Patent Application
20210277707
This application claims priority to and all benefit of U.S. Provisional Patent Application Ser. No. 62/447,573, filed Jan. 18, 2017, titled STRUCTURAL BONDING TAPE, the entire disclosure of which is fully incorporated herein by reference.
Structural glazing in building construction, for example, in window, window wall, curtainwall, storefront, custom windows, entrances or related facade fabrication and installation, typically involves use of structural silicone sealant or other structural bonding adhesives, injected or otherwise placed in a cavity formed, for example, by a fenestration panel, frame member, and a spacer component that maintains a predetermined gap (e.g., ¼ inch) between the fenestration panel and the frame member. The required curing time for this structural sealant has created fabrication schedule challenges in the construction industry.
The present application contemplates inventive structural bonding composites for bonding a surface of a building panel (e.g., a fenestration unit) to a surface of a framing member, while maintaining a predetermined (e.g., by industry standard) face clearance between the bonded surfaces.
Accordingly, in an exemplary embodiment of the present application, a glazing system includes a fenestration unit having opposed first and second major surfaces, a frame member having a first major surface facing the first major surface of the fenestration unit, and a structural bonding composite interposed between the first major surface of the frame member and the first major surface of the fenestration unit. The structural bonding composite includes a compressible base member having a first structural adhesive layer bonded to the first major surface of the frame member and a second structural adhesive layer opposite the first structural adhesive layer and bonded to the first major surface of the fenestration unit. The structural bonding composite independently provides a sufficient bond of the fenestration unit to the frame member without other fastening materials.
In another exemplary embodiment of the present application, a structural bonding composite includes a silicone base member, a first structural adhesive layer bonded to a first side of the base member, and a second structural adhesive layer bonded to a second side of the base member opposite the first side. The structural bonding composite has an uncompressed thickness, and includes a material of limited compressibility selected to limit a compressed thickness of the structural bonding composite to approximately ¼ inch.
In another exemplary embodiment of the present application, a method of installing a fenestration unit is contemplated. In the exemplary method, a frame member is provided having a first major surface with a structural bonding composite adhered to the first major surface. The structural bonding composite includes a polymeric base member, a first structural adhesive layer bonded to a first side of the base member and bonded to the first major surface of the frame member, and a second structural adhesive layer bonded to a second side of the base member opposite the first side. A first major surface of the fenestration unit is adhered to the second structural adhesive surface to permanently bond the fenestration unit to the frame member, wherein the structural bonding composite independently provides a sufficient bond of the fenestration unit to the frame member without other fastening materials.
In the accompanying drawings which are incorporated in and constitute a part of the specification, embodiments of the invention are illustrated, which, together with a general description of the invention given above, and the detailed description given below, serve to provide examples of the principles of this invention.
As described herein, when one or more components are described as being assembled, connected, joined, affixed, coupled, attached, or otherwise interconnected, such interconnection may be direct as between the components or may be indirect such as through the use of one or more intermediary components. Also as described herein, reference to a “member,” “component,” or “portion” shall not be limited to a single structural member, component, or element but can include an assembly of components, members or elements.
The Detailed Description merely describes exemplary embodiments and is not intended to limit the scope of the claims in any way. Indeed, the invention as claimed and described is broader than and unlimited by the exemplary embodiments, and the terms used in the claims have their full ordinary meaning. For example, while the specific embodiments described herein relate to structural bonding composites for use in fenestration systems (e.g., products including glass or other transparent or translucent materials, fixed or movable windows, opaque doors or panels, glazed doors or panels, skylights, sloped glazing, window walls, curtainwalls, storefronts, custom windows, entrances or facades), the inventive components, combinations, systems, and methods described herein may additionally or alternatively be applied to other types of bonding composites, other construction systems and assemblies, and other uses.
