Vulkollan
is a material with an elasticity similar to rubber.
In its traditional form it is a polyurethane elastomer
with a base of
1.5-naphthalen-diisocyanate (Desmodur 15), polyester
polyhydric
alcohol and special chain extenders. The material
is produced by
means of a hot-cast moulding process.
PERFORMANCE:
Vulkollan based elastomers are characterised by
a
number of exceptional features, the combination
of
which makes them ideal for a wide range of special
and
demanding applications. They have a high resistance
to dynamic stresses, good resistance to UV rays,
ozone, grease and oils, and are not easily affected
by
temperature. They feature a high wear resistance,
low
permanent deformation, resilience upon impact,
as
well as a high tear resistance.
Some examples:
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Wheel mouldings
Maximum load capacity, low heat accumulation and minimum permanent deformation
due to compression, virtually no flattening.
Many manufacturers of electric lifting machinery exclusively use Vulkollan wheels. |
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- Coupling elements
High elasticity factor enables a greater power transmission capacity thanks to
the low dampening, material heating is kept to a minimum.
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- Centrifugal cleaners
High elasticity factor enables creation of self-supporting structures. High wear
resistance guarantees product a long life.
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- Vulkollan ® decouplers
Low permanent deformation and low dynamic rigidity enable sound proofing and
ensure longer product life.
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- Vulkollan ® O-rings and scaper rings
Low permanent deformation due to compression, high compactability and oil and
fat absorbency are indispensable characteristics for long-lasting, self lubricating
O-rings.
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We produce Vulkollan in a range of hardness
degrees between 65 Sh°A and 95 Sh°A.
Vulkollan's mechanical properties are especially noteworthy
between 80 Sh°A and 95 Sh°A, and these are
the types that claim a larger share of the market.
TYPICAL PROPERTIES
| |
Test st. |
Units |
Vulkollan® grade |
| Mechanical
properties |
ISO |
|
18 |
21 |
25 |
30 |
| Shore A/D hardness |
868 |
|
83/29 |
89/35 |
92/36 |
95/40 |
| Density |
1183 |
Mg/m3 |
1,26 |
1,26 |
1,26 |
1,26 |
| Stress at 100% strain |
37 |
Mpa |
4,3 |
5,9 |
8,0 |
10,6 |
| Stress at 300% strain |
37 |
Mpa |
7,8 |
10,4 |
12,8 |
15,8 |
| Ultimate tensile
strength |
37 |
Mpa |
50 |
54 |
53 |
42 |
| Elongation at break |
37 |
% |
660 |
700 |
740 |
692 |
| Tear propagation
resistance |
34 |
kN/m |
31 |
38 |
54 |
67 |
| Rebound resilience |
4662 |
% |
65 |
64 |
62 |
61 |
| Abrasion |
4649 |
mm3 |
37 |
32 |
28 |
26 |
| Taber abrasion
(S42/4,9N) |
9352 |
mg |
3,5 |
4,0 |
6,1 |
7,5 |
| Compression set |
815 |
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| 70h/23°C |
|
% |
8 |
9 |
10 |
14 |
| 24h/70°C |
|
% |
18 |
19 |
19 |
20 |
| Linear coefficient
of thermal expansion |
VDE 0304 |
10-6.K-1 |
da 160
a 200 |
da 160
a 200 |
da 160
a 200 |
da 160
a 200 |
| The figures are intended
as guide values for a standard Vulkollan® formulation |
Compact Vulkollan, chemical and electrical
characteristics
Polyester-based Vulkollan is subject to the impact of
hot water, bases
and acids, in a process known as hydrolysis. In organic
solvents, there
is a significant degree of swelling, and as swelling
increases, the
mechanical properties are compromised. The solvents responsible
for swelling the material physically can be removed later
from the
elastomer through a drying process. Many plastics contain
non-fixed
additives, such as plasticizers, which can be extracted
by washing,
through the contact with solvents, with consequent alteration
of the
material. Vulkollan contains no plasticizers, and modifications
of its
characteristics following the extraction of the non-fixed
additives have
not been noted.
The material's features, as a result, are completely
predictable.
CHEMICAL PROPERTIES
| |
Swelling
in % by weight |
Evaluation
of
stability |
| Water |
< 2 |
+ |
| ASTM oil I |
< 2 |
++ |
| ASTM oil II |
< 2 |
++ |
| ASTM oil III |
< 10 |
0 |
| Light fuel oil |
< 5 |
+ |
| Transformer oil |
< 2 |
++ |
| Dry cleaning fluid |
< 10 |
0 |
| Benzene |
< 100 |
-- |
| Toluene |
< 100 |
-- |
| Methylene chlorinde |
< 300 |
-- |
| Carbon tetrachloride |
< 100 |
-- |
| Trichloroethane |
< 200 |
-- |
| Methanol |
< 10 |
0 |
| Ethanol |
< 10 |
0 |
| Ethyl acetate |
< 50 |
- |
| Acetone |
< 50 |
- |
| ++
very good, + good, 0 satisfactory, - moderate,
-- not suitable |
The
effect of compression
The loading and release curves resulting by tracing the lines characteristic
of elasticity define a zone
noted as loss due to hysteresis. The loading and release curves in Vulkollan
are closely aligned, denoting
a very low loss of energy. This characteristic is highly advantageous in the
event the material is
subject to repeated dynamic stresses for a long period of time.
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Characteristics
of elasticity at different temperatures
Compressive deformation curves exhibit Vulkollan's exceptional thermal
stability, with characteristics
of elasticity differing only minimally between 0°C and 80°C.
For project designers, this offers the possibility
of predicting deformation, it being virtually constant, on a wide range
of temperatures. This is
an important requirement for the safe and reliable performance of the
material.
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