Not applicable.
The present invention relates generally to fire resistant coatings, and more particularly to a fire resistant coating including an intumescent material, a support structure comprising a hot-melt yarn for supporting the intumescent material, and a related method.
Fire resistant coatings are useful for application to substrates to protect the substrate from extreme temperatures. The prior art teaches use of an intumescent fire resistant coating with a support structure.
Fire resistant coatings often include char-forming compositions. For example, U.S. Pat. No. 4,529,467, to Ward et al., teaches a fire resistant coating composition that produces a carbonaceous char. Intumescent coatings expand to form an insulating char structure upon exposure to sufficient heat. Intumescent coatings may swell to produce a char that is more than five times the original coating thickness. Such expansion, however, results in cracking and fissures in the coating structure, and often, separation of some or all of the coating from the substrate to be protected. To prevent the char from falling off the substrate to be protected, a support structure may be provided.
The differential temperature rise as a function of time across a sample substrate at specified conditions provides a measure of a coating's effectiveness in protecting a substrate from extreme temperatures.
U.S. Pat. No. 3,913,290, to Billing et al., describes an insulated reinforcement for use on structural members. The reinforcement is supported on the structural member and the fireproofing material placed thereabout. The reinforcement secures an insulation strip against the end of the structural flange. Fireproofing material is applied over the mesh and insulation strip to cover the flanges and webs of the structural member. The reinforcement may be constructed of a mesh-like member.
U.S. Pat. No. 5,443,991, to Boyd, Jr. et al., discloses a hybrid mesh fabric to reinforce char resulting from a fire and to prevent or reduce fissures in the mastic fire resistant coating. The '991 Patent describes a fabric containing a high-temperature fibrous material with interweaving of a less-expensive low-temperature fibrous material with the high temperature fiber.
U.S. Pat. No. 4,069,075, to Billings et al., describes a structural support for char residue derived from a char forming intumescent coating on a structural member. The structural support includes a fire resistant mesh member attached to the structural member. A char forming intumescent coating is applied to the structural member so as to substantially encapsulate the entire mesh member so that the char residue, when formed, encapsulates the mesh member and is anchored to the structural member thereby. The mesh member is a wire mesh or a mesh formed from another fire resistant material.
U.S. Pat. No. 5,580,648, to Castle et al., discloses reinforcement for mastic intumescent fire protection coatings comprising free-floating carbon mesh embedded in the coating, or optionally, using carbon mesh with mechanically attached reinforcements. The '648 Patent teaches use of carbon mesh as an alternative to more expensive and more rigid welded wire mesh.
A shortcoming of woven prior art support meshes for intumescent coatings is that the weave is fragile and therefore susceptible to structural degradation when draped about a substrate and/or when the intumescent coating material is applied to the mesh. In one aspect, the weave structure may be distorted wherein the mesh openings formed between the warp and weft yarns, which are consistent and regular in the mesh as woven, are disrupted, which leaves a support material having inconsistent and irregular mesh openings, which is undesirable.
Attempts have been made generally to alleviate or mitigate woven mesh instability. In U.S. Pat. No. 4,320,160, to Nishimura et al., bi-directional fabric reinforcement structure is disclosed. More recently, U.S. Patent Application Publications Nos. 2015/0167208, by Bischoff, and 2015/0126089, by Bischoff et al., disclose a reinforcing system for a woven fabric, wherein a reinforcing system 25 comprises weft threads 26 and warp threads 27.
While the prior art may provide some useful properties, there exists a need for a simpler woven mesh having a more stable structure. Embodiments of Applicants' invention comprise a reinforcing system comprising reinforcing threads oriented only in a single direction.
Embodiments of the present invention comprise a woven mesh comprising a high-temperature yarn positioned in the warp (continuous machine) direction, a high-temperature yarn positioned in the weft (cross machine) direction, and a hot-melt yarn intertwined with each warp-direction high-temperature yarn, wherein the hot-melt warp yarn and the high-temperature warp yarn alternate their side-by-side positioning with each high-temperature weft yarn insertion in a leno weave (also known as a gauze weave or cross weave), and wherein the woven mesh is heated during the weaving process whereby the hot-melt yarn surface is softened so that it adheres to the high-temperature warp yarn at contact points there between and adheres to the weft high-temperature yarns at each intersection there between. Embodiments of a method of applying an intumescent coating in conjunction with embodiments of woven meshes of the present invention are also disclosed.
For a more complete understanding of the exemplary embodiments, reference is now made to the following Description of Exemplary Embodiments of the Invention, taken in conjunction with the accompanying drawings, in which:
The exemplary embodiments are best understood by referring to the drawings with like numerals being used for like and corresponding parts of the various drawings. While components of embodiments of the invention are herein depicted in a vertical or horizontal orientation, such orientation is for illustration only and other orientations are contemplated.
Referring to
In the embodiment of
In the embodiment of
In one embodiment, warp yarns 6, which one skilled in the art might designate as “skeleton” or “doup” yarns, are longitudinally disposed twistingly around (intertwined with) warp yarns 4. In one embodiment, warp yarns 6 comprise a material having a relatively low melting point/range (temperature). In one embodiment, such low temperature warp yarns 6 have a melting temperature of about 280° F. to about 300° F. In one embodiment, warp yarns 6 comprise one or more thermoplastic materials, such as, but not limited to, polyamide (e.g., nylon), polyester, and polyether sulfone (PES). In one embodiment, warp yarns 6 comprise or be synthesized from one or more non-synthetic materials, such as, but not limited to, glass, fiber glass, polylactic acid (PLA). In one embodiment, warp yarns 6 consist essentially of one or more such materials having such a relatively low melting temperature.
