JEC COMPOSITES MAGAZINE - Issue #115 - August/September 2017 - 38

MARINE
sailmaking

Weight savings and durability
Incidence Sails, the leading French producer of sails made from composite
materials, has developed a new manufacturing process, for which it is
obtaining a patent.

l

ncidence Sails, a sailmaker near La
Rochelle, is both design/engineering
firm and manufacturer, and a heavy
user of composite materials. With around
a hundred employees, the medium-sized
French business made sales worth €14
million for the year 2016. For a long time
now, it has used the standard double
diaphragm deep drawing (D4) process
to make its sails. The process involves
sandwiching carbon, aramid or Vectran
prepreg fibres between two PET films.
(Incidence Sails recommends carbon
fibre for regatta boats, but Vectran for
racing boats.)
If the French sailmaker was going to hold
on to its market share, however, it needed
to innovate - so about a year and a half
ago, the company started using its D4
knowhow to develop a new filamentary
membrane called DFI®, for which it is
obtaining a patent.
20% more lightweight
In simple terms, the new process consists
of the automated layup of prepreg tapes,
rather than fibres, where the PET film is
replace by polymerized sheets of paper.
"This makes it possible to save 20% on
weight, since there are no longer any films
and, especially, the sail will last twice as
long," explains Pierre-Antoine Morvan,
the head of Research & Development
at Incidence Technologies, a subsidiary
created in 2013 to develop and produce
the company's innovative processes. The
PET films had an unfortunate tendency
to delaminate over time. The weight

38

saving is not insignificant, given that a
160-sq-metre sail on an IMOCA-class boat
in the Vendée Globe race can weigh 70-80
kilos. Of course, this new technology
comes with a price tag, since the DFI process costs 25% more than D4, but this effect
is offset by the durability. "Our customers
want the best existing technology, and in
general they have significant purchasing
power," says Mr. Morvan. It remains that
the primary reason for switching to DFI is
budgetary, although it also depends on the
boat's specific mission. "If you're talking
about cruise sailing, there is no need to
use composite sails," he continues. The
company estimates the market share for
composites at 40%, and it is rising steadily.
Aramid and UHMWPE
To enable the use of DFI, Incidence Sails
had to develop the production plant and
the CAD tools for defining the tape-laying
path. The tapes are made of aramid (20

A set of DFI sails on
a CNB76 (a superyacht
from the CNB shipyard
in Bordeaux).
Ensuring excellent
shape stability, the
filamentary membrane
by Incidence Sails is
lighter and stronger than
standard membranes.
©Nicolas Claris

	 jec composites magazine / N°115 August - September 2017

to 80%) and UHMWPE (20 to 80%).
The main suppliers are Teijin and DSM.
Since it is a thermoplastic technology,
there are no requirements for low-temperature storage, as is the case for carbon
prepregs.
To simulate and calculate the right placement for the composite tapes, Incidence
Technologies uses the SailPack-Aravanti
advanced Fluid Structure Interaction
(FSI) simulation software. The challenge
of DFI is a crucial one for Incidence
Sails: while its sails used to win regularly
in the Vendée Globe, boats equipped
with sails by the American company
North Sails won the last two times. Even
if the process is different, the purpose of
DFi is to compete with the sails manufactured by North Sails. There is some
score settling on the horizon!
More information :
www.incidence-sails.com
http://www.incidence-sails.com
Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #115 - August/September 2017
