Multi-Pane Insulating Glass Unit Having a Rigid Frame for a Third Pane and Method of Making the Same

Abstract

An insulating glass unit and a method of forming same comprising a pair of glass panes in a parallel, spaced apart relation, at least one edge spacer and at least a primary sealant7 glass panes, said at least one transparent film secured to one of a support structure and the at least one edge spacer, wherein the film is positioned in a spaced apart parallel relationship between the pair of glass panes, and wherein the film is heat shrunk to a tensioned state prior to positioning of the film between the pair of glass panes.

Claims

1. An insulating glass unit comprising: a pair of glass panes in a parallel, spaced apart relation; at least one edge spacer and at least a primary sealant located between adjacent edges of the pair of panes to provide an integral sealed unit defining a space therebetween; and at least one transparent film located within the space between the pair of glass panes, said at least one transparent film secured to one of a support structure and the at least one edge spacer, wherein the film is positioned in a spaced apart parallel relationship between the pair of glass panes, and wherein the film is tensioned prior to positioning of the film between the pair of glass panes.

2. The insulating glass unit of claim 1, wherein the at least one transparent film is supported by the support structure and the support structure is separate from the edge spacer.

3. The insulating glass unit of claim 2, wherein the support structure comprises a plurality of frame members located adjacent an edge of the film.

4. The insulating glass unit of claim 3, wherein the plurality of frame members are rigid and each are made of rigid solid or hollow profiles such as rigid aluminum profiles.

5. The insulating glass unit of claim 2, wherein the film is annealed prior to or after securing the film to the support structure.

6. The insulating glass unit of claim 1, wherein the tensioned state of the film has a tension of less than or equal to 1.5 lb. per linear inch.

7. The insulating glass unit of claim 1, wherein the film is heated to an annealing temperature of at least 100° C. for less than or equal to one minute.

8. The insulating glass unit of claim 1, wherein the film comprises at least one of a polymeric sheet, a thin glass sheet, and any other transparent sheet.

9. The insulating glass unit of claim 8, wherein the film is a polymeric sheet comprising polyethylene terephthalate.

10. The insulating glass unit of claim 1, wherein the film is secured to the support structure or the at least one edge spacer by at least one of a mechanical member, an adhesive, the primary sealant, or by thermoplastic welding.

11. The insulating glass unit of claim 2, wherein the support structure is secured to the edge spacer.

12. The insulating glass unit of claim 2, wherein the pair of glass panes comprises a first glass pane and a second glass pane and wherein the support structure is configured to allow for a gas to travel between a first chamber located between the first glass pane and a first side of the film and a second chamber located between the second glass pane and a second side of the film to ensure pressure equalization between the first chamber and the second chamber.

13. The insulating glass unit of claim 1, wherein the film includes at least one of materials embedded therein or coated on one or both sides to control transmission and/or reflection spectra.

14. A method for forming an insulating glass unit comprising: providing a pair of glass panes in a parallel, spaced apart relation; providing at least one film; stretching the film to remove wrinkles; securing the film to one of a support structure; applying heat to the film to shrink the film, wherein the step of annealing the film occurs after the step of securing the film to one of the support structure; positioning the film secured to one of the support structure between the pair of glass panes such that the film is positioned in a spaced apart parallel relationship between the pair of glass panes; and providing the at least one edge spacer and a primary sealant between adjacent edges of the pair of panes to provide an integral sealed unit defining a space therebetween.

15. The method of claim 14, wherein the film is secured to the support structure, and the film and the support structure are positioned between the pair of glass panes at a location that is separate from the at least one edge spacer.

16. The method of claim 14, wherein the support structure comprises a plurality of frame members located adjacent an edge of the film.

17. The method of claim 14, wherein the film is heated to a temperature and for a time sufficient to shrink the film such that the film has a tension of less than or equal to 1.5 lb. per linear inch.

