JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 34

permeability
Focus
Formax, headquartered in Leicester, UK, is
a leader in the development and manufacture of tailored reinforcement material
solutions, offering an unrivalled range of
reinforcements, including carbon and glass
multiaxials, UDs, stitched core and combi
fabrics. The company is supplier to a global
customer base in the target markets of
wind energy, automotive, marine, sports
and industrial, as well as other selected
application areas.

tool vented to atmospheric pressure), the
oil infiltrates the preform stack while the
pressure sensors in the bottom plate detect
the pressure gradient across the stack. Data
acquisition and processing software then
takes these measurements and generates
permeability values and the principal and
secondary flow directions for the fabric
sample.
The results from the fabric permeability
measurement tool have been validated
against the fixture at the University of
Nottingham and it has already been used to
assist customers in the automotive, marine
and tidal energy industries.
To provide more insight into the effect of
fabric architecture on the permeability,
a fabric can be tested at a range of fibre
volume fractions to produce a graph
providing estimates for permeabilities
at a given volume fraction. As Figure 2
shows, permeability drops sharply with an
increase in volume fraction, before levelling out as the volume fraction gets closer
to its theoretical maximum.
These values can be used with analytical
hand-calculation methods and, with the required experience, flow simulation software
packages such as PAM-RTM to provide
data for fill time and locations of dry spots.
A good understanding of the limitations of
such simulation codes is necessary, especially for wind energy customers looking to
analyse their vacuum infusion process. The
modelling of flow through a fixed cavity
volume of an RTM tool is significantly more
straightforward than for the flow under

Fig. 2: The permeability (K) vs. volume fraction (Vf) curve for a carbon fibre biaxial fabric with (red) and without (blue) flow enhancement media. The flow enhancement is a low g/m2 layer of nonwoven thermoplastic
filament which is stitched between the fibre layers to create an inter-ply passage for polymer flow

vacuum bag, due to the variation in cavity
thickness, fabric compression and fabric permeability associated with infusion. In order
to further the advancement of simulation
solutions for vacuum infusion, the company
is funding a four-year engineering doctorate
at the University of Nottingham.
Combined with mechanical testing and process simulation, permeability data enables
the team to engineer fabric architectures
which allow higher and more consistent
infusion rates and result in the optimal laminate quality. A range of different infusion
cores based on polypropylene, polyester,
natural fibre and glass fabric can be included
within the fabric structure to further enhance infusion.

The optimal carbon UD
One focus of Formax's wind energy research
is the development of carbon fibre unidirectional (UD) fabrics designed for use
in the main load-carrying elements of the
blade, which are the spar caps that run from
the root to the tip of the blade. These are
critical structures within the blade, with the
highest mechanical performance (stiffness
and compression strength). This requires
exact fibre alignment and wet-out in order
to produce high-quality laminates with low
void content.
There are a number of options for the
manufacture of spar caps. Glass or carbon
fibre can be used, and the caps can be

34 jec composites magazine / No99 September 2015

manufactured using prepreg or infusion
technology. Typically, blade manufacturers
start to move from glass to more expensive
carbon fibre for blades above 35 m in length
in order to achieve the higher mechanical
properties required. When the business
case prevents the use of high-performance
(but expensive) prepregs, the composite
engineer may look to infusion of dry carbon
UD fabrics for the required performance
at lower cost. With its new permeability
characterization capability, the company
is now developing a range of carbon UDs
with fabric architectures that are bespoke
to spar cap laminates. Permeability can be
optimized in the X, Y and Z directions to
suit the specific spar geometry and infusion
lay-up, whilst maximizing utilization of the
mechanical properties of carbon fibre.
Permeability can be enhanced through
intra-layer or inter-layer fabric architecture
features. Intra-layer features are conventional
elements of a structural fabric (e.g. those created due to a given stitch style) which exist
within each fibre layer, increasing flow rate
during infusion and creating a permanent
feature within the composite. Inter-layer features sit between the fibre layers and act as
polymer flow paths during the infusion process. Formax is developing novel inter-layer
features which are temporary and increase
permeability during the infusion process,
but do not remain in the final composite. n
More information:
www.formax.co.uk


