June 27, 2008



How FiberPath Works

Why have we developed FiberPath sails? The answer is that because the fibers in a FiberPath sail are aligned with the primary loads in the sail, and a FiberPath sail can be built with multiple fiber patterns to address secondary loads, a FiberPath sail has a wider range and is stronger for its weight than a tri-radial sail. The trouble with tri-radial sails is they only cover primary loads. Because the fibers in FiberPath sails run on top of each other in different directions, specific loads in each area of the sail can be handled.

With FiberPath technology we can build true load-path sails with proven fast shapes and the right combination of fibers and films for each application.

Cost of a FiberPath Sail vs. a Tri-Radial Sail

The average cost of a FiberPath sail is anywhere from the same as a paneled sail to 10% higher. When we reach full production we hope to be able to deliver FiberPath sails at a lower price than tri-radial sails—that's the goal, to make less expensive sails! The reason this is possible is that we are buying raw product by the pound rather than buying finished sailcloth by the yard—raw materials are amazingly inexpensive.

FiberPath Speed

Perhaps the best aspect of FiberPath sails is that because the sails are crosscut (FiberPath panels are 50 inches (1.27 meters) wide), we can transfer our existing sail designs and broadseam shaping directly to FiberPath and produce sail shapes that are already proven to be fast. We use a special program to specify the "fiber stringing"—the mapping out of the fiber layout of each sail. and The seams are joined using DIMENSION-POLYANT's UltraBond system, so seam creep is eliminated (the seams are actually the strongest part of a FiberPath sail).

FiberPath Performance Life & Longevity

A FiberPath sail will hold its performance shape 1 ½ to 2 times longer than a tri-radial sail, because in a tri-radial sail it is the secondary loads and Mylar shrinkage that ruin the shape. FiberPath sails stay fast longer because the secondary loads are addressed, but the shrinkage issue is the same as that of a tri-radial sail. Of course, in addition to their high-tech, load-path look (you can hardly see the panels), compared to paneled sails FiberPath sails show an increased smoothness—a result of the vastly reduced number of panels and sections.

FiberPath Wind Range

The range of a FiberPath sail is wider than a tri-radial sail; a FiberPath sail is also easier to use because it needs less sheet adjustment through the wind range. Because the secondary loads are handled by the fiber layout, a FiberPath sail keeps its designed shape throughout the wind range. And a FiberPath sail is lighter than a tri-radial sail built for the same application. For example, to make a FiberPath sail heavy enough to meet the class minimum weight for a Melges 24 jib would mean packing a redundant amount of fiber into the sail—that's how weight-efficient FiberPath is compared to a paneled sail!

FiberPath Fiber Choices

FiberPath is available with Carbon, Technora or Kevlar fibers. Technora is an aramid, and for longevity reasons we prefer it to Kevlar; given the same size fiber, Technora about 10% stronger than Kevlar, but after six months of use Technora is probably 2 ½ times better than Kevlar—because Kevlar suffers UV degradation and Technora doesn't.

Whether Technora or Carbon, the fiber deniers (size) in a FiberPath sail can be varied or kept uniform, and the fibers are laid down in groups of four. We can make multiple passes of fiber and vary the angles in any direction. We are careful, though, to avoid placing too much fiber in one area (such as making a clew too thick), to avoid a delamination problem.

FiberPath Carbon sails are quite different than the current carbon laminate sailcloths, which use big bundles of carbon (necessary from a production standpoint to avoid brittleness). FiberPath Carbon sails have fiber bundles that are maybe one-tenth the size of carbon sailcloth bundles, and there are many, many more bundles in FiberPath—which from an engineering standpoint is a much better way to go.

FiberPath Film & Taffeta Choices

FiberPath sails use either clear Mylar (polyester) film or a tinted (UV) film (recommended for Kevlar). The scrim in FiberPath is Technora in both directions, chosen for its toughness and superior UV properties. (The scrim's role is, if the sail is punctured, to prevent the tear from following the primary threads and continuing to rip.) FiberPath cruising sails, with a taffeta for durability, are in development.

The FiberPath Laminate

We believe the FiberPath lamination process is superior to vacuum-formed laminates, for several reasons. FiberPath panels are formed under extremely high pressure between the hot-oil-filled calendar rolls of a laminator, which is exactly the way commercial sailcloth makers build their sailcloth laminates. While laminates such as 3DL are formed using vacuum pressure (1 atmosphere), FiberPath laminates are formed with the equivalent of 10 atmospheres—ten times the pressure. "Vacuum bagged" laminates must rely on a relatively high amount of glue to hold everything together—and in terms of stretch, glue is dead weight. FiberPath laminates require only a minimum amount of glue to achieve a reliably tough bond between Mylar, fiber, and scrim, and the lamination process produces a consistent bond throughout the panel, time after time.