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"We are always on the look-out for the magical fibre"

An interview with Gautier Sergent, Head of R&D for North Sails, world leader in composite sails.
"We are always on the look-out for the magical fibre"

Your career at North Sails in a few words?

After spending close to 10 years at North Sails New Zealand following an end-of-studies internship as part of an engineering degree, I completed my training with a Master's degree in Sail Physics. This provided me with the opportunity to discover the world of offshore racing and in particular the Volvo Ocean Race for which North Sails became the official exclusive supplier. I also had the opportunity to take part in the America’s Cup with Oracle. In 2010, I returned to France to work on Franck Cammas' Groupama project for Volvo. In 2014, I began managing the 3D-moulded sails production sites in the USA. I returned to France two months ago to structure and lead the R&D unit.

Why has North Sails always been at the forefront of innovation?

A pioneer in the manufacture of composite sails using 3DL technology, the American North Sails company is a world leader with a 50% share in the sails market and a dominating position is races and regattas. At the time of its creation in the late 1950s, Lowell North, the company's founder, had, in the wake of Ted Hood, been able to master the manufacture of Dacron which is a woven polyester. By adding melamine and using heat treatments, he was able to develop a more stable fabric which reduced the deformations in the sails and enabled the manufacturing process to be reproduced without losing any quality. This was to be the first in a long series of innovations.


Which new manufacturing techniques appeared in the 1980s?

It was in the early 1980s that Kevlar-based laminated fabrics (aramid) and fibres sandwiched between two films of PET (Mylar) began to appear. These new manufacturing techniques enabled designers to create sails with radial cuts (and no longer horizontal cuts) and thus to create panels oriented in the direction of the efforts in order to gain in performance. Unfortunately, these gains in stability were detrimental to the lifespan of the sails due to the laminated fabrics' sensitivity to UV rays and the deterioration of the adhesive over time.


Was the 3DL technology a major innovation?

In the early 1990s, the 3DL technology used the principle of tri-radial sails made from laminated fabrics. The major difference came from the fact that they were manufactured on an adjustable mould that faithfully reproduced the design created by a numerically controlled machine, functioning in the same way as a 3D printer. The mould is then draped with a Mylar film and a head deposits the threads continuously from one point to the next. This process served to eliminate seams and improved control over the shape and the weight/elongation ratio. Thanks to moulding, which replaced manual assembly, it became possible to replicate sails ad infinitum.

Was the 3Di technology another major innovation in 2010?

At that time, and after having successfully tested in a racing situation on a ship in the America’s Cup, North Sails began selling the 3Di technology. Compared to previous high-performance sail manufacturing techniques, this filament-based composite technology had multiple advantages: no more risk of delamination, greater resistance to UV rays, a more stable profile with equivalent materials, the initial shape of the sail maintained for longer periods of time. This was a composite technology through which filaments were draped on a mould, side by side, on strips. This process allowed for a more fundamental mix of the very high performance polyethylene fibres Dyneema and Spectra. These fibres, which are highly resistant to bending and abrasion, complement the other extremely resistant but more fragile polyamide and/or carbon fibres.

The process made it possible to make use of the best of both worlds and to create a material with exceptional properties whose integrity only deteriorated slightly over time.

Are these technologies useful for amateur sailors?

This technology was particularly useful for large cruise ships. As it was improved over the years, it was then made available to the general public in various forms. The latest innovation implemented in June 2017 was the introduction of polyester in this 3D composite technology, which improved its abilities to retain its shape while significantly reducing costs (50% cheaper than very high ranges made from carbon).




Which direction will your research take?

We still have a lot of progress to make regarding the optimisation of our composite process and combining the fibre filaments. There is also much work to be done in the area of adhesives and resins. In order to continue to master our implementation processes, we are designing our own machinery and are working closely with very high performance resin and fibre suppliers. Although we actively contribute to the attractiveness of their products, we are just a small cog in their machine, and we sometimes have trouble explaining our specific issues which are often very different from those of their other customers.

What kind of resources do you have access to for your R&D work?

We have a laboratory equipped with testing machines to reproduce the stresses placed on the sails. We place sensors on the sails to measure the durations of the loads, the frequencies of wind loads. In the absence of standard tests and well-defined protocols, our aim is to be able to fine-tune our materials internally as much as possible.



Will we be seeing new materials in the near future?

For the existing and fairly recent technology, we are working on overcoming the contraction issues experienced with polyethylene which cause premature ageing of the sail. With our suppliers, we are on the look-out for a magical fibre that would have the properties of polyethylene without this particular disadvantage. I do not believe that we will be seeing any revolutionary materials in the next five years, although much hope is being pinned on graphene, a form of carbon which is still in its infancy.

© North Sails


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