AN-VI by Italeco s.r.l. Moncalieri (TO) - Italy A revolutionary anti-vibration and anti-shock product. Short presentation at http://www.youtube.com/watch?v=y7QNmG3FLBs

1. Via G. Pastore, 8 - 10024 - Moncalieri – (TO) – Italy
Tel +39-011.5690295; Fax + 39-011.5690298
P.I. – VAT IT06539670015 – Cap. Sociale 90.000,00€
www.an-vi-it www.italeco.it
AN-VI: A NEW VIBRATION ABSORBER ELASTOMETER
1 VIBRATION AND THEIR EFFECTS .................................................................................................... 2
2 WHAT IS AN-VI? .................................................................................................................................... 2
3 SHOCKS AND IMPACT VIBRATIONS ............................................................................................... 2
4 SHOCK ABSORPTION.......................................................................................................................... 2
5 CONTINUOUS VIBRATIONS ............................................................................................................... 2
6 AN-VI AND THE ABSORPTION OF SHOCK ENERGY ................................................................... 3
7 REBOUND ELASTICITY OF ELASTOMERS AS A FUNCTION OF TEMPERATURE .............. 4
8 AN-VI DAMPING PROPERTIES .......................................................................................................... 5
9 AN-VI AND TRANSITORY PHENOMENA ......................................................................................... 6
10 MECHANICAL FEATURES OF AN-VI ................................................................................................ 8
11 Examples of AN-VI compounds ............................................................................................................ 9
12 AN-VI AND CHEMICAL AGENTS ...................................................................................................... 11
13 ELECTRICAL FEATURES OF AN-VI ................................................................................................ 12
14 WHERE AN-VI CAN BE USED .......................................................................................................... 12
15 THOSE WHO HAVE TRIED AN-VI SAY…....................................................................................... 13
16 AVAILABLE SHAPES .......................................................................................................................... 13
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2. 2
1 VIBRATION AND THEIR EFFECTS
When machines are functioning , they vibrate, causing wear to their parts and to their supporting structures
reducing the production quality. The vibrations, transferred to structures, are also harmful to people working
nearby.
The vibrating structures create noise which in turn becomes a source of disturbance.
2 WHAT IS AN-VI?
AN-VI is a new member of the rubber family, with substantially different characteristics to those of
traditional elastomers. It has the elasticity of a good rubber but it also has unusual damping capacities: by
deformation it absorbs energy from an elastic material and as a damper it dissipates the energy absorbed.
One part of the energy is converted into heat while the other part is returned so slowly as to have
practically no dynamic effects.
In solid form AN-VI can be used to reduce shock and impact stress effects as a vibration damper.
Foamed it finds use with specific not too heavy loads.
3 SHOCKS AND IMPACT VIBRATIONS
If we compare what happens when a small metal ball is dropped on a slab of AN-VI and on a slab of some
other elastic material, we will see:
The elastic material is compressed and “energized”. This given energy is then returned to the ball which
bounces. Instead AN-VI is slow in neutralizing the impact-inducted deformation and returns to its original
shape with no bounce action, the impact energy is “disapated” inside AN-VI. The absorbed energy is not
given back to the ball and is also filtered out from affecting the underlying surface.
This proves AN-VI’s claims to reduce shock effects and to attenuate impact vibrations generated by
repeated blows of metal on metal.
4 SHOCK ABSORPTION
Another feature of AN-VI is its shock-absorbing capacity.
AN-VI is excellent for use where shock vibration is added to constant vibrations.
5 CONTINUOUS VIBRATIONS
As a rule, machines are insulated from their base plates by vibration-damping supports.
The machine-plus-support system has a natural frequency of oscillation determined by the mass of the
machine and the elasticity of the supports. In operation, the machine vibrates at a frequency depending on
the speed of rotation . If the vibration frequency is higher than the natural frequency, AN-VI absorbs the
energy and decidedly cuts down the transmission of vibration to base-plate.
When the vibration frequency is near the natural frequency, as it is, for example, in the start-up and
stopping stages of the machine, AN-VI acts as a shock absorber, limiting machine oscillation.
Machine-made vibrations are transmitted to the metal covering panels. This then act as a sounding board.
