CUBEN FIBER SAILS...super-light, super-strong fabrics for downwind sails


The Cuben Fiber laminate consists of filament tapes (Dyneema, aramid or carbon yarn spread flattened out into a single filament layer) between outer layers of polyester or fluoride film.© North SailsCuben Fiber is a proprietary laminated sailcloth manufactured by North Cloth in which fiber that is originally manufactured as a yarn (many small filaments bundled together in a larger thread) is spread into a flat tape of sideby- side filaments. Cuben Fiber tapes are typically produced from Dyneema (Spectra), but are sometimes made using other fiber types such as carbon and aramid. These tapes are arranged in various layouts and combinations between outer layers of film (see diagram). Films used in Cuben Fiber sailcloth include polyester (“Mylar”), which is referred to as “K” type, or Fluoride “FC” type film. The Cuben Fiber laminate is autoclaved to ensure that it's extremely well consolidated and as light as possible.

Cuben Fiber looks different from the usual taffeta or scrim based laminated cloth. It’s distinctive mottled grey color (other colors are available on a custom order basis) give it a high-tech appearance. Cuben Fiber is very strong for its weight. Because the fiber tapes can be laid up in varying directions, strength performance can be enhanced in warp, fill and intermediate directions.

Cuben Fiber is produced in a wide variety of film and tape combinations:

• K-Type polyester films are well suited for use in lighter Cuben Fiber styles.

• FC-type Fluoride films are often preferred to polyester in middle and heavy weight Cuben Fiber materials.

• Cuben Fiber HB styles are laminated with extra plies of filament tape in the intermediate directions between warp (0 degrees) and fill (90 degrees). HB styles most often feature plies in the +/- 30 degree directions, with some special styles also featuring plies at +/- 6 degrees. For heavier load applications, HB is advisable.

© North Sails

Cuben Fiber gives North sail designers the opportunity to design very light and easily pressurized sails with enough strength to handle high shock loads. There is no other lightweight sail material in the world that offers the strength needed to absorb the energy of an asymmetric sail refilling after a gybe, or the loads generated when sailing in lumpy seas. Super light Cuben Fiber styles weigh 33-50% less than the lightest coated nylon spinnaker cloths. A Cuben Fiber asymmetric spinnaker will stay pressurized and will load the spinnaker sheet at significantly lower apparent wind angles than any other material, providing a significant net VMG gain. The advantage is most pronounced in small-medium size boats where “traditional” spinnaker fabrics are tend to be somewhat overweight by nature.

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