As used herein, “composites” may include structural glazing and insulated glass construction parts fabricated using one or more layers of compatible homogeneous polymeric materials that are assembled and cured in any suitable standard or customized geometric shape. Examples of composite materials include any one or more of: (a) extrusions including, for example, rubber extrusions and cellular rubber extrusions comprising polymers such as silicones, EPDM, neoprene etc.; (b) tapes including, for example, glazing tapes comprising polymers such as butyl, silicones, acrylates, and urethanes; (c) gaskets including, for example, compression gaskets comprising polymers such as butyl, silicones, acrylates, and urethanes; (d) foams including, for example, open cell and closed cell foams comprising polymers such as butyl, silicones, acrylates, and urethanes; and (e) other accessories such as wedges, pre-set spacers, weather stripping, shims comprised from polymers such as butyl, silicones, acrylates, and urethanes. A composite may additionally or alternatively include a base layer composite (e.g., any one or more of the examples described above), and a curable adhesive layer on one or more sides of the base layer.
In the illustrated embodiment, the exterior surface 11 of the fenestration unit 10 is defined by an outer pane 12 and the interior surface 13 of the fenestration unit is defined by an inner pane 14 separated from the outer pane by a spacer 17 and a secondary seal 18. In other embodiments (not shown), the fenestration unit may include a single pane defining both interior and exterior surfaces. The edge portion 15 of the fenestration unit 10 is spaced from an inner surface of a glazing pocket 25 in the frame member 20 by a setting block 39 or other spacer component for limiting longitudinal movement of the fenestration unit with respect to the frame member 20. As shown, the setting block 39 is provided with an outer projection 38 that engages the retaining surface 23 of the frame member 20 to align the setting block with the fenestration unit edge portion 15.
The interior seal arrangement 30 of the exemplary embodiment includes a structural bonding element 50 adhered between the retaining surface 23 of the interior stop 24 and the inner pane 14. A gasket 44 may be provided adjacent to the bonding element 50 to provide sealing reinforcement between the interior stop 24 and the inner pane 14. As shown, the gasket 44 may include a dart 46 or other such projection that interlocks with a corresponding slot or gasket raceway 26 in the frame member 20. In another embodiment, the interior stop may be provided as a removable stop (as known in the art), for example, to facilitate installation. The exterior seal arrangement 40 of the exemplary embodiment includes a suitable sealant 41, such as, for example, exterior “weather sealing” sealant materials.
In a conventional glazing system, the bonding element is a sealant (e.g., a silicone sealant or adhesive) that provides a permanent bond between the fenestration unit and the frame member. According to an exemplary aspect of the present application, the need for a sealant applied between the interior stop and the interior surface of the fenestration unit may be eliminated by utilizing a structural bonding composite having a thickness sufficient to maintain a predetermined (e.g., industry specified) face clearance (e.g., ¼ inch) which providing sufficient bonding tensile strength and shear strength to bond the fenestration unit to the frame member against longitudinal and lateral forces. Bonding tensile strength and shear strength properties may be in accordance with ASTM C1401, or any other appropriate industry standards. By excluding the conventional bonding element sealant from the bonded glazing assembly, wait times for sealant/adhesive are minimized, thereby improving fabrication schedules, manufacturing efficiency, and building project construction schedules for enclosing the structure. In one exemplary embodiment, a frame member may be provided with a structural bonding composite pre-applied to the frame member by a frame fabricator (e.g., with a release liner applied to the exposed adhesive layer) to eliminate this assembly step. In another exemplary embodiment, a frame member extrusion may be provided with a structural bonding composite pre-applied to the frame member extrusion (e.g., after painting or anodizing the extrusion), with the extrusion being provided to a fabricator to cut the extrusion with pre-applied bonding composite into desired lengths for frame fabrication. In such an arrangement, the bonding composite may be rated to withstand extreme high temperatures beyond the expected service temperatures (e.g., temperatures exceeding typical aluminum saw temperatures, for example, by about 200° F.), to withstand exposure to heat resulting from cutting the extrusion (e.g., with a chop saw).