18. The method of claim 14, comprising trimming the film prior to and after heat shrinkage.

19. The method of claim 14, wherein the film is secured to one of the support structure and the at least one edge spacer by at least one of a mechanical member, an adhesive, the primary sealant, or a thermoplastic welding process.

20. The method of claim 14, wherein the support structure comprises a plurality of frame members located adjacent an edge of the film, wherein the plurality of frame members are rigid solid or hollow profiles.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0020] The invention is illustrated in the accompanying drawing figures wherein like reference characters identify like parts throughout. Unless indicated to the contrary, the drawing figures are not to scale.

[0021] FIG. 1 is a cross-sectional side view of a multi-pane insulated glass unit in accordance with the prior art.

[0022] FIG. 2 is a cross-sectional side view of a multi-pane insulated glass unit in accordance with an embodiment of the invention.

[0023] FIG. 3 is an expanded side perspective view of a portion of the multi-pane insulated glass unit of FIG. 2 in accordance with an embodiment of the invention.

[0024] FIGS. 4A-4D are cross-sectional side views of a multi-pane insulated glass unit showing various arrangements for securing the third pane within the glass unit in accordance with invention.

[0025] FIGS. 5A-5D are cross-sectional partial views showing various arrangements for mounting the support structure in the multi-pane insulated glass unit.

[0026] FIG. 6A is a cross-sectional partial side view of frame/third pane in accordance with an embodiment of the invention.

[0027] FIG. 6B is a perspective view of the frame of FIG. 6A in accordance with an embodiment of the invention.

[0028] FIG. 7A is a cross-sectional partial side view of frame/third pane in accordance with an embodiment of the invention.

[0029] FIG. 7B is a perspective view of the frame of FIG. 7A in accordance with an embodiment of the invention.

[0030] FIG. 8A is a cross-sectional partial side view of frame/third pane in accordance with an embodiment of the invention.

[0031] FIG. 8B is a perspective view of the frame of FIG. 8A in accordance with an embodiment of the invention.

[0032] FIGS. 9A-9D show the steps of securing the third pane to the support structure in accordance with an embodiment of the invention.

[0033] FIGS. 10A and 10B show graphs illustrating the optimal temperature determination for a pre-attachment heating with film shrinking vs. use of a pre-shrunk or low-shrink film in accordance with the invention.

[0034] FIG. 11 is a graph showing an optical location for the center panel for the best thermal performance in accordance with a feature of the invention.

[0035] FIGS. 12A-12D are cross-sectional partial views showing various arrangements for pressure equalization between the panels of the multi-pane insulated glass unit in accordance with the invention.

[0036] FIG. 13A shows a perspective view of a multi-pane insulated glass unit including a muntin in accordance with an embodiment of the invention.

[0037] FIG. 13B shows a cross-sectional partial view of the multi-pane insulated glass unit of FIG. 13A in accordance with an embodiment of the invention.

DESCRIPTION OF THE INVENTION

[0038] Spatial or directional terms used herein, such as “left”, “right”, “upper”, “lower”, and the like, relate to the invention as it is shown in the drawing figures. It is to be understood that the invention can assume various alternative orientations and, accordingly, such terms are not to be considered as limiting.

[0039] As used herein, spatial or directional terms, such as “left”, “right”, “inner”, “outer”, “above”, “below”, and the like, relate to the invention as it is shown in the drawing figures. However, it is to be understood that the invention can assume various alternative orientations and, accordingly, such terms are not to be considered as limiting. Further, as used herein, all numbers expressing dimensions, physical characteristics, processing parameters, quantities of ingredients, reaction conditions, and the like, used in the specification and claims are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical values set forth in the following specification and claims may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical value should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Moreover, all ranges disclosed herein are to be understood to encompass the beginning and ending range values and any and all subranges subsumed therein. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less, e.g., 1 to 3.3, 4.7 to 7.5, 5.5 to 10, and the like. Additionally, all documents, such as, but not limited to, issued patents and patent applications, referred to herein are to be considered to be “incorporated by reference” in their entirety. Any reference to amounts, unless otherwise specified, is “by weight percent”. The term “film” refers to a transparent barrier layer, specifically, a thin plastic sheet such as PET.

