Laminate system for a durable controlled modulus flexible membrane

Abstract

A fabric system for producing at least a woven fabric of controlled modulus or elongation in the MD or warp axis, has a core layer which is the main structural element, and may have one or more woven cover fabrics adhesively bonded with an off axis configuration to one or both sides of the core layer. In a preferred embodiment the core fabric is covered with at least one off axis fabric on both sides. The cover fabrics may also have resin or film top layers laminated or coated on their outside surfaces, for mechanical performance or UV protection or both.

Description

[0001] This application is a continuation of pending U.S. application Ser. No. 10 / 293,828 filed Nov. 13, 2002 which claims the benefit of U.S. Provisional Application No. 60 / 337,732 filed Nov. 13, 2001.FIELD OF INVENTION [0002] This invention relates to the construction of multi-layered, controlled modulus, special purpose fabrics, and in particular to woven fabrics of controlled modulus or elongation in the machine direction (MD) or warp axis, with covering layers bonded thereto in off axis configurations. BACKGROUND OF THE INVENTION [0003] The applications for flexible membranes in general include products such as sails, airfoil and wing systems, aircraft control surfaces, inflatable structures, airships, temporary shelters, liquid storage tanks, fuel tanks, flotation devices, seals and gaskets for aircraft surfaces, and door seals. Current materials in flexible membranes are based on the following techniques: [0004] Core structural fiberous components are made of bonded scrim fib...

AI Technical Summary

Problems solved by technology

These scrims are not generally of woven construction, and have very little structural integrity when the resin bonds have been broken.

In short this type of bonded scrim has little durability with out modification and the addition of other components.

Because the scrim core layer does not provide off thread line stiffness, additional elements are used in current systems.

The result of this dependence on film interlayer and adhesive is that these structures have overall durability that is limited to the properties of the film and the adhesives used.

The low to no twist yarn used in these scrims contributes to these adhesive failures.

Twist is a secondary process and adds cost.

Resin bonded membrane systems have a catastrophic failure mode.

In practice this is not possible, so adhesive bonding failures are a cause for premature and catastrophic failures.

Resin and films have limited properties relative to fiber.

Because of the high dependence on resin bonding, current products are limited in durability to the flex and adhesion of the bonding mechanisms.

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