In the illustrated embodiment, the base member 153 of the structural bonding composite 150 includes a material configured to provide compressibility and tensile and shear strength in a wide range of temperatures (e.g., about −40° F. to about 200° F.). The base member 153 may be a polymeric component (e.g., a polymer, reinforced polymer, or polymer composite). While many different materials and methods of construction may be utilized, in an exemplary embodiment, the base member may include one or more of a rubber (e.g., cross-linked rubber), open or closed cell foam, viscoelastic foam, or plastic material (e.g., constructed from urethane, acrylic, and/or silicone), and may be formed, for example, by molding, extrusion, machining, or 3D printing. The first and second adhesive layers 154, 155 are selected to provide superior bonding tensile strength to the fenestration unit surface material (e.g., glass, stone, metal panel etc.) and to the frame member material (e.g., metals such as aluminum of various finishes, or stainless steel). While many different materials may be utilized, in an exemplary embodiment, the adhesive layers may include one or more of acrylic and silicone. In an exemplary embodiment, for superior bonding tensile strength, the adhesive may undergo a curing reaction upon contact with the frame member material. This curing reaction may result in a viscoelastic polymer composition changing into a solid elastomeric adhesive. The curing reaction can be initiated in several different ways after contact with the frame member, including, for example, heating the adhesive composition, exposing the uncured material to an activating radiation source or electron beam energy, or allowing the ambient moisture to trigger the cure to form an adhesive layer with superior bonding tensile strength.
Currently available structural bonding tapes, such as, for example, VHB Tape products manufactured by 3M, ACX Plus bonding products manufactured by Tesa, and Gaska tape products, are limited in thickness (typically up to 0.09 inches thick), such that these bonding products are unable to adequately maintain industry specified glass face clearance requirements (e.g., a ¼ inch clearance requirement). In addition, these tape products employ a pressure-sensitive tape adhesive which might be employed in a film or a fibrous backing. This pressure sensitive adhesive often deteriorates during periods of storage and becomes soft and low in adhesive and cohesive strength when the tape product is stored in roll form. Merely providing similar bonding products having an increased thickness, with a deterioration in their cohesive strength with storage in the roll form, presents challenges with regard to limiting compression and expansion of the base material during wind loading, and supporting the bonding tape against shear forces, for example, due to thermal expansion and contraction or seismic activity. According to an inventive aspect of the present application, a structural bonding composite provided with a compressible base member sized to maintain adequate face clearance may additionally be provided with a reinforcement member secured to (e.g., encapsulated by, sandwiched between or attached to) the base member to maintain a predetermined thickness of the base member against compression applied to the sides of the base member (e.g., compression between the fenestration unit and the frame member). In the embodiment of
As shown in
Many different types of reinforcement members may be utilized with a structural bonding composite in accordance with the present application. In an exemplary embodiment, at least one reinforcement member may be disposed within the base member (e.g., encapsulated within or sandwiched between layers of the base member) to limit compression of the base member.
The base member 253 encapsulates a rigid plate, shim, or other such internal reinforcement member 258 extending along a length of the bonding composite 250. The shim 258 may be provided in a substantially or relatively incompressible material, such as, for example, EPDM, Silicone, PVC, or aluminum. The shim 258 may be provided with a thickness ts (e.g., approximately 20-30% of the composite thickness t, or about 0.03″ to 0.09″ for a composite having a thickness compression limit of ¼ inch) selected to effectively limit the compressed thickness of the bonding composite 250, for example, to a predetermined allowable compressed thickness t′ (e.g., corresponding to an industry specified face clearance, such as, for example, ¼ inch). The shim may be provided in any suitable cross-sectional shape, including, for example, rectangular, circular, oval, trapezoidal, and square. The shim 258 may be provided in a width w sufficient to maintain uniform compression of the composite (e.g., 60-100% of the composite width). Alternatively, as shown in
In an exemplary embodiment, the adhesive layers or coatings applied to the sides of a base layer of a structural bonding composite include one or more silicones. Silicones are synthetic polymeric materials that possess an extraordinarily wide range of physical properties. They can be low- or high-viscosity liquids, solid resins, or vulcanizable gums. They display an unusual combination of organic and inorganic chemical properties that are due to their unique molecular structure of alternating silicon and oxygen atoms shown below:
For superior bonding tensile strength, the silicone adhesive curing reaction will result in development of a “crosslinked” elastomer from relatively low molecular weight viscoelastic polymers by means of a chemical reaction that forms these crosslinks and effectively extends chain length after contact to the frame member material resulting in a superior bonding tensile strength. There are many types of curing silicones. Such systems may include (i) addition-cured, e.g., hydrosilylation cured (alternatively spelled “hydrosilation”) silicones, (ii) radiation cure silicone, and/or (iii) condensation-cured silicones.