[0040] The term “over” means “atop”. For example, a multiple pane IGU layer may be placed atop or over other layers or panes, where there may exist a space between the layer containing an air gap or air chamber.

[0041] The discussion of the invention herein may describe certain features as being “particularly” or “preferably” within certain limitations (e.g., “preferably”, “more preferably”, or “even more preferably”, within certain limitations). It is to be understood that the invention is not limited to these particular or preferred limitations but encompasses the entire scope of the disclosure.

[0042] As used herein, the transitional term “comprising” (and other comparable terms, e.g., “containing” and “including”) is “open-ended” and open to the inclusion of unspecified matter. Although described in terms of “comprising”, the terms “consisting essentially of” and “consisting of” are also within the scope of this disclosure.

[0043] The invention comprises, consists of, or consists essentially of, the following aspects of the invention, in any combination. Various aspects of the invention are illustrated in separate drawing figures. However, it is to be understood that this is simply for ease of illustration and discussion. In the practice of the invention, one or more aspects of the invention shown in one drawing figure can be combined with one or more aspects of the invention shown in one or more of the other drawing figures.

[0044] Reference is now made to FIG. 1, which shows a cross-sectional side view of a multi-pane insulated glass unit, generally indicated as 1, in accordance with the prior art. The unit 1 includes a pair of glass panes 2a, 2b in a parallel, spaced apart relation. A third pane, in form of a coated film 4, is positioned between the panes 2a, 2b, creating open spaces 5a, 5b between the panes 2a, 2b and the film 4. The film 4 is secured to edge spacers 8a, 8b with a primary sealant 6. The edge spacers 8a, 8b extend generally about the periphery of their respective pane 2a, 2b. The edge spacers 8a, 8b are of identical dimensions in cross-section so that the film 4 is positioned midway between the opposing panes 2a, 2b. The edge spacers 8a, 8b can be shaped such that when the panes 2a, 2b are attached to the edge spacers 8a, 8b, the panes 2a, 2b are parallel to each other and to the film 4. A secondary sealant 7 is provided to further secure the film 4 and within the unit 1. The process for making the glass unit 1 of the prior art includes the steps of assembling the entire unit, including the panes 2a, 2b, the film 4, the edge spacers 8a, 8b, the primary sealant 6, the secondary sealant 7; curing the sealants, which can take up to 2 hours; shrinking the film 4 in an oven, which can take an additional 2 more hours; then manually filling the spaces 5a, 5b with an inert gas, such as argon.

[0045] In the prior art design, the use of the edge spacers 8a, 8b sandwiching the center film 4, forms two interfaces with the primary sealant material 6, which is further extended outward to be gripped by the secondary sealant 7, which provides the mechanical support. This can result in the application of shear stress on the seal, which may raise the potential for seal failure. Also, these two additional interfaces result in additional failure points for air ingress which can degrade the thermal performance of the unit 1. Additionally, the time to construct the unit 1 can take several hours, anywhere from 3-5 hours, or more.

[0046] Reference is now made to FIGS. 2-3, which show the multi-pane insulated glass unit, generally indicated as 10, in accordance with an embodiment of the present invention. The unit 10 includes a pair of glass panes 12a, 12b in a parallel, spaced apart relation. At least one edge spacer 18 is provided between the glass panes 12a, 12b. A first or primary sealant 16 is located between adjacent edges of the pair of panes 12a, 12b to provide an integral sealed unit defining a space 15 therebetween. At least one transparent film 14 is located within the space 15 between the pair of glass panes 12a, 12b. The at least one transparent film 14 is secured to one of a support structure 20, as shown in FIGS. 2, 3, and 4A-4C, or the at least one edge spacer 18, as shown in FIG. 4D, such that the film is positioned in a spaced apart parallel relationship between the pair of glass panes 12, 12a, 12b to create a pair of spaces 15a, 15b. The spaces 15a, 15b can be filled with air or gas to reduce heat conductance across the window structure. Any inert, low heat transfer gas may be used, including krypton, argon, sulfur hexafluoride, carbon dioxide or the like. A combination and/or different gases can be used in the spaces 15a, 15b to obtain a desired reduction of heat conductance. This filling gas can contain some appreciable amount of oxygen to prevent or minimize yellowing of the interior film 14.

