COMPOSITE MATERIALS
( winding and pultrusion)
|
Winding
Wound composites are manufactured by Filament Winding process. FW is a wet technology for setting fibre rein- forcements with the help of numericalcontrol (CNC) machines which at the same time enable designing (the calculations of optimalforms) and extreme precision of composite structure and thus guarantee high
quality. With optimal roving position, proportion, fibre selection and suitable resin we obtain:
|
- high mechanical properties
- pressure resistance (inner and outer)
- big torsion stability
- temperature stability
- high electric and thermal resistance |
- small thermal expansion coefficient
- corrosion resistance
- low specific density
- electric conductivity
- good sound isolation |
| |
  |
The table of tube profile properties made of epoxy resin reinforced by EC glass fibres; thickness 3 mm
(measurements done at 200 C and relative moisture 65 %).
PROPERTIES |
UNIT |
VALUE |
Volume density |
kg/m3 |
< 2000 |
Water absorbtion (thickness 10mm: 24h in water) |
% |
0.025 |
Elasticity module |
Gpa |
35 |
Axial tension strength |
Gpa |
0.35 |
Radial tension strength |
Gpa |
0.75 |
Compressive strength parallel with layers |
Gpa |
0.23 |
Compressive strength rectangular on layers |
Gpa |
0.81 |
Bending strength (flat test specimen) |
Gpa |
0.26 |
Electric strength (rectangular on layers; thickness 3mm, 20 oC in oil) |
kV/5 min |
40 |
Electric strength (parallel with layers 20 oC in oil) |
kV/5 min |
40 |
Dielectric constant at 50 Hz - 2kV mm |
|
5.35 |
Dielectric constant at 1 MHz |
|
4.35 |
Power loss factor (tg delta) at 50 Hz |
|
<0.01 |
Power loss factor (tg delta) at 1 MHz |
|
<0.01 |
Pipe surface resistance |
M ohm |
1.00E+08 |
Specific resistance |
M ohm |
1.00E+08 |
Surface leakage resistance (IEC 122) |
V |
600 |
Temperature class |
o C |
F(155 oC) |
|
|
Pultrusion
The technology of pultrusion enables the production of profiles different in forms and dimensions, from simple round and rectangular to hollow, bent or any other special cross-sections, and it guarantees constant high quality and dimensional stability within close tolerances. Different resins, different fibre reinforcement types and their arrangements can be adapted to suit specific requirements in individual application. With extra pull winding section it is possible to manufacture tubes and hollow profiles which have a part of fibres in tangential direction. With incorporation of reinforcements which have fibres oriented also in transversal direction the mechanical properties in this direction are significantly better.
Composite materials are anisotropic. Properties differ in different directions. General characteristics of Trivapul profiles depend on the structure and construction of the composite and also on the direction. That is why for instance mechanical properties in direction parallel to fibres are much better than in direction rectangular to fibres. In the table below the approximate values of uni directional Trivapul profile properties are listed. Mechanical properties in direction parallel to fibres are of higher values and mechanical properties in transversal direction are of lower values.
|
|
 |
|
PHYSICAL PROPERTIES
|
UNIT |
VALUE |
STANDARD |
|
Density |
kg/m3 |
1.6 - 2.2 |
DIN53479 |
ISO 1183 |
Glassfiber content |
vol% |
40 - 70 |
|
|
Thermal coeff. of expansion |
1/K |
..10E5 |
|
|
Thermal conductivity |
W/mK |
..0.3 |
DIN52612 |
|
Water absorbtion |
% |
<2 |
DIN53472 |
ISO 62 |
HDT |
o C |
150 - 220 |
DIN53461 |
|
|
MECHANICAL PROPERTIES
|
UNIT |
VALUE |
STANDARD |
Tensile strength |
Gpa |
0.02 - 1.0 |
DIN53455 |
Jungs modulus |
GPa |
4 - 50 |
DIN53457 |
Elongation at rupture |
% |
..2 |
DIN53455 |
Compression strength |
Gpa |
0,05 - 0.5 |
DIN53454 |
Flexural strength |
Gpa |
0.02 - 0.9 |
DIN53452 |
Impact strength |
kJ/m2 |
50 - 150 |
DIN53453 |
|
ELECTRICAL PROPERTIES
|
UNIT |
VALUE |
STANDARD |
|
Specific resistance |
ohm cm |
10E10 - 10E15 |
DIN53482 |
|
High voltage break down |
kV/mm |
5 - 30 |
DIN53481 |
|
Dielectric constant |
|
4 - 6 |
DIN53483 |
|
Loss factor (tg delta) |
|
0.01 - 0.05 |
DIN53483 |
|
Temperature class |
o C |
130(B)-155(F)-180(H) |
VDE 0304 |
IEC 85 |
|
antennas
