PACKAGED FILM ASSEMBLY FOR LAMINATION BETWEEN SUBSTRATES

A packaged film assembly includes a packaging material and an insert film. The insert film is packaged in and attached to at least a portion of the packaging material. The packaging material is not laminated to another surface.

TECHNICAL FIELD

The present disclosure is directed at a packaged film assembly for lamination between substrates.

BACKGROUND

Conventional laminated glass comprises two glass panels between which is laminated a sheet of polyvinyl butyral (“PVB”). The PVB is laminated to the glass panels under a combination of heat and pressure and, once laminated, bonds the panels together. The PVB also acts as a protective and flexible interlayer to which glass fragments adhere should either of the panels fracture. Laminated glass is consequently commonly used in applications where safety is paramount, such as automobile windshield manufacturing.

In certain applications, laminated glass may comprise more than one interlayer. For example,FIG. 1shows an exploded view of a prior art window assembly A prior to lamination. The assembly A comprises top and bottom glass panels B between which are three interlayers. Top and bottom PVB sheets C are the interlayers nearest the top and bottom panels B, respectively. Between the PVB sheets C are a PVB frame F and a switchable film D from which extend electrical leads E to which an electrical signal is applied to cause the switchable film D to transition from a dark state of relatively low optical transmittance to a light state of relative high optical transmittance, or vice-versa; the switchable film D comprises, for example, polyethylene terephthalate (“PET”). The PVB frame F circumscribes the switchable film D. Compared to laminating a single PVB sheet between two glass panels, manufacturing the assembly A ofFIG. 1requires cutting multiple sheets of interlayer and carefully aligning the frame F and switchable film D relative to each other and the rest of the assembly A.

Additionally, part of preparing the assembly A for lamination comprises eliminating the air bubbles between the glass panels B. Air that is trapped between the panels B during lamination can lead to one or both of optical and mechanical defects in the laminated window assembly A. Several involved techniques exist in the art for removing air bubbles as part of the overall lamination process; these include performing nip roll lamination or using a vacuum ring/bag.

Preparing and laminating the window assembly A is accordingly a time intensive process that is difficult to automate and that typically requires employing significant professional skill to perform successfully.

SUMMARY

According to a first aspect, there is provided a packaged film assembly. The packaged film assembly comprises a packaging material; and an insert film packaged in and attached to at least a portion of the packaging material, wherein the packaging material is not laminated to another surface.

According to another aspect, there is provided a packaged film assembly that comprises a packaging material comprising a first film laminable to a first substrate and a second film laminable to a second substrate, wherein each of the first and second films is translucent; and an insert film located between the first and second films, wherein the first film directly contacts a first side of the insert film and a second film directly contacts a second side of the insert film that is opposite to the first side. One or both of the first and second films may comprise polyvinyl butyral (“PVB”).

According to another aspect, there is provided a packaged film assembly that comprises a packaging material comprising a first film laminable to a first substrate and a second film laminable to a second substrate; and an insert film located between the first and second films, wherein the first film directly contacts a first side of the insert film and a second film directly contacts a second side of the insert film that is opposite to the first side. The first film comprises a rough outwardly facing surface that is opposite a surface of the first film that contacts the insert film, and the second film comprises a rough outwardly facing surface that is opposite a surface of the second film that contacts the insert film. One or both of the first and second films may comprise PVB.

The following are features that may be applied to any of the foregoing aspects of the packaged film assembly.

The packaging material may comprise PVB or ethylene-vinyl acetetate (“EVA”).

The insert film may be a switchable film configured to switch between a dark state and a light state.

The switchable film may transition from the light state to the dark state upon exposure to sunlight and from the dark state to the light state when a voltage is applied across the switchable film absent exposure of the switchable film to sunlight.

The switchable film may comprise polyethylene terephthalate (“PET”).

The packaging material may comprise a first and a second interlayer, wherein the first interlayer comprises a first film laminable to a first substrate and in direct contact with a first side of the insert film and wherein the second interlayer comprises a second film laminable to a second substrate and in direct contact with a second side of the insert film that is opposite to the first side.

The first and second films may overlap and be secured to each other at one or more overlapping portions around the insert film.

The one or more overlapping portions may comprise a single overlapping portion that circumscribes at least part of the insert film.

The single overlapping portion may circumscribe the entirety of the insert film.

The assembly may further comprise a bonding material in the overlapping portion that bonds the first and second films to each other.

The one or more overlapping portions may comprise discrete regions located around the insert film.

The discrete regions may delimit a pouch that contains the insert film.