[0047] The film 14 is annealed prior to positioning of the film 14 between the pair of glass panes 12a, 12b. This annealing step releases the tension in the film 14 via stress induced crystallization.

[0048] This step typically takes a few minutes, depending upon the material used for the film 14 and the temperature at which the film 14 is heated for annealing the film 14.

[0049] Depending upon the type of film 14 being used, the film 14 is heated to a certain annealing temperature that is at least equal to the glass transition temperature of the film 14 so as to cause stress induced crystallization of the film 14. According to one embodiment, the film can be heated to an annealing temperature of at least 70° C. for approximately ten minutes. According to other embodiments, the film can be heated to above 110° C., 90° C., or 85° C.

[0050] According to the embodiment shown in FIGS. 2, 3, and 4A-4C, the at least one transparent film 14 is supported by the frame member 20. The film 14 can be secured to the support structure 20 wherein the support structure 20 comprises at least one frame member 20 located adjacent an edge and extending about the periphery of the film 14. This at least one frame member 20 can be a rigid frame made of a rigid solid or hollow profiles such as a rigid hollow aluminum profile with rectangle cross section (½″×¼″) and a wall thickness of 1/16″. According to another embodiment, the support 20 can comprise a pair of frame members 20a, 20b sandwiching an edge of the film 14 and extending about the periphery of the film 14.

[0051] In the FIG. 4A arrangement, a single edge spacer 18 is located between the panes 12, and a plurality of frame members 20, are provided to support the film 14. The edge spacer 18 can be a C-shaped member having a vertical side portion and horizontal top and bottom portions. The edge spacer 18 extends generally about the periphery of panes 12. The frame member 20 can be mechanically or adhesively secured to the interior of the edge spacer 18 or by any other well-known technique. See also FIG. 5A. The frame member 20 and film 14 can be located equidistantly between the panes 12, so as to create equal spaces 15a, 15b between the film 14 and the panes 12. Alternatively, the frame member 20 and film 14 can be located between the panes 12 such that one of the spaces 15a or 15b is larger than the other of spaces 15a, 15b. A primary sealant 16 can be used to secure the edge frame 18 to the panes 12 and can extend along the vertical side portion 28 of the edge spacer 18. An adhesive can be used to secure the film 14 to the frame members 20.

[0052] The FIG. 4B arrangement shows a frame member 20 in a floating arrangement with the edge spacer 18. In this arrangement, the film 14 is secured to a plurality of frames 20 and the frames 20 are mounted interior to the edge spacer 18 such that it is outside of the edge spacer 18 and interior to the vision area 13 of the unit 10. The frame members 20, can be secured therein with outer mechanical structures, such as welding or soldering, such that the frame is not structurally supported by the edge spacer 18. The edge spacer 18 can be shaped such that when the panes 12 are attached to the edge spacers 18, the panes 12 are parallel to each other and to the film 14. Primary sealant 16 can be positioned surrounding the edge member 18 and between the panes 12. An adhesive can be arranged on either side of the film 14 between the frame members 20 and the film 14 to allow for securing the film 14 to the frame members.

[0053] The FIG. 4C arrangement shows the floating arrangement of FIG. 4B which can be further secured to the edge spacer 18 with a pair of clips 46. In this arrangement, the frame members 20 holding the film 14 are dropped in the unit 10 such that it is outside of the edge spacer 18 and interior to the vision area 13 of the unit 10, and the pair of clips 46 allow the frame members 20 to snap-in to the edge spacer 18. The clips 46 attach to each frame member 20 to secure the middle portion of the unit 10.