http://www.formax.co.uk

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #99 - September 2015

Cover
Edito
Point of view: The future of mass production
Contents
Companies & Business
In brief
Interview UCI - “Our aim is to ensure bicyclers are safe to race”
Agenda of Events
Applications
Recreational aviation - A recreational airplane as advanced as the latest widebodied aircraft
Sports & leisure - Cork, flax and green epoxy: a perfect balance for a skateboard
Medical - Lightweight emergency medical cot
Market
Natural fibres - Tending towards optimism
SPECIAL JEC FORUMS
Interview - MIT-NECST Lab: a research consortium dedicated to composites in Aeronautics
Conferences - Gain insight into the JEC 2015 Forums conferences programme
FEATURE WIND ENERGY
Wind energy - Double-digit growth continues
Design - A wind turbine without blades
Simulation - Visualizing RTM behaviour using advanced 3D CAE technology
Permeability - Optimizing fabrics for wind blade infusion
Automation - Automation strategies in rotor blade production: preforming vs. direct textile layup
Recycling - Recycling decommissioned composite wind blades
Platform - An internet aid for advances in wind turbine blade design
Research & Development
Graphene - Gambling with graphene, will it pay off ?
Thermal expansion - Boeing simulates thermal expansion in composites with expanded metal foil for lightning protection of aircraft structures
Technology & Innovations
Heating - Power transfer in complex shape heated moulds or functional composites
Manufacturing - Tension control in composites manufacturing
3D printing - A fully biodegradable flax fibre-reinforced thermoplastic filament for 3D printing
RTM/LCM - Fast production epoxies for lightweight automotive composites
Index
In the world
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Cover
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 2
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Edito
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Point of view: The future of mass production
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 5
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Contents
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 7
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - In brief
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 9
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 10
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Agenda of Events
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Interview UCI - “Our aim is to ensure bicyclers are safe to race”
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 13
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Recreational aviation - A recreational airplane as advanced as the latest widebodied aircraft
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 15
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Sports & leisure - Cork, flax and green epoxy: a perfect balance for a skateboard
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Medical - Lightweight emergency medical cot
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 18
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Natural fibres - Tending towards optimism
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 20
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 21
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Interview - MIT-NECST Lab: a research consortium dedicated to composites in Aeronautics
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 23
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Conferences - Gain insight into the JEC 2015 Forums conferences programme
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 25
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Wind energy - Double-digit growth continues
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 27
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Design - A wind turbine without blades
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Simulation - Visualizing RTM behaviour using advanced 3D CAE technology
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 30
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 31
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 32
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Permeability - Optimizing fabrics for wind blade infusion
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 34
