Dacron Kevlar & Spectra Pentex Carbon Cuben Fiber
More materials can be found below.
Also, here are some terms we throw around at the loft. They may help you pick the best material for your sail.
Wovens are made by weaving threads over and under each other to produce the sail material. The tighter a sailcloth is woven, the better it will perform.
Laminates are layers of film, scrim, or taffeta that are glued together under incredibly high pressures to form a composite sail material. Composite fabrics are made from two or more constituent components.
Scrim is a grid of relatively large, unwoven, straight yarns. Scrims have little stretch parallel to the yarns but have no off-threadline integrity and are usually sandwiched between other layers of scrim in a composite fabric.
Film is an extruded sheet of isotropic plastic such as DuPont's Mylar® polyester film. Film's good properties are low stretch in every direction, contributing to bias stability, zero porosity, and a surface that adheres well to other elements in the laminating process. Film's weaknesses are low tear resistance and a tendency to shrink.
Taffeta is a woven substrate that makes up the outside of some laminates. Taffeta is usually made from polyester and adds to the durability and chafe resistance of the laminate.
The ability of a material to resist stretch is called the modulus. Laminates generally have higher modulus than wovens of the same material because the threads are pre-tensioned and lie straight inside the laminated film. The higher the modulus, the less stretch the material has. Modulus is generally expressed in grams of load per unit of stretch for a certain fiber weight.
Since fabric properties, especially stretch, are not isotropic, (that is, they vary with direction), fabric orientations are significant. The orientation across the width of a fabric is called the fill. The orientation along the length of a fabric is the warp. These terms come from the weavers' names for the two directions of thread in the loom. Orientations at a significant angle to the warp and fill, especially 45°, are called the bias.
Tenacity is the tensile stress at rupture expressed in grams force per denier. Tenacity relates to the breaking strength of fibers, and should not be confused with modulus, which relates more directly to a fiber's ability to resist stretch.
Denier is the weight in grams of a 9000-meter length of a given yarn. A higher denier signifies a heavier fiber.
Flex Strength is the ability of a fiber to retain its strength after being folded back and forth. Flex strength is commonly expressed as loss in breaking strength after flutter testing.
UV Resistance measures the effect of sunlight on cloth. UV resistance is usually expressed as the time it would take for a material exposed to sunlight to loose half of its breaking strength.
More Sail Materials
Nylon: Used to make the traditional woven spinnaker fabric, this material is very light weight, but not very stretch resistant. Nylon is manufactured in weights of .5 oz, 30/20, .75oz., 1.5 oz., and 2 oz.. Nylon is used to make spinnakers and asymmetrical spinnakers (Gennakers) because of its light weight and its good strength. It does not, however, have good resistance to stretch. The extra stretch of nylon is not a big a factor in downwind and reaching sails. Nylon is never used in mains and headsails. Within the last few years, North has developed a new Transpac spinnaker fabric, which is made from special small diameter polyester yarns. Transpac cloth stretches less than Nylon, but requires extra expertise in the manufacturing and design of the sails. Because the polyester cloth stretches less, a collapse with a Transpac spinnaker will produce a higher shock load on the rig when the sail refills. Nylon is more susceptible to UV and chemical degradation than polyester. It should never be washed with a chlorine bleach or rinsed in a swimming pool.
Technora®: Technora is an aramid developed as a reinforcement for drive belt applications. In sailcloth, it is dyed black to help its UV resistance. Technora has a modulus similar to Kevlar, slightly better abrasion resistance and is more expensive than Kevlar. Used alone or in composite laminate constructions, Technora is currently recommended as a durable alternative to sun sensitive Kevlar. Often used as a bias support in composite high modulus laminates.
Dyneema®: Dyneema, like Spectra, is a highly-processed polyethylene which offers good UV resistance, high theoretical initial modulus and superior breaking strength. It also shares Spectra's creep characteristics.