Addition-cured silicones (e.g., hydrosilylation cured silicones) do not produce by-products during curing. An adhesive based on this cure system is of higher quality and more dimensionally stable, and are a more preferred cure system. The addition cured composition typically contains: (1) a polymer which contains two or more vinyl functional groups; (2) a “hydrosilane” crosslinker component containing two or more SiH bonds; and (3) a precious metal catalyst such as a platinum catalyst. An exemplary addition-cured silicone is formed by reacting (1) a multiply-vinyl-containing organopolysiloxane with (2) an organopolysiloxane containing a multiplicity of SiH bond per molecule. This reaction is typically facilitated by the presence of (3) a platinum catalyst of the Karstedt type.
Radiation cure silicones do not produce by-products during curing. An adhesive based on this cure system is of higher quality and more dimensionally stable, and are a more preferred cure system. The radiation-cured composition typically includes (1) silicone compounds exhibiting acrylic or epoxy functionality, or both, (2) a catalytic amount of a photoinitiator comprising an onium salt cationic photoinitiator or a silicone-soluble free-radical photoinitiator, or a mixture thereof, and (3) additives such as reactive diluents, tackifiers for superior bonding tensile strength.
Condensation-cured silicone adhesives cure a by-product such as water or alcohol while under-going the crosslinking reaction. Condensation cure is preferred as a secondary cure for the adhesive for superior bonding tensile strength.
In other embodiments, as shown in
In another exemplary embodiment, at least one reinforcement member may be bonded or otherwise attached to a lateral edge portion of the composite's base member. Any suitable bonding or attachment may be utilized, including, for example, at least one of acrylic and silicone.
The laterally bonded reinforcement member 458 of
In other embodiments, a structural bonding composite may utilize both an internal shim (or other such reinforcement member) and a laterally attached reinforcement member, for example, to provide additional reinforcement against compression of the composite's base member.
While various inventive aspects, concepts and features of the inventions may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the present inventions. Still further, while various alternative embodiments as to the various aspects, concepts and features of the inventions—such as alternative materials, structures, configurations, methods, circuits, devices and components, hardware, alternatives as to form, fit and function, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts or features into additional embodiments and uses within the scope of the present inventions even if such embodiments are not expressly disclosed herein. Additionally, even though some features, concepts or aspects of the inventions may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure, however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated. Moreover, while various aspects, features and concepts may be expressly identified herein as being inventive or forming part of an invention, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts and features that are fully described herein without being expressly identified as such or as part of a specific invention. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order that the steps are presented to be construed as required or necessary unless expressly so stated.
While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the invention to such detail. Additional advantages and modifications will readily appear to those skilled in the art. For example, the specific locations of the component connections and interplacements can be modified. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus, and illustrative examples shown and described. Accordingly, departures can be made from such details without departing from the spirit or scope of the applicant's general inventive concept.
This application is a continuation of U.S. application Ser. No. 16/478,332 filed on Jul. 7, 2019, titled STRUCTURAL BONDING COMPOSITE, which claims priority to and all benefit of U.S. Provisional Patent Application Ser. No. 62/447,573, filed Jan. 18, 2017, titled STRUCTURAL BONDING TAPE, the entire disclosures of each of which are fully incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62447573 | Jan 2017 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16478332 | Jul 2019 | US |
| Child | 17205252 | US |