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Automation - Automation strategies in rotor blade production: preforming vs. direct textile layup
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 36
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 37
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Recycling - Recycling decommissioned composite wind blades
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Platform - An internet aid for advances in wind turbine blade design
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 40
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Graphene - Gambling with graphene, will it pay off ?
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 42
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 43
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 44
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Thermal expansion - Boeing simulates thermal expansion in composites with expanded metal foil for lightning protection of aircraft structures
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 46
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 47
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Heating - Power transfer in complex shape heated moulds or functional composites
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 49
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 50
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 51
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Manufacturing - Tension control in composites manufacturing
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 53
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 54
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 55
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 56
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 57
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 58
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 3D printing - A fully biodegradable flax fibre-reinforced thermoplastic filament for 3D printing
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 60
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 61
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - RTM/LCM - Fast production epoxies for lightweight automotive composites
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 63
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 64
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - Index
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - In the world
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 67
JEC COMPOSITES MAGAZINE - Issue #99 - September 2015 - 68
https://www.nxtbook.fr/newpress/jeccomposites/jcm2009_136
https://www.nxtbook.fr/newpress/jeccomposites/jcm2007_135
https://www.nxtbook.fr/newpress/jeccomposites/jcm_2020_Q1_Innovation_Report
https://www.nxtbook.fr/newpress/jeccomposites/jcm2005_Special_Issue3
https://www.nxtbook.fr/newpress/jeccomposites/jcm2005_134
https://www.nxtbook.fr/newpress/jeccomposites/jcm2003_133
https://www.nxtbook.fr/newpress/jeccomposites/jcm2001_132
https://www.nxtbook.fr/newpress/jeccomposites/jcm1911_Special_Issue2
https://www.nxtbook.fr/newpress/jeccomposites/jcm1911_131
https://www.nxtbook.fr/newpress/jeccomposites/jcm1909_130
https://www.nxtbook.fr/newpress/jeccomposites/jcm1907_129
https://www.nxtbook.fr/newpress/jeccomposites/jcm1905_128
https://www.nxtbook.fr/newpress/jeccomposites/jcm1903_Special_Issue1
https://www.nxtbook.fr/newpress/jeccomposites/jcm1903_127
https://www.nxtbook.fr/newpress/jeccomposites/jcm1901_126
https://www.nxtbook.fr/newpress/jeccomposites/jcm1811_125
https://www.nxtbook.fr/newpress/jeccomposites/jcm1810_124
https://www.nxtbook.fr/newpress/jeccomposites/jcm1808_123
https://www.nxtbook.fr/newpress/jeccomposites/jcm1807_122
https://www.nxtbook.fr/newpress/jeccomposites/jcm1805_121
https://www.nxtbook.fr/newpress/jeccomposites/jcm1804_120
https://www.nxtbook.fr/newpress/jeccomposites/jcm1803_119
https://www.nxtbook.fr/newpress/jeccomposites/jcm1802_119-Supplement_Innovation_Report
https://www.nxtbook.fr/newpress/jeccomposites/jcm1801_118
https://www.nxtbook.fr/newpress/jeccomposites/jcm1711_117
https://www.nxtbook.fr/newpress/jeccomposites/jcm1710_116
https://www.nxtbook.fr/newpress/jeccomposites/jcm1708_115
https://www.nxtbook.fr/newpress/jeccomposites/jcm1707_114
https://www.nxtbook.fr/newpress/jeccomposites/jcm1706_113
https://www.nxtbook.fr/newpress/jeccomposites/jcm1704_112
https://www.nxtbook.fr/newpress/jeccomposites/jcm1703_111
https://www.nxtbook.fr/newpress/jeccomposites/jcm1701_110
