With respect to sail materials, the term Dacron® is commonly used to refer to a woven cloth made of polyester fibers. More correctly, Dacron® is a registered trademark of DuPont, and refers specifically to a DuPont developed polyester fiber.

In a similar manner, with respect to sail materials, the term Mylar® is commonly used to refer to a polyester film, and, again, Mylar® is a registered trademark of DuPont, and refers specifically to a DuPont developed polyester film.

There are basically two types of sail materials used in hang glider sails - woven polyester fabrics and composite laminated fabrics that use some combination of polyester film and polyester or other reinforcing fibers. Wills Wing primarily uses premium fabrics made by Dimension-Polyant, widely recognized as the leading sail cloth manufacturer in the world.

V170 4.0 Ounce Woven Polyester Fabric

This is the most basic, commonly used sailcloth. It forms essentially the entire sail on gliders like the Falcon, and is typically used in the bottom surface and mid-chord top surface of other model gliders. It comes in white and in colors, and it is a very tight weave of small diameter polyester fibers, which is subsequently "stabilized" by the hot-press impregnation of a polyester resin. The purpose of the resin impregnation is to provide "dimensional stability" which is the resistance to distortion or stretch of the material along the "bias" - in other words, at some angle to the two perpendicular directions of the threads that form the weave. This resistance to bias stretch is important in maintaining the aerodynamic shape originally designed into the sail, when the sail is placed under varying loads. The material is relatively light in weight, moderately elastic, and has good durability. It provides the best combination of light weight and durability in a sail with the best overall handling qualities, on those models where very high sail tensions are not required.

Try the Glider Color Selector to see colors and sail patterns.

205MT and 240MT

These are two heavier woven fabrics, which utilize a ripstop pattern of larger diameter fibers woven into the regular cloth. These materials come in white only, and are typically used on the trailing edge of higher performance gliders, or other gliders where the trailing edge is subject to higher loads. 205 MT, which has a weight of 4.9 ounces per sailmaker's yard, is the standard trailing edge fabric on the T2 and U2 and an option on the Sport 2. 240 MT, which has a weight of 5.7 ounces per sailmaker's yard, is the standard trailing edge fabric on the Falcon 3 Tandem. These fabrics provide greater durability and increased resistance to stretch under heavier loads, allowing for better control of spanwise twist on high performance gliders.

HYDRA-NET® 200

Hydra-net® is a trademark of Dimension-Polyant, and refers to a tightly woven high tenacity fabric with an integrated ripstop pattern of Spectra® fibers. The use of these Spectra® reinforcing fibers in a relatively light-weight cloth provides the structural performance and durability of a heavier cloth with the superior handling of a lighter weight material. Hydra-net 200 comes in white only, and is an upgrade option for the trailing edge panel or leading edge panel on the Sport 2, T2 and U2.

PX Polyester X-Ply Laminates and UVM and Other Laminates

These several of what are commonly called "Mylar®" sailcloth. They are not available in colors, and will be either "mostly clear" or white depending on cloth construction. Laminated sail materials using polyester film have been used for many years in hang glider sails. The original inspiration for the use of these fabrics was an attempt to achieve superior performance by using a lower stretch material that was still relatively light in weight. In high performance hang gliders, limiting spanwise twist is a key component of performance, and twist is generally controlled by sail tension. The disadvantages of the polyester film fabrics have been that the reduced elasticity under load has generally resulted in "stiffer," less responsive handling qualities, and that the polyester laminated fabrics have been, historically, not as durable or long lasting as woven fabrics. The current generation of laminated fabrics are vastly improved over those of even ten years ago, however it is still generally the case that a premium woven fabric will outlast even the best laminated materials.

Wills Wing Mylar Sailcloth Options for 2010

1) Materials Previously and Currently Available

PX10T – used in panel 1 and / or panel 4
(semi clear top layers with white taffeta backing)
5 layers-
¾ mil Mylar film,
polyester scrim (square heavy reinforcing)
polyester black X-ply at 6 degrees
¾ mil Mylar film
added layer of lightweight taffeta on the underside.
Weight about 230 gm/m^2

PX05T – used in panel 3 on U2’s and T2/T2C’s or Panel 1 on Sport 2’s
(semi clear top layers with white taffeta backing)
5 layers-
¾ mil Mylar film,
lighter weight polyester scrim (square reinforcing)
polyester black X-ply at 6 degrees
¾ mil Mylar film
added layer of lightweight taffeta on the underside.
Weight about 210 gm/m^2
PX10T on Panel 1 is no charge on U2 or T2/T2C.
The option upgrade price for a U2 or T2 with an all PX top surface is:
(There is no upgrade charge on a T2C.)

All Mylar top surface is not an available option on a Sport 2. Upgrade to PX05T on Panel 1 on a Sport 2 is a $75 option:

2) New Materials for 2010:

PX15T – Used on Panel 1 only
(semi clear top layers with white taffeta backing – similar appearance to PX10T shown above)
PX15T is the same as PX10T but with a heavier polyester scrim (square reinforcing).
Polyester Xply is at 6 degrees
Weight about 260 gm/m^2
Will be substituted for PX10T on Panel 1 on a T2 or T2C in 2010 at no extra charge.

UVM15TWHT – Used on Panel 1 only
(bright white in color - opaque)
UVM15TWHT is similar construction to PX15T but with a wider x-ply (white Xply fibers oriented at 30 degrees) and with the special UV Mylar film. Also has the titanium dioxide pigment which renders the material bright white in color and opaque.
Weight about 260 gm/m^2

Can be selected for Panel 1 on a U2 or T2 (not avail on Sport 2) for an upgrade charge:

No upgrade charge on T2C.