Although in
Referring now to
In various embodiments, warp yarns 6 may comprise substantially round fibers, although the invention is not so limited and other shaped fibers may be employed. In this embodiment, the diameter of warp yarns 6A and 6B, which may be the same or different, is significantly smaller than the diameter of warp yarns 4A and 4B, although the invention is not so limited and other relative dimensions may be employed. In addition, relative spacing (frequency) of wrappings of warp yarns 6A or 6B around warp yarns 4A and 4B, respectively, may be varied as desired, and may be consistent or non-consistent within the woven mesh 100.
In various embodiments, weft yarns 2 and warp yarns 4 may comprise substantially round fibers, although the invention is not so limited and other shaped fibers may be employed. In the embodiment of
While the two-dimensional
In one embodiment, utilizing techniques known to those skilled in the art, weft yarns 2 are woven with warp yarns 4 and 6 to provide a woven mesh 100 as depicted in
In various embodiments, a woven mesh 100 may be produced by one skilled in the art on a standard rapier loom, although the invention is not so limited and other looms or weaving devices may be employed. In one embodiment, a rapier loom available from Lindauer DORNIER GmbH of Lindau, Germany may be utilized to produce a woven mesh 100.
In order to test the stability of an embodiment of a woven mesh 100 of the present invention, a sample of the woven mesh 100 was manipulated as follows:
A sample of woven mesh 100, having dimensions of about 5 inches in the warp yarn dimension and about 4 inches in the weft yarn direction, comprising weft yarns 2 and warp yarns 4 comprising 3K carbon fibers, 678 denier warp yarns 6 comprising polyamide (nylon), and comprising cells 8 having a substantially square geometry of about 10 millimeters by about 10 millimeters, was cut from a woven mesh 100 produced as described above. Terminal intertwined warp yarns 4 and 6 (item 30 in
As is known within the art, fire protection for substrates may be provided by first draping a substrate with a support structure (mesh material) and affixing the mesh thereto, and then impregnating the mesh with an intumescent fire resistant coating composition. Intumescent coatings are known in the art and are particularly useful in fire resistance. Intumescent coatings form a char when exposed to extreme heat. One example of such a coating composition may be obtained from Intumescent Associates Group (IAG), LLC, or Houston, Tex., as NanoChar®.
Referring to
In one embodiment, a layer of woven mesh 100 is then draped about the substrate 24, whereby the woven mesh 100 is affixed thereto by the adhesive material 20. Generally, the woven mesh application step comprises pressing woven mesh 100 to the adhesive 20 by a form of pressure, which may include by hand, trowel, roller, or the like. In one aspect, the mesh material forms a support structure on the substrate 24 with regard to the coating composition 22 to be applied.
In one embodiment, a quantity of an intumescent fire resistant coating composition 22 is then applied to the mesh-covered substrate 24, wherein the coating composition 22 is provided on and above the exteriorly facing surface of the woven mesh 100, as well as at least partially within the cells 8 of the woven mesh 100. Such application may be by conventional application steps, including brushing, troweling, spraying, rollering, and the like. The fire resistant coating step may be repeated if additional coating 22 is required. In one aspect, such coatings 22 typically possess properties that allow for at least partial solidification (hardening) of the coating composition 22 on/within the woven mesh 100, whereupon finishing materials (not shown) may be applied over the dried coating 22.
In one aspect, the cellular stability of woven mesh 100 minimizes deformation thereof during affixation of the woven mesh 100 to the substrate 24 and during provision of the coating composition 22 to the woven mesh 100. During exposure of the thus coated substrate to fire and/or extreme temperatures, the coating material 22 decomposes to form a protective char layer which at least partially protects the substrate 24 from thermal damage. With char formation, the protective coating 22 expands. The woven mesh 100 is particularly useful in relation to an intumescent fire resistant coating 22 as it expands in multiple directions to accommodate expansion of the protective coating 22 resulting from char formation. Woven mesh 100 thus assists in reducing cracking of the charred coating 22 and helps maintain adherence of the charred coating 22 to the substrate 24.
Referring now to
An embodiment of a method of utilizing embodiments of a woven mesh 100 of the present invention to provide heat/fire resistance to a substrate comprises the following steps:
An Adhesive Application Step of applying an adhesive material, such as adhesive material 20, to a substrate, such as substrate 24.
A Support Structure Application Step of draping a support structure, such as woven mesh 100, to the adhesive-covered substrate.
A Fire Resistant Coating Application Step of applying a fire resistant coating, such as intumescent coating composition 22, to the adhesive-and-support-structure-covered substrate.
The method described above is merely exemplary, and additional embodiments of providing heat and/or fire resistance to a substrate utilizing embodiments of a woven mesh 100 of the present invention consistent with the teachings herein may be employed. In addition, in other embodiments, one or more of these steps may be combined, repeated, re-ordered, or deleted, and/or additional steps may be added.
While the preferred embodiments of the invention have been described and illustrated, modifications thereof can be made by one skilled in the art without departing from the teachings of the invention. Descriptions of embodiments are exemplary and not limiting. The extent and scope of the invention is set forth in the appended claims and is intended to extend to equivalents thereof. The claims are incorporated into the specification. Disclosure of existing patents, publications, and known art are incorporated herein by reference to the extent required to provide details and understanding of the disclosure herein set forth.
This application is a continuation application of U.S. patent application Ser. No. 16/378,167, filed on Apr. 8, 2019, which application claims the benefit of U.S. Provisional Application No. 62/658,256, filed on Apr. 16, 2018, which applications are both incorporated herein by reference as if reproduced in full below.
Number | Date | Country | |
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62658256 | Apr 2018 | US |
Number | Date | Country | |
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Parent | 16378167 | Apr 2019 | US |
Child | 17894356 | US |