The radial cut makes possible to produce sails that are lighter and more dimensionally stable than Cross Cut ones.
Warp oriented fabrics.
In the radial panels, the cloth yarns and the seams are oriented along the load path lines of the sail and the warp yarns are taking most of the strain. The requirements of fabrics suitable for the radial cut are different from those used in traditional crosscut.
Recently, cloth manufacturers have developed a new special weave which greatly reduces the initial stretch caused by the yarn crimp, typical of "strong warp" sailcloth.This fabric is offered by Dimension Polyant under the name of Pro Radial (PR). It is suitable for all sails (except of course gennakers and spinnakers) and achieves a very long service life.
Mixed yarn fabrics
Hybrid fabrics in which polyester fibers are interwoven with high modulus polyethylene (UHMWPE) have the longest life among sail materials. Hybrid fabrics however cannot shrink evenly when heat set, so, for better diagonal stability, yarns are mechanically roughened before weaving and receiving the resin coating. The special weave of Dimension/Polyant's HydraNet Radial (HNR) has been developed for radial application.
Laminates.
Laminates are sail materials where the structural yarns are encapsulated between two films. These films are mostly made of polyester, with DuPont's "Mylar" being the universally known one. Films can also be coupled with a so-called taffeta (light polyester) fabric from the outside for a longer service life. Sometimes this takes the form on a non-woven cloth, called by Dimension/Polyant "Liteskin" .The external taffeta fabric works as a shield and provides better abrasion protection.
The way laminates are built makes it heavier compared to woven fabrics, on whose they have the advantage of a greater bias stability provided by the films. The structural yarns can be made from different fibers. For cruising sails polyester or polyethylene make the most sense because they don't suffer of carbon's fragility and aramid UV sensitiveness.
OneSails fabrics:
OneSails recommends fabric for the production of triradial sails, which have been specially developed for this cut. HydraNet Radial, polyester/UHMWPE hybrid, has been on the market for 20 years and has more than proven itself for high mileage cruisers. It is the first choice for circumnavigators and those who expect the maximum life from their sails. Alternatively, we use ProRadial, which is 100% polyester and has a similar special weave.
Suitable for:
cruisers looking for a good compromise of long lasting and shape holding.