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1. A 3DL™ sails
begins with a three dimensional CAD/CAE design file created by a North
Sails sail designer. North's proprietary design software creates a
custom "mold" file for each individual sail. Because a 3DL
sail stretches less than competing 2D paneled or “string”
sail for a given amount of yarn, North designers can more accurately
define the desired "flying shape" because the computer molded
shape is that much closer to the resultant flying shape. |
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2.
A sophisticated computer program reads the design file, then instructs
an articulating mold to assume the designed shape. Shown here is
the underside of a 3DL mold with actuators controlled by a highly
sophisticated computer program.
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3.
A pair of lasers mounted above the mold scans the mold surface to
ensure the accuracy of the shape within imperceptible tolerances.
Shown is digital output of laser scanning
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4.
After a base layer of Mylar film (made from Mylar sections joined
together with modest shaping to lie reasonably smoothly over the
3D surface of the mold) is draped over the mold and tensioned, a
6-axis fiber head suspended from a computer controlled overhead
gantry then applies structural yarn onto the surface of the base
film, precisely following the 3D curve of the mold surface. The
fiber head "draws" a pattern in yarn that matches anticipated
loads in the sail. All structural yarns are applied under uniform
tension and adhere to the surface of the film to ensure they remain
in place prior to being locked by the lamination. |
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5.
Once the yarns are laid, a second film is positioned on top of
the base film and yarn, tensioned, and then covered with a
large vacuum
bag that compresses the laminate at approximately 1,800 pounds
per square foot. This second film contains a secondary mapping
of yarns
to handle incedental loads off the primary load lines. |
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6.
The gantry head is then removed and replaced with a carbon element
heat “blanket” that cures the pressurized laminate by
imparting a carefully controlled amount of heat through the laminate.
This causes the laminate to conform tightly to the mold in a manner
similar to a shrink-wrapping process. After curing, the sail is
allowed to cure further for a full five days prior to shipping and/or
finishing. |
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7.
When the laminate has cured, corner reinforcements, bolt ropes,
batten pockets and protective patches are applied by experienced
sailmakers. Because of the inherent material efficiency of the 3DL
manufacturing process, a finished 3DL sail can be up to 20% lighter
than a conventional paneled or a “string” sail of equivalent
stretch. Or, it has a wider wind range (larger sweet spot) for a
given weight. |