JEC COMPOSITES MAGAZINE - Issue #102 - January/February 2016 - 53

thermoplastic

Thermoplastic composites production
by room-temperature vacuum infusion
The CANOE technical platform recently produced the largest thermoplastic composite boat ever manufactured by vacuum-assisted resin
infusion at room temperature. This 9-metre long pirogue opens the
way to the production of large, recyclable composite parts with performance similar to epoxy but shorter cycle times.

ontinuous fibre-reinforced thermoplastics (CFR-TP) are gaining more
and more importance within the
composites industry due to their higher
performance and recyclability. However,
CFR-TP production generally involves
high-temperature moulding, which
requires expensive tooling and machines.
This is especially prohibitive for large
parts (> 4 m²) such as boat hulls or wind
blades. Moreover, among the engineering
thermoplastics that are cost-compatible
with these industries, the water uptake
of most of these polymers leads to poor
mechanical performance with time.

Thermoset-like processes
The new Elium® thermoplastic resin
developed by Arkema overcomes these
issues and makes it possible to mould
large parts with thermoset-like processes.
Its low viscosity at 20°C allows fast and
complete infusion without heating. No
post-curing is necessary for most applications, due to a high degree of conversion,
typically higher than 98%, achieved at
room temperature. Post-curing may be
recommended for high-end structural
parts to obtain maximum performance.

With mechanical properties similar to
epoxy, but higher toughness and shorter
production cycle times, the Elium® technology is mainly focused on structural
parts (Table 2).

Curing at room temperature
CANOE participated in the development of the Elium® technology, specifically providing composite know-how to

By
francK tiSon
compoSite project manager
canoe

scale-up the production of large parts.
The recent moulding of a 9-metre long
pirogue (a boat used in tropical regions)
demonstrates the effectiveness of this
technology. The pirogue is made of four
composite parts that were assembled
together by adhesive bonding: a hull, a
deck and two watertight bulkheads. All
of these parts and the four seatings were
bonded with AEC Polymers®' meth-

Tab. 1: Main properties of the Elium resin (source: Arkema)
Heat deflection temperature

109°C

ISO 75/A

Maximum continuous temperature service

85°C

Water uptake (8 days)

0,5%

ISO 62

0,065 mm/m/°C

ISO 2155-1

1,2 MPa.m0.5

ISO 13586

Coefficient of Linear Expansion
K1c, Fracture Toughness Stress Intensity

Tab. 2: Main properties of Elium®-based composites using plain weave glass fabric (source: Arkema)
Properties of a composite structural part

Value

ISO method

Tensile strength

557 MPa

527

Tensile modulus

27 GPa

527

Flexural strength

700 MPa

14125

Flexural modulus

27 GPa

14125

Compressive strength

347 MPa

14126

Compressive modulus

28 GPa

14126

In-plane shear modulus

5.600 MPa

14129

Charpy impact strength (un-notched)

206 kJ/m2

179/2D

No102 January - February 2016 / jec

composites magazine 53

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #102 - January/February 2016