The first film may be bonded directly to the first side of the insert film and the second film may be bonded directly to the second side of the insert film.

The first and second films may be bonded to the insert film along a periphery of the insert film to form an edge seal.

The insert film may comprise a pair of PET coverlays located between the first and second films, wherein one of the PET coverlays is secured to the first film and the other of the PET coverlays is secured to the second film; a pair of electrically conductive electrodes located between the PET coverlays, wherein one of the electrodes is secured to one of the PET coverlays and the other of the electrodes is secured to the other of the PET coverlays, and wherein each of the electrodes comprises an overhanging portion that extends past an edge of the other of the electrodes; a pair of bus bars, wherein one of the bus bars is electrically coupled to the overhanging portion of one of the electrodes and the other of the bus bars is electrically coupled to the overhanging portion of the other of the electrodes; a switching material located between the electrodes; and an epoxy between and bonding the PET coverlays to each other.

The packaging material may comprise a frame that extends around at least a portion of the insert film.

The packaging material may circumscribe the entirety of the insert film.

The frame may comprise de-airing channels extending from an interior edge to an exterior edge of the frame.

The frame may comprise tabs extending towards the insert film, and the insert film may be attached to the tabs.

The packaging material may further comprise a first film laminable to a first substrate and in direct contact with a first side of the frame and a second film laminable to a second substrate and in direct contact with a second side of the frame that is opposite to the first side.

The assembly may further comprise a pair of bus bars located between the first and second films, wherein one of the bus bars is attached to the first film and the other of the bus bars is attached to the second film; a pair of PET substrates located between the first and second films, wherein one of the PET substrates is secured to the first film and the other of the PET substrates is secured to the second film, and wherein each of the PET substrates comprises an overhanging portion that extends past an edge of the other of the PET substrates; a pair of electrical coatings located between the PET substrates, wherein one of the electrical coatings is on one of the PET substrates and the other of the electrical coatings is on the other of the PET substrates; and a switching material located between the electrical coatings.

According to another aspect, there is provided a method for manufacturing a packaged film assembly. The method comprises forming a packaging material; forming an insert film; and packaging the insert film in the packaging material, wherein the packaging material is not laminated to another surface and wherein packaging the insert film comprises attaching the insert film to at least a portion of the packaging material.

Forming the packaging material may comprise forming a frame; and forming first and second sheets manufactured from a laminable material, and the method may further comprise laying the first sheet on a flat surface; aligning the frame on the first sheet; aligning the insert film within the frame; aligning the second sheet on the frame and the insert film; and attaching each of the first and second sheets to opposing sides of the frame.

DETAILED DESCRIPTION

Laminating a single interlayer such as PVB between two glass panels is a relatively straightforward process. Only a single sheet of the interlayer needs to be cut to size, and a laminator can eliminate any air bubbles that may exist between the interlayer and the glass panels relatively efficiently and reliably. However, laminating multiple interlayers between glass panels is significantly more challenging. Conventionally, the laminator needs to cut and align multiple sheets of interlayer. Furthermore, removing air bubbles is more difficult for the laminator when multiple interlayer sheets are used than when only a single sheet of interlayer is used.

The embodiments described herein are directed at a packaged film assembly that allows a laminator to approach multiple interlayer lamination in a manner more similar to single interlayer lamination than is possible using conventional lamination methods. An insert film that comprises, for example, PET, is packaged using a packaging material such as PVB, ethylene-vinyl acetate (“EVA”), thermoplastic polyurethane (“TPU”), or thermoplastic olefin (“TPO”). In some embodiments, the packaging material comprises sheets of laminating film between which the insert film is placed, and “packaged” refers to encapsulation of the insert film by the sheets of laminating film; i.e., the sheets of laminating film cover the edges and both sides of the insert film except for, in certain embodiments, electrical leads (see, e.g., the embodiment ofFIG. 11). In some other embodiments in which the insert film is positioned between sheets of laminating film that act as the packaging material, “packaged” refers to coverage of both sides, but not the edges, of the insert film by the sheets of laminating film (see, e.g., the embodiment ofFIG. 4). In still other embodiments, “packaged” refers to using the packaging material to form a frame that circumscribes the periphery of the insert film (see, e.g., the embodiment ofFIG. 9). In the depicted embodiments, the insert film is attached, directly or indirectly, to at least a portion of the packaging material.

