03.04.2009 SYN-setral-HSP/N The family of greases for high-speed applications
from the company Setral was extended by a new
product. The new grease for high-speed
applications SYN-setral- HSP/N (n*dm factor
approx. 1.7 millions) was introduced after
intensive laboratory- and field tests.
Apart from savings due to longer service life at
maximum bearing speed, high temperatures, low
evaporation, long relubrication intervals,
SYN-setral-HSP/N convinces by smooth operation
with very low rolling resistance. Reduced
temperatures in critical applications and
extended service life of bearings are benefits
that are welcome when it comes to reduction of
maintenance costs and avoiding downtimes.
SYN-setral-HSP/N is very well suitable in a far
range of temperatures and thus for low temperature
applications. |  |
16.11.2007 PRO-setral-PL 941 Dans la pratique, la protection de surfaces
métalliques polies et hautement polies, de moules,
outils et mécanismes, reste difficile. Que le
produit soit à base d'huile ou de cire, les taux
de rebus, tous comme les temps de nettoyage, sont
non négligeables, malgré tout, la protection
anti-corrosion reste insuffisante.
PRO-setral-PL 941 est un produit anti-corrosion,
neuf et innovant, à base de graisse, développé par
Setral. Celui-ci allie tous les avantages des
protections traditionnelles à base d'huile et de
cire. Il s'évapore à +70°C sans laisser de
résidus, est hydrophobe et ne se répand pas à
l'intérieur de l'outil.
N'hésitez pas à nous demander un échantillon
gratuit. |  |
16.11.2007 No degreasing prior to painting Setral develops metal working fluids for stamping
and forming operations.
CUT-setral-CST-range simplifies stamping and
forming operations of metal parts. Because of
extremely low residues no cleaning is needed.
CUT-setral-CST-range was especially designed for
stamping and forming operationsSetral simplified
the production process as an expensive cleaning
after forming operations is not necessary and no
compromise in efficiency has to be made.
Metal working fluids – no matter if for cutting or
non-cutting operations – have to handle a wide
range of functions: They have to cool, to extend
tool life and to provide exactly processing.
Metal cutting processes like grinding, milling and
drilling release extreme high energy, which needs
intensive cooling. Therefore, water miscible metal
working fluids (cooling lubricants) are mainly
used. For non-cutting processes non water miscible
metal working fluids are used which are mainly
based on mineral oils or bio-degradable rape oil
or rape oil derivates.
If non water miscible metal working fluids are
used, work parts mostly have to be cleaned after
forming. This is particularly important if work
parts are produced for food- or pharmacy industry
– for example tubes, screw caps, bottle caps and
cans.
Residues are also critically if work parts have to
be over-painted. During production of small parts
adhesive force is formed and further processing is
difficult.
If parts contaminated with metal working fluids
get in contact with plastics or elastomeres
incompatibilities could appear which result in
colour changes, swellings and hardness changes.
Cleaning of work parts is always one step more
which takes up time and causes waste, which has to
be disposed expensively. Disposal cost will
increase continuously in the next years.
Dilutions only reduce after-effects
Some companies offer metal working fluids based on
solvents which are usually simple dilutions from
common products. The problem of residues with the
mentioned after-effects are only reduced but not
eliminated by them. Setral developed with
CUT-setral-CST range a technology which is nearly
residue-free without reducing efficiency of
products.
This was made possible by tailor-made additive
selection by means of the RVT testing machine
which was developed and constructed together with
the Technical University in Darmstadt.
Measuring principle:
A fixed test ring is pressed for one minute to a
rotating test ring. Temperature and load can be
adjusted. The test ring axles stand right-angled
to each other. The contact area is wetted with the
metal-working fluid. The load is increased in
stages and then the surface of the wear calotte is
judged. The smaller the surface of the wear
calotte, the better the load carrying of the
tested oil.
The correlation between the measuring principle
and practical application is markedly good.
Laboratory and practical tests designed a product
range which satisfies demands from various
appliers. This product range contains standard
products with a wide operation field for different
kinds of metal, material thickness and sequences
as well as individual adjusted products for only
one single applier.
There were solutions developed for simple
applications like deep-drawing from screw caps or
tubes. These products evaporate nearly
residue-free.
Besides the selection from additives it was
esteemed on physiologically toleration. Therefore
these products are suitable for food- and
pharmaceutical industry.
But also products for heavy applications leave
only little residues, so over-painting is possible
without problems.
Evaporating rate from the products could be
adjusted on request. But there has always a
compromise to be made regarding the flash point.
The high-speed evaporating A II-products should be
applied where it is acceptable to safety
technologies.
|  |
16.05.2007 The Influence of Additives in Lubricants
Introduction
In the early times of lubricants, there was no
demand for high performance in terms of life time
lubrication, thermal stability or anti wear and
anti friction control. By the time, machin-ery
development evolved and the requirements for the
lubricants grew continuously. At the beginning
simple additives, derived from natural fatty oils,
e.g. lard oil, fish oil etc. were used to improve
the load carrying capacity. Nowadays this is no
longer sufficient in terms of performance but also
because of environmental concerns. Either because
of the animal sources for the fats, use of heavy
metals, toxicity or simply new regulations such as
GHS (Global Harmonised System) or REACh
(Registration, Evaluation and Administration of
Chemicals).
