Sailcloth - Modern Fibers

Modern Fibers

The characteristics of a sail are due to design, construction and the attributes of the fibers, which are woven together to make the sail cloth. The following sections discuss the attributes of fibers assuming a good design and careful construction. There are six key factors in evaluating a fiber for suitability in weaving a sail-cloth:

• Modulus (of elasticity): elastic stretch resistance per cross sectional area of fibre, analogous to the stiffness in a spring. Higher is better for upwind sails.
• Tensile strength or tenacity: breaking strength, measured as a force per cross sectional area of fibre. Higher is better for sails.
• Creep, which describes the long term stretch of a fiber or fabric. A material with creep may have a superior modulus, but lose its shape over time.
• UV (ultra violet) Resistance: strength loss from exposure to the Sun’s UV rays measured by a standardized exposure test.
• Flex Loss: Strength lost due to bending, folding, or flogging, which is frequently measured with an industry standard 50 fold test.
• Cost of the material

There is no perfect solution since in most cases the increase of one attribute generally results in the decreased attractiveness of another. Reduced stretch generally also reduces the flexibility causing a trade-off of performance for durability. Solving both problems generally sends the price out of range for most sailors.