Filament Winding, Carbon Fibre Types in Composite Tubes
A tube is comprised of several layers, the fibre type and angle
for each layer is arranged to give the overall mechanical properties
required by the application.
(Properties listed below are for composites made from UD fibres
@ 60% Vf)
A low cost fibre with good strength, but relatively low stiffness
and high density.
Typically UTS 1.0 Gpa Modulus (Ex) 40 Gpa Density 1.9 g/cc
Tradenamed 'Kevlar' or 'Twaron', aramid fibres have excellent
tensile strengths, nearly twice as stiff as glass fibre, also
lighter, but often needs to be combined with other fibres to
achieve acceptable compressive strengths.
Machining can be a problem.
Typically UTS 1.3 Gpa Modulus (Ex) 75 Gpa Density 1.4 g/cc
Carbon Fibre (Standard Grade)
Standard grade carbon fibres have a good combination of strength
with stiffness. With a specific modulus of 92, over 3 times
that of metal (Steel and aluminum are both the same) carbon
fibre / epoxy laminates are finding increasing application.
Typically UTS 1.5 Gpa Modulus (Ex) 130 GPa Density 1.6 g/cc
Carbon Fibre (Special Grades
Standard grade carbon fibre (T300, HTA, etc) have mechanical
properties with out resin of approx. 3 - 3.5 GPa tensile strength
and 230 - 240 GPa Tensile modulus.
Carbon fibre manufacturers are constantly trying to
improve the modulus and strength of their fibres, tensile strengths
go up to 7 GPa and Tensile modulus up to 700 GPa, however it
is not possible to get a fibre with both the above properties,
'strong' fibres are not as 'stiff' and visa-versa.
There are many grades now available, however increased properties
means higher prices, up to £600.00 per Kg (not for the faint