Noise can be reduced by damping the vibrations with suitable material on panels, in such a way that the
mechanical energy associated with the vibrations is then converted into head and dissipated.
A sheet of foamed AN-VI on the metal is the answer.
A metal-panel sandwich with AN-VI filling is an excellent noise-deadening arrangement.
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3. 3
6 AN-VI AND THE ABSORPTION OF SHOCK
ENERGY
Several tests have shown that AN-VI reduces the effects of shock and cuts the vibrations generated by the
impact of repeated blows of metal on metal. The graphs illustrate the force transmitted by a free-falling steel
ball on a load cell Between the ball and the instrument there are 3 test pieces consisting alternatively of
natural rubber, ethyl-vinylacetate (E.V.A.) and AN-VI. The test was performed under equal conditions
(highness of the fall and size of the pieces): AN-VI absorbs the shock energy completely (there is no second
or rebound shock) and this reduces the transmitted force.
FORCE TRANSMITTED BY FREE-FALLING STEEL BALL TO A LOAD CELL WITH
INTERPOSED TEST PIECES OF RUBBER, ETHIL-VINYL-ACETATE AND AN-VI.
(Politecnico di Milano, Servizi di Ricerche Biomeccaniche, 1989)
The value found were:
RUBBER 144
E.V.A. 120
AN-VI 100
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4. 7 REBOUND ELASTICITY OF ELASTOMERS 4
AS A FUNCTION OF TEMPERATURE
One of the major characteristics
which sets AN-VI apart from other
good quality elastomers is its
rebound elasticity. This quantity is
a parameter expressing the
capacity of the material to
dissipate mechanical energy. It is
measured by means of an
instrument called the Rebound
Pendulum
Which measures how much
mechanical energy is put back
into a steel ball falling from a
specific height on to a test piece
of the material under
examination.
With AN-VI, for temperature
between 0° and 30°, less than 5%
of the ball’s prefall potential
energy is put back into the ball.
The remaining 95% is dissipated
by the AN-VI.
On the picture AN-VI’s rebound
elasticity is illustrated in
comparison with that of other
common elastomers, as a
function of temperature. In a
range of temperature from -20° to
+60°C, which includes most
normal applications, the rebound
elasticity of An-VI is decidedly
lower than that of all other
elastomers.
The picture shows the behavior of
AN-VI according to the frequency
of vibration, compared with other
different elastomers.
The chart was defined from the
Politecnico di Torino -
Interdisciplinary Mechatronics
Laboratory during an experiment
carried out using AN-VI to stabilize
electrodynamics rotor-bearings.
The study demonstrated that the
use of AN-VI is the solution also
where other elastomers highlight
various kinds of limits.
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5. 5
8 AN-VI DAMPING PROPERTIES
AN-VI’s capacity in extensively damping both impulse and transitory vibrations as well as stationary and
pseudostationary dynamic actions is apparent in its hysteresis behaviour.
SYMBOL TABLE
time t S
GIVEN AN OSCILLATOR: frequency f Hz
pulsation w = 6,28 f rad/s
displacement s(t) m
speed v(t) = ds(t) / dt m/s
acceleration a(t) = dv (t) / dt (m/s)/s
force F (t) N
mass M Kg
elastic stiffness K N/m
viscous damping B N /(m/s)
hysteresis stiffness C N/m
imaginary unit i
viscous damping factor nv = B / (2 Sqr ad
hysteresis damping factor (K/M)) ad
natural pulsation ni= C/2K rad/s
natural frequency wo= Sqr (K/M) Hz
natural period fo= (1/6,28) Sqr s
natural damping factor (K/M) ad
To= 1/fo
no=nv + ni
F (t) = Ma(t) + Bv(t) + (K + iC) s (t)
Take test pieces of various materials and subject them to a squash s (t) of unit amplitude ( 1 cm ),changing
according to harmonic law ( with pulsation w ). Then:
s(t) = (1 cm) sin (wt)
Graph the relationship between the squash (s) and the force (F) required to produce the desired
displacement
The behaviour shown in the first figure on next page refers to a perfectly elastic material, such as steel.