The range of additives is very complex and to find
the right combinations is not always an easy task
to fulfil. This article should show examples what
can properties be achieved by adding the right
additives to the lubricant. An ideal method to do
so is to use tribometers. These are machines,
simulating the situations as one can find them in
the contact area of moving parts being in relative
motion to each other.
Tribometers - Dynamic Four Ball Tester (DFBT) &
Friction and Wear Tester (RVT)
The DFBT and RVT are newly developed tribometers
which are very valuable for develop-ing and
investigating lubricants.
Both test machines are easy to handle but at the
same time very versatile in terms of test
parameters.
The DFBT is an innovative tribometer to
investigate the tribilogical properties of
lubricating greases and pastes. The most
significant difference of the DFBT compared to the
Shell four ball tester standardized according to
DIN 51350 are the base balls which are not fixed
and can freely move within the testing pot. By
means of setting the load and speed the ratio
between sliding and rolling friction can be
influenced. This enables to simu-late the dynamic
conditions as they can be found in a rolling
element bearing. By choosing the right parameters
it is possible to determine the friction and wear
in a broad range.
The RVT was developed to test friction and wear
of oils and semi fluid greases as an alternative
to the Timken and Reichert tester and as a
consequence its measuring principle is based on a
similar geometry.
The testing machine basically consists of a
rigidly mounted test roll, which is pressed
against a revolving friction wheel by means of
leverage. The friction wheel is immersed with its
lower third in the sample (~15ml) under test, and
its rotating speed is of such a rate, that a
sufficient quantity of lubricant will always get
to the contact surface of the test roll and the
friction wheel.
As with the DFBT it is possible to determine
friction and wear properties under various
conditions. In difference to Timken and Reichert
tester the much wider range of tempera-ture, speed
and load settings offer a broader testing variety.
DFBT – Test-Examples
A high-performance additive-system is especially
efficient in the mixed-lubrication regime. When
used under hydrodynamic conditions (no contact
between the metal surfaces), there is hardly any
advantage in using high-performance additives
compared to conventional products.
Especially in applications with changing loads
(vibration, oscillating movement etc.) or
run-ning-in phases mixed-lubrication is
predominant.
In the mixed-lubrication area however the
additive-system deploys its full action and with
controlled abrasion it produces smooth surfaces
with considerably increased load carrying
properties.
As a result the internal friction is reduced
resulting in
- lower temperature
- higher efficiency
- longer life-time of the lubricant and
tribo-element
- longer re-lubrication intervals
- attenuation of the noise level
As an example diagram 1 shows how a
high-performance additive-system works. By
in-creasing the load, at constant speed, the
friction torque increases accordingly. When
reaching the mixed lubrication regime a sudden
increase of the torque can bee seen and soon
following recovering to lower torque. Reduction of
the load shows that the torque in general is lower
than before. This is clearly the influence of the
additives.
Diagram 1: DFBT – additive testing
RVT – Test-Examples
Influence of solid lubricants
As shown before in the DFBT-test, similar to the
situation in a rolling bearing, the perform-ance
of additives can also be demonstrated in the
RVT-test. This represents pure sliding friction as
present in sliding bearings, drive ways or chains.
Diagram 2 shows one example where the same base
oil composition is treated with differ-ent
additive packages. Again it is demonstrated, that
at low loads the influence of the addi-tive is
minor. The moment the load increases the wear gets
higher, depending on the type of additive. Varying
not only the load but also the temperature , Chain
oil is often used in a wide temperature range and
therefore it is important to know how the load
carrying capac-ity varies over the temperature.
The test parameters were 50°C and 1500 rpm
(~3,5m/s). According to these results oil b,c and
oil e seemed to be the best candidates. Repeating
the tests at 100°C, 150 and 200°C showed that the
additive combination in oil e have per-formed
satisfactory whereas oil b and c failed already at
150°C.
Diagram 2: RVT – additive testing – different
additive packages
Diagram 3 shows a similar testing as in diagram 2
but in contrary the same additive pack-age is used
in different base oils. This is to demonstrate,
that the performance of an addi-tive package is
also very much depending on the type of oil it is
used in.
There is no multi-functional additive-package for
any kind of application.
Diagram 3: RVT – additive testing – different
base oils
Conclusion
The examples shown are just a little extract from
a lot of tests, being performed on the two
described tribometers to develop high-performance
additive-systems. This helps to under-stand the
the triboligical system in the application, which
is essential to offer the best pos-sible
additive-system for the lubricant to be used., to
offer tailor-made solutions.
Josef Barreto-Pohlen
Dipl.-Ing. (FH)
Technical Director
Setral Chemie GmbH |  |