[0054] According to the embodiment of FIG. 4D, the frame members 20a, 20b may be staggered in sizing. The unit 10 contains the same primary sealant 16 surrounding the edge spacer 18. Within the edge spacer 18 may be another series of clips 40 which attach only to the larger frame portion 20b. The film 14 is positioned above the larger frame 20b with an adhesive securing the film 14 to each side of the frames 20a, 20b. The smaller frame 20a may be positioned after the positioning of the larger frame 20b and film 14 so as to create a mechanical seal of the middle structure within the unit 10.

[0055] Reference is now made to FIGS. 5A-5D, which show various arrangements for securing the frame member 20 to the edge spacer 18. FIG. 5A illustrates an arrangement wherein the frame member 20 holding the film 14 is positioned interior and/or inside the edge spacer 18. FIG. 5B illustrates an arrangement wherein the frame member 20 holding the film 14 is dropped in the unit 10 such that it is outside of the edge spacer 18 and interior to the vision area 13 of the unit 10. FIG. 5C illustrates yet another arrangement wherein the frame member 20 holding the film 14 is located interior to vision area 13, but is snapped into edge spacer 18 with clips 46. FIG. 5D illustrates an arrangement wherein the frame members 20a, 20b are staggered in sizing, creating unequal spaces 15a, 15b in the unit 10, and the frame members 20 are positioned such that a mechanical seal holds it in place within the unit 10.

[0056] The film 14 can be annealed after being secured to the support structure 20. The film 14 is mechanically stretched to a tensioned state to remove wrinkles, after which time heat is applied to further shrink the film 14 wherein the film 14 has a tension of less than or equal to 1.5 lb. per linear inch.

[0057] The film 14 can be formed from at least one of a polymeric sheet, a thin glass sheet, and/or any other transparent sheet. The polymeric sheet can comprise a reinforced organic material. According to one embodiment, the film 14 can be a polymeric sheet comprising polyethylene terephthalate (PET). The PET film 14 can have a thickness 0.5-10 mil, 0.5-5 mil, or even 0.5-2 mil. At least one surface of the film 14 can include a low-e coating. It has been found that the insulated glass unit 10 of the present invention can achieve a much greater thermal performance than prior art arrangements by including low-e coatings on the glass panes 12a, 12b and/or the film 14 on one or more surfaces. In particular, it has been found that the unit 10 of the invention can have an R5 performance with lower cost Argon (Ar) and across a broader range of overall thickness and a R9 or better performance with Krypton (Kr) gas.

[0058] According to one embodiment, an adhesive 22 can be used to secure the film 14 to the frame member 20, or edge spacer 18, or other support structure. The adhesive 22 can be any known adhesive including a contact adhesive, a pressure sensitive adhesive, a UV curable adhesive, a thermally cured adhesive, or a chemically cured adhesive. According to yet another embodiment, the film 14 can be secured to the edge spacer 18 with the primary sealant 16. According to still another embodiment, the film can be heated to melt and bond with the frame member 20 or edge spacer 18 without the need for an adhesive or sealant.

[0059] According to one embodiment and with reference to FIGS. 6A, 6B, 7A, 7B, 8A, and 8B, the film 14 can be secured to the support structure 20 or the at least one edge spacer by the use of a mechanical member. The support structure 20 can include a pair of frame members 20a, 20b in which the film is sandwiched therebetween and wherein the frame members 20a, 20b are held together at the corners with keys or other mechanical fixtures or joining structures 50a, 50b such as a dove-tail, adhesive covering at least a portion of the side member, and a transparent panel adhered to the side-member by an adhesive. Another arrangement can include the frame members 20a, 20b having corners that are fabricated using a notch in the side and then folding of that side to form the corner, adhesive covering at least a portion of the side-member, and the transparent film 14 adhered to the side by an adhesive.

