GLOSSARY

Carbon Fibers
Originally limited in use to America's Cup sails due to its extreme sensitivity to flexing. In 2001, a more durable version of Carbon laminates was introduced successfully in offshore racing. This modification of Carbon laminates combines very low stretch with considerably more resistance to flexing, and has proven to be a more durable laminate than Kevlar for offshore racing sails.

(See our article on this new version of Carbon laminates in our learning center article:
Sailcloth Article
New Carbon Laminates vs. Kevlar Laminates 5/25/2001

Dacron
Trademark name for polyester fibers by DuPont. Dacron may be made in a variety of weaves and finishes for racing and cruising sails.

Dacron - MF (Medium Firm)
Woven Dacron impregnated with a medium firm finish is an excellent choice for extended durability while maintaining reasonablely low stretch. Woven Dacron sailcloth combines long term durability and performance for Daysailors and Cruising.

Dacron - VF (Very Firm)
Woven Dacron impregnated with a firm finish. Good for racing & performance cruising. Lower Stretch than MF Dacrons, and has good durability.

Dacron YT (Yarn Tempered)
Woven Dacron impregnated with a super stiff "coating. Lowest possible stretch for racing. Has excellent fatigue strength, but has low tear strength, and must be handeled with care, especially when new.

Dyneema / Spectra Fibers
Dyneema is a Trademark name for Spectra. These fibers have very low stretch and excellent resistance to flexing. However, they tend to “creep” when subjected to high loads for extended periods of time. Spectra/Dyneema fibers are also difficult to laminates, as the fibers are very smooth and slippery. Fabrics made from Spectra/Dyneema are extremely expensive, and are often limited to heavy woven sailcloth for superyachts.

Kevlar Fibers
Dupont's name for Aramid fiber. Kevlar laminates have low stretch, but they also have extreme sensitivity to UV exposure and flexing. Kevlar sailcloths have recently added UV blocking glues, or UV coatings to the films to provide some protection from Ultraviolet damage. However, when the Kevlar fibers in the laminate turn from gold to brown, they have lost as much as 50%, or more of their strength and flexibility.

In Europe a very similar fiber is called Twaron, and is essentially the same composition

Kevlar Style - Technora Fibers
A Japanese Aramid similar in Kevlar in properties, but black in color. It has excellent stretch properties, better flex reistance, and much better UV resistance than Kevlar. The downside is that it is considerably more expensive than Kevlar. Technora fibers are used in the Scrim that is part of the Graph-X Carbon Laminates made by Dimension Polyant.

Kevlar Style - Twaron
the European fiber used in Racing Sails. It is essentially the same composition as Dupont's Kevlar.

Pentex Laminate
Pentex is a trade mark name for Allied Signal's lower stretch version of polyester fiber. Pentex laminates are often the same construction as the Polyester versions. Pentex laminates have about 30% less stretch than the same Polyester constructions when new, but only 20%-25% less stretch after extended use.

Polyester Laminates
There are many variations of Polyester laminates. The racing versions utilize heavy deniers of Polyester fibers sandwiched between 2 layers of Mylar film. Cruising Polyester laminates often add a light Dacron Taffeta laminates externally on both sides of the laminates for added chafe and UV protection.

Taffeta
Taffetas are light woven polyester (Dacron) fabrics added to laminates to increase chafing durability and UV protection to the substrate fibers that carry most of the sail loads. Although Double taffeta Cruising Laminates are dipped in UV and mold resistant baths, they are more prone to mildew than single layer woven fabrics.

Vectran Fibers
Liquid Crystal fibers with extremely low stretch, and resistance to flex. They are primarily used in high performance offshore laminates due to their high cost. Vectran is extremely sensitive to UV exposure and must be protected by a UV treated taffeta on both sides of the laminate.