Titanium - Racing Mainsail
UK Sailmakers pioneered loadpath sails with the Tape-Drive® construction method three decades ago. In loadpath sails the aerodynamic loads are transferred from the sail’s cloth (usually a mylar film or skin) and seams to bundles of high strength yarns that run continuously between the corners of the sail.
Titanium® sails are made with a grid of continuous carbon loadpath yarns running unbroken between the three corners of the sail; those yarns are laminated between two layers of 3D-shaped film. In the Titanium construction process, the yarns are laid dry–without glue–to reduce weight and to prevent the carbon yarns from becoming brittle.
Furthermore, not coating the yarns with glue makes for lighter, more flexible, and more durable sails (by 15-30%), which makes happier foredeck teams and happier owners who are not replacing their misshaped and broken sails as often.
The outer mylar films are the epidermis of the Titanium sail that protect and hold all the layers together. Shiny and weatherproof on the outside, the black or grey PET skins are tacky on the inside from the copolymer coating; this holds the yarns and films in place until the final lamination has been completed.
The PET film is a key element to this sandwich: at only 1.3 micrometers thick, this material is incredibly tough; PET is most familiar for its use in plastic bottles and in some paper currencies; try tearing either of these apart. Sunlight and heat up to 50°C/120°F does nothing to PET, not even making it shrink like many similar materials.
The film-yarn-film layers are placed onto a variable geometry thermoform in which the sail is UV and heat bonded into one piece at 1 bar pressure under vacuum. The copolymer melts around the carbon fibers resulting in a whole that becomes substantially stronger than the sum of its parts.
Yes, there are seams in a Titanium sail, but they are there simply to shape the film layers. Unlike most high tech sails in which structural yarns only run the width of an individual panel, a Titanium sail’s continuous yarns eliminate seam loads, load-induced seam distortion, wrinkles, or worse yet, seam failure. Titanium sails are smooth and wrinkle free.
Extra Durability With Taffeta
While very strong, Titanium can be made more durable with the addition of a finely woven polyester taffeta layer laminated to both sides of the sail. The taffeta layers can add some strength to the sail, but the main benefit is to give the sail protection from abrasion, which is a great benefit for offshore racing. For Titanium sails, taffeta is only available in grey.