Polyester (UPE)
Unsaturated polyester resins are the most commonly used for the
composites industry. Polyester resins have a good balance of
mechanical, electrical and chemical properties. The polyester
resins are mainly used in glass fibre profiles. Typical mechanical
properties of the polyester/glassfibre profiles are described in
the following table.
|
|
Unit |
Structure = UCU |
Structure = U |
|
Typical glass content |
[%-vol]
|
55-58 %
|
58-65 % |
|
Tensile strength
|
[Mpa] |
600-900
|
1000-1200 |
|
Tensile modulus
|
[Mpa] |
38-42 |
42-45 |
|
Flexural strength
|
[Mpa] |
700-1000 |
1000-1300
|
|
Flexural modulus
|
[Mpa] |
35-40
|
40-43 |
|
Coefficient of thermal expansion
|
[10-6/K]
|
9-11
|
6-8
|
|
Density
|
[kg/dm3]
|
1.9-2.0
|
1.9-2.0
|
Structure: U = unidirectional, C = Cross-wound
Polyester resins can be modified so that they are
flame-retardant of self-extinguishing.
The polyester resins have good chemical resistance
properties. The chemical environment have to be known before a
polyester or vinylester resin can be chosen. Polyester resins are
good in weak alkalis and excellent in weak acid conditions.
The maximum recommended operation temperature is 80°C for
the basic grade polyesters. Modified versions are also available
Vinyl esters (VE)
Vinyl ester resins combine the best features of polyester- and
epoxy resins. The strength is good and the resin has a very good
chemical resistance in acids and alkalis environments, especially
at high temperatures. The glass fibre vinyl ester profile has good
electrical and thermal insulation properties.
Epoxy based vinyl ester resins have good chemical resistance
at elevated temperatures.
The maximum recommended operating temperature is 90-150°C.
Modified versions are also available.
Epoxies (EP)
Epoxy resins have very good properties and are commonly used
with high performance reinforcements, e.g. carbon of with glass
fibres when the reinforcement content is very high.
Different specific properties can be created by changin
hardener systems.
Other resins
Exel can offer a wide range of other resin system for your
applications. For example resin systems for very high temperatures,
fire retardent systems or systems for very aggressive environments
Resin comparison table
|
|
Polyester |
Vinylester |
Epoxy |
Other |
|
Cost |
1 |
2 |
3 |
4 |
|
Strength |
2
|
2 |
1 |
2 |
|
Chemicals
|
2 |
1 |
1 |
2 |
|
Electrical
|
2 |
2 |
1 |
1-3 |
(Legend: 1= superior | 2= exellent | 3 = good)