The relation between ( s ) and ( F ) is a straight line whose slope (K) represents the elastic stiffness of the
sample.
F(t) = K s(t) = K ((1 cm) sin (w t))
The elastic energy ( Ee ) required to cover the load-phase (half circle)
2
Ee = ½ K (2 cm)
Is given back in total in the upload phase.
The behaviour of the elastomers, shown in the other figures on next page, diverges from that of the steel in
that the straight lines of steel becomes an s/F closed curve and represents the hysteresis circle of the
material.
The area enclosed by the curve is a measure of the hysteresis Energy (E) expended in one circle of the
system.
The ratio (Ri) between hysteresis energy (Ei) and the energy associated with the elastic half-cycle (Ee) is an
index of the material’s hysteretic dissipative capacities:
Ri = Ei / Ee
The hysteresis properties of materials are espressed in terms of hysteretic stiffness (C), orhysteretic
damping coefficient, wich has the same dimensions as elastic stiffness (K), and therefore the total force (F)
to be applied to the sample to produce the cycle is given by:
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6. F(t) = (K + iC) x (t) = K (1 cm) sin (wt) + C (1 cm) cos(wt) 6
The ratio ( 2 nl ) between the two stiffnesses represents the loss factor or hysteresis damping factor or
hysteresis damping factor.
The parameter:
nl = C / (2K)
is connected to the Energy ratio ( Rl ) by the formula:
Rl = (3,14) nl
The greater the hysteresis capacity for dissipating mechanical Energy, the fatter is the cycle shape. With the
test, the difference between the behaviours of AN-VI and other elastomers can be quantified.
Given that all good quality rubbers have respectable hysteresis damping factor (ni), AN-VI’s particularly high.
THE HYSTERESIS OF STEEL, RUBBER AND AN-VI
STEEL RUBBER AN-VI
Force (N) Force (N) Force (N)
Displacement (cm) Displacement (cm) Displacement (cm)
PARAMETERS RUBBER AN-VI
Rebound elasticity at 20°C From 20% to 40% From 2% to 5%
Loss factor: 2ni = C / K From 10% to 30% From 120% to’ 80%
Hysteresis factor: ni = C / (2K) From 5% to 15% From 60% to 90%
Energy ratio: Ri = Ei / Ee From 16% to 47% From 188% to 283%
9 AN-VI AND TRANSITORY PHENOMENA
Transitory phenomena have their origin in events which last only for a very short time. A theoretical example,
schematically very simple, is the rectangular impulse illustrated below in the figure, resulting from the
application of a load ( F ), which remains constant for a period of time ( T ). In actual fact the response of the
mechanical system is usually characterized by complex oscillatory phenomena during the loading phase, in
passing from ( 0 ) to ( F ). Higher is the natural damping factor ( no ) of the system quicker is the phenomena
disappearing. The diagrams on pages 10 and 11 give evidence of the differences in behaviour between an
ordinary rubber ( no = 30% ) and AN-VI ( no = 60% ). The extent of displacement depends upon the stiffness
( K ) of the system. Response oscillation amplitude a ( t ) is inversely proportional to the mass ( M ). The
diagrams confirm that significant effects are obtained through the use of AN-VI insofar as the transitory
phenomena caused by the system’s free oscillations are concerned, both in the loading phase and in the
unloading phase. The shorter oscillation damping time also reduces the risk of dangerous synchronizations
due to the superimposing of return waves on the outgoing waves.
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7. The pictures show the transitory for the different materials.
7
Force (N)
Time (s)
RUBBER AN-VI
Displacement (cm) Displacement (cm)
Time (s) Time (s)
2 2
Accelerations (cm/s ) Accelerations (cm/s )
Time (s) Time (s)
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8. 8
10 MECHANICAL FEATURES OF AN-VI
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9. 9
11 Examples of AN-VI compounds
Mixtures with different percentages of AN-VI can be made to obtain different material properties according to
different usages, (e.g.: different specific gravity and hardness or elasticity). You can find below as example
the mechanical properties of 4 different compounds and the frequency response of the M4 at temperatures
of -20 ° C +20 ° C and +80 ° C.
