 to 210 mm (50 mm below cut)

Recommended maximum shear rate:
1000 s^-1

Hardware Accessories

Slot Die assembly:: Slot Height 0.5 to 2.5 mm
PVT (Pressure, Volume Temperature) System
Haul Off/Melt Strength System:: Haul off motor/nip roller speed range:
2000 m/min max

Dynamic speed range > 100,000:1

Precision balance 2N capacity,
0.0001N resolution

Haul off die dimensions - 2.0mm (D) x
20mm (L) x 180° (Entrance angle)
Nitrogen purge

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Key Features and Benefits

Rosand Twin Bore Principle
Malvern was the first manufacturer to introduce the twin bore measurement principle in a commercially available rheometer unit. Simultaneous measurements can therefore be made on both long and short dies to determine the inlet pressure drop at the die, and therefore absolute viscosity, using the Bagley method. More commonly, Rosand 'zero length' dies are used to directly measure the inlet pressure drop and measure the extensional viscosity using the Cogswell method. The twin bore rheometer technique gives obvious experimental advantages including improved throughput since both experiments are preheated simultaneously. Alternatively, the software can be configured to run a two material test, thus measuring the apparent viscosity of two different materials simultaneously.

Rigid 'H' frame design
The 'H' frame design principle gives a vertical frame stiffness well in excess of that achievable with cantilever or 'C' frame designs. The frame design is effectively rigid at loads many times in excess of the 100kN measurement limit. This is an important consideration in transient tests such as PVT, which rely upon compliance free measurement for accurate volume determination.
Bi-Modal speed control.

Malvern has developed a bespoke Bi-Modal digital speed control technology to control the latest generation of capillary rheometers. The technology uses different speed control algorithms suited to high and low speed rheometer operation in order to optimize performance. This gives the rheometer units an impressive dynamic range in speed control. In practice, the lower limit is determined only by long experimental times at low shear rates but a dynamic range in speed of in excess of 200:000:1 is available if required. This greatly enhances the rheometer's flexibility and means that a greater range of shear rates can be covered using a particular die.

Integral fume chamber with extraction
For operator safety, the RH7 and RH10 capillary rheometers are equipped with a safety interlocked fume chamber with fan extraction of the gases to a vent at the back of the rheometer unit. An extractor fan is also situated below the rheometer barrel.

Floor standing design
The floor standing design affords the rheometers with an open architecture below the barrel and heater assembly. This space can be used to accommodate other experimental options such as die swell measurement, a slot die, haul-off (melt strength) and a haul-off (post-extrusion) oven.

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