https://www.nxtbook.fr/newpress/jeccomposites/jcm1611_109
https://www.nxtbook.fr/newpress/jeccomposites/jcm1610_108
https://www.nxtbook.fr/newpress/jeccomposites/jcm1608_107
https://www.nxtbook.fr/newpress/jeccomposites/jcm1607_106
https://www.nxtbook.fr/newpress/jeccomposites/jcm1605_105
https://www.nxtbook.fr/newpress/jeccomposites/jcm1604_104
https://www.nxtbook.fr/newpress/jeccomposites/jcm1603_103
https://www.nxtbook.fr/newpress/jeccomposites/jcm1601_102
https://www.nxtbook.fr/newpress/jeccomposites/jcm1511_101
https://www.nxtbook.fr/newpress/jeccomposites/jcm1510_100
https://www.nxtbook.fr/newpress/jeccomposites/jcm1509_99
https://www.nxtbook.fr/newpress/jeccomposites/jcm1507_98
https://www.nxtbook.fr/newpress/jeccomposites/jcm1505_97
https://www.nxtbook.fr/newpress/jeccomposites/jcm1504_96
https://www.nxtbook.com/newpress/jeccomposites/jcm1503_95
https://www.nxtbook.com/newpress/jeccomposites/jcm1501_94
https://www.nxtbook.com/newpress/jeccomposites/jcm1412_93
https://www.nxtbook.com/newpress/jeccomposites/jcm1410_92
https://www.nxtbook.com/newpress/jeccomposites/jcm1409_91
https://www.nxtbook.com/newpress/jeccomposites/jcm1406_90
https://www.nxtbook.com/newpress/jeccomposites/jcm1405_89
https://www.nxtbook.com/newpress/jeccomposites/jcm1404_88
https://www.nxtbook.com/newpress/jeccomposites/jcm1403_87
https://www.nxtbook.com/newpress/jeccomposites/jcm1401_86
https://www.nxtbook.com/newpress/jeccomposites/jcm1311_85
https://www.nxtbook.com/newpress/jeccomposites/jcm1310_84
https://www.nxtbook.com/newpress/jeccomposites/jcm1308_83
https://www.nxtbook.com/newpress/jeccomposites/jcm1307_82
https://www.nxtbook.com/newpress/jeccomposites/jcm1305_81
https://www.nxtbook.com/newpress/jeccomposites/jcm1304_80
https://www.nxtbook.com/newpress/jeccomposites/jcm1303_79
https://www.nxtbook.com/newpress/jeccomposites/jcm1301_78
https://www.nxtbook.com/newpress/jeccomposites/jcm1212_77
https://www.nxtbook.com/newpress/jeccomposites/jcm1210_76
https://www.nxtbook.com/newpress/jeccomposites/jcm1208_75
https://www.nxtbook.com/newpress/jeccomposites/jcm1207_74
https://www.nxtbook.com/newpress/jeccomposites/jcm1206_73
https://www.nxtbook.com/newpress/jeccomposites/jcm1204_72
https://www.nxtbook.com/newpress/jeccomposites/jcm1203_71
https://www.nxtbook.com/newpress/jeccomposites/jcm1201_70
https://www.nxtbook.com/newpress/jeccomposites/jcm1111_69
https://www.nxtbook.com/newpress/jeccomposites/jcm1110_68
https://www.nxtbook.com/newpress/jeccomposites/jcm1108_67
https://www.nxtbook.com/newpress/jeccomposites/jcm1107_66
https://www.nxtbook.com/newpress/jeccomposites/jcm1105_65
https://www.nxtbook.com/newpress/jeccomposites/jcm1104_64
https://www.nxtbook.com/newpress/jeccomposites/jcm1103_63
https://www.nxtbook.com/newpress/jeccomposites/jcm1101_62
https://www.nxtbook.com/newpress/jeccomposites/jcm1011_61
https://www.nxtbook.com/newpress/jeccomposites/jcm1010_60
https://www.nxtbook.com/newpress/jeccomposites/jcm1009_59
https://www.nxtbook.com/newpress/jeccomposites/jcm1006_58
https://www.nxtbook.com/newpress/jeccomposites/jcm1005_57
https://www.nxtbook.com/newpress/jeccomposites/jcm1004_56
https://www.nxtbook.com/newpress/jeccomposites/jcm1003_55
https://www.nxtbook.com/newpress/jeccomposites/jcm1001_54
https://www.nxtbook.com/newpress/jeccomposites/jcm0911_53
https://www.nxtbook.com/newpress/jeccomposites/jcm0910_52
https://www.nxtbook.com/newpress/jeccomposites/jcm0909_51
https://www.nxtbook.com/newpress/jeccomposites/jcm0907-08_50
https://www.nxtbook.com/newpress/jeccomposites/jcm0906_49
https://www.nxtbook.com/newpress/jeccomposites/jcm0904_48
https://www.nxtbook.com/newpress/jeccomposites/jcm0903_47
https://www.nxtbook.com/newpress/jeccomposites/jcm0901_46
https://www.nxtbook.com/newpress/jeccomposites/jcm0811_45
https://www.nxtbook.com/newpress/jeccomposites/jcm0810_44
https://www.nxtbook.com/newpress/jeccomposites/jcm0809_43
https://www.nxtbook.com/newpress/jeccomposites/jcm0807_42
https://www.nxtbook.com/newpress/jeccomposites/jcm0806_41
https://www.nxtbook.com/newpress/jeccomposites/jcm0805_40
https://www.nxtbook.com/newpress/jeccomposites/jcm0803_39
https://www.nxtbook.com/newpress/jeccomposites/jcm0801_38
https://www.nxtbook.com/newpress/jeccomposites/jcm0712_37
https://www.nxtbook.com/newpress/jeccomposites/jcm0710_36
https://www.nxtbook.com/newpress/jeccomposites/jcm0709_35
https://www.nxtbook.com/newpress/jeccomposites/jcm0707_34
https://www.nxtbook.com/newpress/jeccomposites/jcm0706_33
https://www.nxtbookmedia.com