[0060] The film 14 can be attached to the pair of frame members 20a, 20b with mechanical clips or other fixtures. The mechanical securement of the film 14 can be achieved using key/lock profiled pair of frames as described below.

[0061] For example, as shown in FIGS. 6A and 6B, the key/lock members can be a plurality of cone-shaped discrete members 52a, 52b running along the edges of the frame members 20a, 20b, which are configured to mechanically mate with the film 14 located therebetween. FIGS. 7A and 7B show a series of key/lock rod-shaped rounded members 54a, 54b extending along the length of the edges of the frame members 20a, 20b. FIGS. 8A and 8B show a series of key/lock rod-shaped continuous cone members 56a, 56b extending along the length of the edges of the frame members 20a, 20b.

[0062] With continuing reference to FIGS. 2 and 3 and with further reference to FIGS. 9A-9D, the method for forming the insulating glass unit 10 comprises providing the pair of glass panes 12a, 12b in a parallel, spaced apart relation, providing at least one film 14, and pre-stretching the film, as shown in FIG. 9A, through the use of rollers 30, such as a bowed roll, vacuum roll, or nip roll type wrinkle removal systems 30 or any other anti-wrinkle system. This process typically takes less than 1 minute to complete. The next step in the process, as shown in FIG. 9B comprises securing the film 14 to either the support structure 20 or at least one edge spacer 18, and trimming the film 14 to size indicated by the arrow of FIG. 9B. This step requires a few seconds to complete. As shown in FIG. 9C, heat, as shown by arrows 34, is applied to shrink the film 14 to a tensioned state, as shown in FIG. 9D. The film 14 may then be trimmed or cut around the perimeter of the support structure 20 for an aesthetically pleasing look. The heat shrinkage step can be accomplished in less than one minute, depending upon the material used to form the film 14. After heat shrinkage, the film 14 is positioned between the pair of glass panes 12a, 12b such that the film 14, with or without a support structure 20, is positioned in a spaced apart parallel relationship between the pair of glass panes 12a, 12b. At least one edge spacer 18 and a primary sealant 16 is provided between adjacent edges of the pair of panes 12a, 12b, to provide an integral sealed unit 10 defining a space 15 therebetween. It can be appreciated that the steps 9A-9D can be performed on a machine with articulated motion whereby any or all of the steps can be done automatically.

[0063] According to one embodiment, the film 14 can be secured to the support structure 20 and the film 14 and support structure 20 are positioned between the pair of glass panes 12a, 12b at a location that is separate from the at least one edge spacer 18, such as at a location that is interior to the vision area 13 of the unit 10.

[0064] The support structure 20 can comprise at least one frame member 20a located adjacent an edge of the film 14 or a pair of frame members 20a, 20b sandwiching an edge of the film 14. According to one embodiment, the support structure 20 can comprise a plurality of frame members 20a, 20b located adjacent an edge of the film 14, wherein the plurality of frame members 20a, 20 b are rigid and can be made of rigid solid or hollow profiles such as a rigid hollow aluminum profile with rectangle cross section (½″×¼″) and a wall thickness of 1/16″. The frame members 20a, 20b can be formed using any known method including a molding process, stamping process, 3-D printing process, and the like.

[0065] The film 14 can be heated to a temperature and for a time sufficient for the film 14 to shrink and remove wrinkles, where the film then has a tension of less than or equal to 1.5 lb. per linear inch.

[0066] The method further comprises trimming the film 14 after it is shrunk to the rigid state and secured to one of the support structure 20 and the at least one edge spacer 18. The film 14 can be trimmed using a knife, blade, laser, and the like. The film 14 can be secured to one of the support structure 20 and the at least one edge spacer 18 by at least one of a mechanical member, an adhesive, or a thermoplastic welding process.

