Giving up the weave

Non-woven external finishes have moved into mainstream sailmaking…

Sailcloth has gone through multiple iterations over the years. Woven polyester long ago gave way to high-tech laminates and composites that offer tremendous weight to strength performance. While the fibres that provide this strength vary in modulus, flex, UV and tensile strength, most laminates are still dependent on standard polyester films that encapsulate the fibres and provide off-angle stability. Polyester films have been the primary base since the late 1970s but gradually sailmakers have recognised that these films aren’t as long lived as the fibres they protect and support.

Over time polyester films may succumb to UV degradation and abrasion which can break the windows between the fibres, while longterm off-angle loading can cause the films to shrink. One means to minimise ageing is by adding a layer of fabric to the outer film, providing a UV-stable surface that offers more off-angle stability and enhances abrasion resistance. This type of fabric has been in use in cruise laminates for years and provides incredibly long-lived sails. The one drawback, of course, is the increased weight incurred with the added taffeta.

In close up (below) and definitely in action (main picture), the new Lite Skin taffeta has been given a tough workout in the last six months on the radically reworked supermaxi CQS – which has enjoyed its fair share of drama through a very busy offshore programme. In spite of being lighter than previous taffetas the sails came through in good shape … literally

To address this issue Dimension-Polyant (DP), the market leader in laminated roll goods, began to look into other industries for taffetas that would provide the requisite abrasion and UV properties while minimising additional weight. DP narrowed down the possibilities, zeroing in on a unique family of taffetas, branded as Lite Skin. Lite Skin is a non-woven taffeta utilising a balanced fibre count of very small-denier polyester splayed down to filament form on both the warp and fill. The filaments are then nipped together on a high-pressure calendar to form a stable lightweight sheet. While DP are currently working with four different weights of Lite Skin, the standard weight is about 30 per cent lighter than comparable woven taffetas. The flatter profile of the filament construction also provides a very smooth surface that has proved to be less susceptible to abrasion than standard woven products.

While the actual weight savings of the Lite Skin compared with woven taffetas seem significant, it’s the stability of the Lite Skin that makes it unique. Testing shows that initial stretch in off-angle loading is greatly enhanced, providing a more balanced base with increased tear strength. The majority of roll products on the market contain a total of 1.5mm of polyester film. With the added stability of the Lite Skin, DP have decreased film content by 33 per cent, eliminating weight without giving up performance, while at the same time producing a more pliable fabric for ease in sail handling. Adhesion of the filaments to the films provides a more even distribution of fibre contact to the film, giving the product a softer ‘hand’. Most significantly, Lite Skin reduces the shrinkage associated with laminate sails, eliminating creasing from folding and fluttering to maintain the designed shape whether racing or cruising.

Introducing a unique fabric like Lite Skin to the marine environment requires precautions. Mildew and UV are major issues with any laminated fabric. DP have addressed mildew by adding antimicrobial blockers in every layer, with all film/film and film/ taffeta bonds being treated. The filament construction retains less moisture than spun fibre so Lite Skin dries more quickly than woven taffetas, minimising the moisture pick-up necessary for mildew growth. More protection is provided by DP’s UVt top coating, a blend of UV inhibitors and supplementary antimicrobial additives to further inhibit mildew growth while ensuring maximum UV protection.

Performance and feedback have been exceptional. Initial applications were in single-sided membrane use, with one of the first suits of sails winning the J-111 North Americans. From this Lite Skin has gone into multiple grand prix and maxi projects, in some cases utilising DP’s ability to colour the product for marketing or cosmetic purposes. In double-sided application to the GPL GraphX Performance Carbon line and the Carbon Sport Recreational line Lite Skin is dominating all other roll goods and proving to be excellent in durability and performance. Different weights of the Lite Skin family of taffetas will be going into larger superyacht applications and lighter performance needs.

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