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