[0067] It can be appreciated that the film 14 can also include at least one of materials embedded therein or coated on one or both sides to control transmission and/or reflection spectra. A pattern can be printed on the film 14 either before or after the film 14 is affixed to the support structure 20 or the spacer 18. The film 14 can be coated with or have an aesthetic material applied to the portion visible to the end user allowing for additional designs which would be visually appealing to the end user. At least one surface of the film 14 can include a low-e coating. According to one embodiment, the optical haze of unit 10 can be less than 3% as measured by a BK Gardner Hazegard, and preferably less than 1.5%, and preferably less than 1%.

[0068] Also, the film 14 can be designed to have a thermochromic function for passive control of the optical (visible and/or the IR regions) transmission and/or reflection spectra, either with materials embedded into the film 14 or by applying a coating on one or both surfaces 14a, 14b, of the film 14.

[0069] Reference is made to FIG. 10A, which shows the optimal temperature determination for pre-attachment heating (i.e., film shrink) step. FIG. 10B shows the temperature determination using a pre-shrunk or low-shrink film wherein a heat stabilized film is not required. The heat profile (i.e., temperature vs. time) is such that the film is wrinkle free and the stress is such that essentially no force is applied to the frame member 20 of spacer 18.

[0070] Reference is made to FIG. 11, which shows a graph depicting an optical location for the film 14 for the best thermal performance of the unit 10. As shown in FIG. 11, the best location for the film 14 is on the centerline between the inner surfaces of the outer glass panes 12a, 12b. However, as shown in FIG. 11, the film 14 can also be positioned at an offset location from the centerline or of the space 15 between the inner surfaces of the outer glass panes 12a, 12b and still achieve improved thermal performance vs. a two panel insulated glazing unit.

[0071] With continuing reference to FIGS. 2-3 and 4A-4D and with further reference to FIGS. 12A-12D, the pair of glass panes 12 can comprise a first glass pane 12a and a second glass pane 12b. A first chamber 15a is located between the first glass pane 12a and a first side 14a of the film 14 and a second chamber 15b is located between the second glass pane 12b and a second side 14b of the film 14. An opening can be provided to allow for a gas to travel between the first chamber 15a and the second chamber 15b to ensure pressure equalization between the first chamber 15a and the second chamber 15b. In accordance with an embodiment shown in FIG. 12A, where the film 14 is integrated with spacers 18a and 18b, the opening 44a can be provided in the film 14. In the embodiment shown in FIG. 12B, where the film 14 is secured to a support structure 20 and the support structure 20 and film 14 are located interior to a vision area 13 of the unit 10, openings 44b can be provided in the support structure 20. In the embodiment shown in FIG. 12C, where the support structure 20 and the film 14 are located inside of the spacer 18, openings 44c, in the form of multiple openings, can be provided in the support structure 20. In the embodiment shown in FIG. 12D, the support structure 20 is secured interior to the vision area 13 of the unit 10 with clips 46 that cooperate with the spacer 18. In this embodiment, the opening 44d is provided in the support structure 20.

[0072] Reference is now made to FIGS. 13A, and 13B which show muntins 40. The muntins 40 can be attached to either the edge spacer 18 or the support structure 20, or both. The muntins 40 may be attached with or without clips. According to one arrangement, the muntins 40 can be inserted within a notch 42 within the upper frame 20a and the film 14 can be attached to the lower frame 20b. Alternatively, muntins 40 can be printed on the film.

[0073] The invention is further described in the following numbered clauses.

[0074] Clause 1: An insulating glass unit comprising: a pair of glass panes in a parallel, spaced apart relation; at least one edge spacer and at least a primary sealant located between adjacent edges of the pair of panes to provide an integral sealed unit defining a space therebetween; and at least one transparent film located within the space between the pair of glass panes, said at least one transparent film secured to one of a support structure and the at least one edge spacer, wherein the film is positioned in a spaced apart parallel relationship between the pair of glass panes, and wherein the film is tensioned prior to positioning of the film between the pair of glass panes.

[0075] Clause 2: The insulating glass unit of claim 1, wherein the at least one transparent film is supported by the support structure and the support structure is separate from the edge spacer.