PE10 – Used on Panel 3 & 4 only – must be used on both 3&4 together
(grey in color, partly transparent – shown with red and white cloth underneath)
Same construction as PX10 (like PX10T but with no taffeta layer) but the fiber is ‘PEN’ which is twice as strong as the polyester fiber. (No UV protection).
Xply orientation is at 6 degrees
Weight about 180 gm/m^2 The weight savings is from not using taffeta.



The option upgrade price for a T2 or U2 (not available on a Sport 2)with PE10 in P3 and P4 is:

There is no upgrade charge on a T2C.

UVMPE10WHT- Used on Panel 3 & 4 only – must be used on both 3&4 together
(bright white in color - opaque)
Same as the PE10, but with the UV Mylar film and the titanium dioxide pigment.
Xply orientation is at 6 degrees
Weight about 180 gm/m^2



The option upgrade price for a T2 or U2 (not available on a Sport 2) with UVMPE10WHT in P3 and P4 is:

There is no upgrade charge on a T2C.

ODL06 (Technora) Used on Panel 3 & 4 only – must be used on both 3&4 together
(clear – transparent with large, black Technora fibers )
Same construction as PX10 (like PX10T but with no taffeta layer) but the fiber is Technora which is three times stronger than polyester fiber. (No UV protection).
Weight about 180 gm/m^2
Available only on the T2C – option upgrade price is $150.

3) Materials No Longer Available:

UVM10T
used in panel 1 and / or panel 4
(grey in color – opaque)
4 layers-
¾ mil UV Mylar film (derivative of normal Mylar film with a special, highly UV resistant molecular formula),
polyester scrim (square heavy reinforcing)
¾ mil UV Mylar film
added layer of lightweight taffeta on the underside.
Weight about 230 gm/m^2

UVM05T
used in panel 3 only
(grey in color – opaque)
4 layers-
¾ mil UV Mylar film
lighter weight polyester scrim (square reinforcing)
¾ mil UV Mylar film
added layer of lightweight taffeta on the underside.
Weight about 210 gm/m^2

UVM10T WHITE used in panel 1 and / or panel 4
(bright white in color - opaque)
Same as UVM10T (grey) but with titanium dioxide pigment which renders the material bright white in color and opaque.

Handling Considerations:
There is no dramatic difference in the handling among the different Mylar materials, and no dramatic difference even between the Mylar materials and woven materials like 205 MT and Hydranet. When there is a difference, the woven fabrics tend to have nicer handling than the Mylar fabrics, and the lighter weight Mylar fabrics used in panels 3 and 4 tend to have nicer handling than heavier weight Mylar fabrics. The lighter weight PE Mylar materials handle nicer than the PX10T and UVM10T materials, and UVM05T or PX05T in the P3 panel results in lighter handling than UVM10T or PX10T used in the P3 Panel.

Durability:
All Mylar materials are expected to be inferior in durability to woven materials. That said, the Mylar materials with UV protection will be the most durable Mylar materials. The recommended “top drawer” materials choice for a T2C (where all cloth upgrades except ODL06 are included, so price considerations are not a factor) is UVM15T WHITE in the P1 panel and UVMPE10 WHITE in the P3 and P4 panels. Any Wills Wing fabric with UVM in the name uses a special UV resistant Mylar film that is highly resistant to UV deterioration. Any of the Wills Wing UVM WHITE fabrics also include titanium dioxide in the fabric dye that offers addition UV protection to the underlying substrate fibers.

Performance Considerations:
For competition pilots, or any pilot who flies a high percentage of the time with the VG set at the tighter settings, the lowest stretch materials (the PE10, UVMPE10 WHITE and ODL06) provide the greatest reduction in twist and the highest performance. Mylar materials in general will exhibit lower elasticity and therefore lower twist than woven fabrics at tighter VG settings. At lower VG settings, there is no significant performance advantage based on sail materials selection.

Model Specific Recommendations:

T2/T2C:

UVM15T WHITE Panel #1 (leading edge)
UVMPE10 WHITE Panel #3 and #4 (top surface rear body)
Excellent UV resistance, durability, handling and performance.

U2:

Best combination of handling, performance and durability is obtained with an all woven top surface – Mylar does not provide any measurable performance increase and will have less durability.

Hydranet (or 205 MT) Panel #1 (leading edge)
V170 White Panel #3 (mid-chord)
Hydranet (or 205 MT) Panel #4 (trailing edge)

If selecting an all Mylar top surface, best material choice is:

PX10T Panel #1 (leading edge)
PX05T Panel #3 (mid-chord)
PX10T Panel #4 (trailing edge)

Sport 2:

Best handling is obtained with an all woven top surface of 170 - 200 weight material. Mylar, or heavier materials will not provide any measurable performance increase and Mylar materials will have less durability.

V170 White or Color or IU200 White Panel #1 (leading edge)
V170 White or Color Panel #3 (mid-chord)
V170 White or Color or IU200 White Panel #4 (trailing edge)

Heavier Materials on P#1 and / or P#4 will provide increased durability, at the likely expense of some degree of handling responsiveness.

Hydranet (or 205 MT) Panel #1 (leading edge)
V170 White Panel #3 (mid-chord)
Hydranet (or 205 MT) Panel #4 (trailing edge)

Last Modified: 17 August, 2010