Ring Shear Tester by Dr Dietmar Schulze
There have been many methods developed over the years to
characterise the flow properties of powders. However, there is only one method
which is universally recognised as having the following attributes:
- Based on solid theoretical science
- Robust and Accurate
- Producing data that relates to real physical
properties
- Simple to use
This method is called:
Shear Testing. This
method was developed by Jenike in 1965 and followed up by Carr and Walker.
However, the first generation of testers using this method were awkward to use
and labour intensive.
Schulze started to develop a tester for his own work.
His tester was based on the Jenike principle, since this was the only true way
of measuring powder flow, but, more importantly, he wanted a tester that was
simple, practical and accurate to use.
As a result the first Ring Shear Tester was developed.
This led to much outside interest and encouraged Dr. Dietmar Schulze to develop
the method further which has given rise to the current range of products
described below.
Two Instruments for all powder flow needs
Both testers below apply the Shear Testing Method and
are designed for different particle size grades.
The
RST-XS
This tester is compact and bench mounted. Designed for
applications with powders of up to 1.5 mm in particle size.
This tester is
particularly well suited for small sample volumes |
 |
|
The RST
01.PC
This tester is floor mounted and designed for handling
powders wtih large sample sizes. This also includes coal, cereals, soil and
other coarse materials. |
 |
|
|
|
|
|
|
Applications
The Ring Shear Testers can be used for simple
determination of batch to batch variations and quality control. The RST-XS is
particularly popular in the pharmaceutical industry for the detailed
characterisation of drugs, excipients and formulations.
Beyond the fact that the Shear Test is the only method
where the values have any understandable meaning, the key features of the
tester are:
- simple to use
- very reproducible
- able to charactersise small changes in flow
behaviour
- measurement of caking or time consolidation
A FURTHER
unique aspect of the Jenike method
is that the parameters measured by the shear method allow the user to either:
- Design hoppers, silos and feeders to suit a
particular powder's properties (hopper angle, opening size and wall material).
This will ensure mass flow and prevent effects such as: arching, funnel flow,
flooding etc.
- Check that a powder will flow through an existing
processing line, by checking whether the powder flow properties are compatible
against the exising plant set-up.
For further information
and prices, please click here.
Further details on Dr Dietmar Schulze's expertise and
company can be found
here.