[0076] Clause 3: The insulating glass unit of clause 2, wherein the support structure comprises a plurality of frame members located adjacent an edge of the film.

[0077] Clause 4: The insulating glass unit of clause 3, wherein the plurality of frame members each are rigid solid or hollow profiles such as a rectangle hollow aluminum profile with a wall thickness of 1/16″.

[0078] Clause 5: The insulating glass unit of any one of clauses 2-4, wherein the film is annealed prior to or after securing the film to the support structure.

[0079] Clause 6: The insulating glass unit of any one of clauses 1-5, wherein the tensioned state of the film has a tension of less than or equal to 1.5 lb. per linear inch.

[0080] Clause 7: The insulating glass unit of any one of clauses 1-6, wherein the film is heated to a temperature of at least 100° C. for less than or equal to one minute.

[0081] Clause 8: The insulating glass unit of any one of clauses 1-7, wherein the film comprises at least one of a polymeric sheet, a thin glass sheet, and any other transparent sheet.

[0082] Clause 9: The insulating glass unit of clause 8, wherein the film is a polymeric sheet comprising polyethylene terephthalate.

[0083] Clause 10: The insulating glass unit of any one of clauses 1-9, wherein the film is secured to the support structure or the at least one edge spacer by at least one of a mechanical member, an adhesive, the primary sealant, or by thermoplastic welding.

[0084] Clause 11: The insulating glass unit of clause 2, wherein the support structure is secured to the edge spacer.

[0085] Clause 12: The insulating glass unit of clause 2, wherein the pair of glass panes comprises a first glass pane and a second glass pane and wherein the support structure is configured to allow for a gas to travel between a first chamber located between the first glass pane and a first side of the film and a second chamber located between the second glass pane and a second side of the film to ensure pressure equalization between the first chamber and the second chamber.

[0086] Clause 13: The insulating glass unit of any one of clauses 1-12, wherein the film includes at least one of materials embedded therein or coated on one or both sides to control transmission and/or reflection spectra.

[0087] Clause 14: A method for forming an insulating glass unit comprising: providing a pair of glass panes in a parallel, spaced apart relation; providing at least one film; stretching the film to remove wrinkles; securing the film to one of a support structure; applying heat to shrink the film, wherein the step of heating the film occurs before or after the step of securing the film to one of the support structure and the at least one edge spacer; positioning the film secured to one of the support structure between the pair of glass panes such that the film is positioned in a spaced apart parallel relationship between the pair of glass panes; and providing the at least one edge spacer and a primary sealant between adjacent edges of the pair of panes to provide an integral sealed unit defining a space therebetween.

[0088] Clause 15: The method of clause 14, wherein the film is secured to the support structure and the film and support structure are positioned between the pair of glass panes at a location that is separate from the at least one edge spacer.

[0089] Clause 16: The method of clauses 14 or 15, wherein the support structure comprises a plurality of frame members located adjacent an edge of the film.

[0090] Clause 17: The method of any one of clauses 14-16, wherein the film is heated to a temperature and for a time sufficient to shrink the film such that the film has a tension of less than or equal to 1.5 lb. per linear inch.

[0091] Clause 18: The method of any one of clauses 14-17, comprising trimming the film prior to and after heat shrinkage.

[0092] Clause 19: The method of any one of clauses 14-18, wherein the film is secured to one of the support structure and the at least one edge spacer by at least one of a mechanical member, an adhesive, the primary sealant, or a thermoplastic welding process.

[0093] Clause 20: The method of any one of clauses 14-19, wherein the support structure comprises a plurality of frame members located adjacent an edge of the film, wherein the at least one frame member is rigid solid or hollow profile such as a hollow rectangle aluminum profile (½″×¼″) with a wall thickness of 1/16″.

[0094] While the disclosure has been described as having exemplary designs, the present disclosure can be further modified within the spirit and scope of this disclosure. This application is, therefore, intended to cover any variations, uses, or adaptations of the disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this disclosure pertains and which fall within the limits of the appended claims.