PRODUCT: M1 M2 M3 M4
Density 1,02 1,07 1,14 1,19 kg/dm³
Hardness (DIN 53505) 36 41 51 58 Shore A
100% Young's Modulus (DIN53504) 0,73 1,06 1,85 2,79 MPa
300% Young's Modulus (DIN53504) 1,93 4,5 6,67 10,66 MPa
Tensile Strength (DIN53504) 12,43 13,76 13,79 12,73 MPa
Abrasion Resistance (DIN 53516) - 231 149 84 mm³
Elongation at Break (DIN 53504) 5 0,5 6 1 %
Elongation at Break (DIN 53504) 681 470 444 320 %
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10. 10
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11. 11
12 AN-VI AND CHEMICAL AGENTS
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12. 12
13 ELECTRICAL FEATURES OF AN-VI
AN-VI is classified, from an electrical point of view as an insulating material.
Anyway, even if it cannot be classified as material with ESD protection, the quantity of the charge generated
by triboelectric effect is limited: undergoing to a rubbing process, AN-VI features an accumulation inferior to
500V, while normal insulating plastics gets tens of thousands Volt.
According to the above features, the material results to be particularly suitable to be used in electrical and
electronics field in direct contact with circuitry without any particular risk of conduction or electrostatic
discharges.
14 WHERE AN-VI CAN BE USED
AN-VI is a positive solution in conquering vibration problem in a large number of machines. A major
application sector are those of machines with metal hammering on metal, with reciprocating parts, and
precision machines where protection mast be provided against vibrations coming from neighbouring
mechanism.
APPLICATIONS FOR AN-VI
Industrial sector
Vibration deadening in rotatory and reciprocating machines, linings for hoppers and containers suffering
shock from falling materials, vibratory separators, metal panel deadening, handgrip covers, portable machine
tool uncouplers.
Automotive, Rail , Aereospace, Naval e Yachts
Lining and covers, rebound bumpers, racing car interiors.
Railwais superstructure
Rail chairs, superstructure paltform supports, signlling and shunting box connections.
Building
Slab supports, bearings, joints, floating floors.
Electronics and precision instrumentation
Coverings, equipment supports and fixings.
Hi-Fi
Coverings, supports and fixings for soundboxes and record-players.
Hydraulics
Piping anchorage, pump uncouplers, joint seals.
Office machines
Supports and base plates for printers and computers.
Aeronautics
Helicopter landing platforms.
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13. 13
15 THOSE WHO HAVE TRIED AN-VI SAY…
Research - Politecnico di Torino – Laboratorio di Meccatronica
 "The tests performed with different masses allowed to vary the natural frequency of the
system making it clear that in the frequency range analyzed the behavior of the
material remains unchanged”
 "The tests carried out under different operating conditions show that the behavior of the
material, in terms of loss factor and elastic modulus remains unchanged working with
traction, compression and shear"
 "Working with damping materials, the damping factor may be overly influenced by the
temperature and frequency, the tensile strength may be inadequate, the available
formats can be too thin. Not being afflicted with these problems AN-VI is the solution”
Industry – Azimut Yachts – Avigliana (TO)
 "The reduction of vibratory phenomenon with rubber AN-VI improved by 12.6%
(reduction of 21.9) compared to the value reached by the NBR (9.3%), despite the
thickness of 3 mm for AN-VI and 10mm for the NBR "
 "The vibration values measured show more than one characteristic frequency, but with
extremely low levels. Too low to make any consideration "
 "The rubber AN-VI showed its excellent characteristics, was always superior in
performance"
16 AVAILABLE SHAPES
AN-VI in foamed form (light load) is
distributed in sheets of different
formats and 3 thicknesses (1, 2 and
4 mm). The structure of the material
is magnified in the pictures on the
right.
Cubes with edge 40mm are available in solid form (heavy load), easy
to work with water-jet technology to achieve the desired shape
depending on the specific use
Plates of 40x40mmq size and 2,3,4 and 5 mm thickness are
available in compact form, which can be used as such or die-cut to
get different forms.
In solid form it can also be made basing on special design according to the
customer needs, varying if necessary the compound formula to obtain the
right. elastic properties. appropriate.
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