The packaged film assembly is then delivered to a laminator who may proceed to laminate it between two substrates without having to cut multiple sheets of interlayer and without having to align the insert film and interlayers in the manner required during conventional multilayer lamination. Using the packaged film assembly as described herein accordingly simplifies the lamination process for the laminator, facilitating increased productivity. Examples of the substrates to which the interlayer and insert film are laminated include glass and polymer (e.g., polycarbonate), and in certain embodiments one of the substrates may be manufactured using one type of material and the other of the substrates may be manufactured using a different type of material. In one example embodiment, one or both of the substrates comprise a glass-plastics pane, which is a pane of laminated glass comprising one layer of glass and one or more layers of plastics material of which at least one acts as an interlayer.

While in the depicted embodiments the insert film comprises PET, in different embodiments (not depicted) the insert film may additionally or alternatively comprise one or more different thermoplastic polymers. For example, the insert film may additionally or alternatively comprise any one or more of polyethene (“PE”), polypropylene (“PP”), polybutylene terephthalate (“PBT”), polyethylene napththalate (“PEN”), polycarbonate (“PC”), and other engineering thermoplastics.

In the depicted embodiments, the insert film is a switchable film that is non-opaque in both the dark and light states; however, in non-depicted embodiments the insert film may comprise a non-switchable film that is non-opaque or opaque, or it may comprise a switchable film that is non-opaque in one of the states (e.g., comprise switchable film comprising a liquid crystal that is non-opaque only in the light state). The switchable film may be fabricated using photochromic, thermochromic, photochromic/electrochromic, liquid crystal, or suspended particle technologies. Photochromic optical filters tend to automatically darken when exposed to sunlight, and lighten in the absence of sunlight. Electrochromic, liquid crystal, and suspended particle technologies however, tend to alternate between dark and light operating states (or transmissive states) in response to electricity. Thermochromic optical filters darken or lighten when exposed to a change of temperature. Electrochromic optical filters, for example, tend to darken when a voltage differential is applied across a pair of terminals electrically coupled to different sides of the electrochromic material, and tend to lighten when the polarity of the voltage differential is reversed.

In the embodiments depicted herein, the switchable film is based on a hybrid photochromic/electrochromic technology, which darkens in response to sunlight, UV, or other particular wavelengths of electromagnetic radiation (hereinafter “light”) and lightens or becomes transparent (hereinafter “lighten”) in response to a non-zero voltage (hereinafter “voltage”) applied across the electrical leads connected to the switchable film. The switchable film comprises a switching material having one or more chromophores that are reversibly convertible between colored (dark) and uncolored (light) states; the switching material may further comprise a solvent portion, polymer(s) (such as PET), salts, or other components to support the conversion of the chromophore between colored and uncolored states when exposed to light or voltage. Some examples of chromophores include fulgides, diarylethenes or dithienylcyclopentenes. However, in different embodiments (not depicted), other types of optical filters comprising alternate switching materials with similar behavior to hybrid photochromic/electrochromic switching materials, may also be employed. Examples of various optical filters and their underlying chemistries may be found in U.S. Pat. No. 8,441,707, the entirety of which is hereby incorporated by reference.

Referring now toFIG. 2, there is shown a packaged film assembly100, according to one embodiment. The assembly100comprises a first film106comprising a PVB film that is 0.76 mm or 0.38 mm thick. A switchable film102is laid down on to the first film106so that the switchable film102is spaced from all the edges of the first film106; that is, the first film106circumscribes the border of the switchable film102when looking down at the switchable film102laid on the first film106. In one example embodiment, the switchable film102is 0.46 mm thick; additionally or alternatively, in certain embodiments the border formed by the first film106around the switchable film102is anywhere from a few millimeters to several centimeters or tens of centimeters wide. The switchable film102comprises two PET layers and a switching material between the two PET layers; each of the PET layers is coated with a conductive coating, and the PET layers are electrically connected to at least a pair of electrical leads104.

A second film108is then formed over the top of the first film106and switchable film102by casting a solution over the first and switchable films106,102that is allowed to dry. The solution is formed by dissolving a sheet of PVB that is suitable for use as an interlayer or by dissolving a resin formulation comprising, for example, PVB resin compound made up of PVB resin, a high boiling point plasticizer, and other additives such as UV absorbers or antioxidants, in a suitable low boiling point solvent that is a non-solvent for the PET comprising the switchable film102; here, being a “non-solvent” for PET means that the solvent does not swell PET. A suitable solvent is, for example an alcohol such as IPA (isopropanol), hydrocarbon such as tolulene, ether such as THF (tetrahydrafuran), or mixture of solvents. As shown inFIG. 2, once dry the switchable film102is encapsulated by the first and second films106,108, with only the electrical leads104extending beyond the edges of the films106,108.

As inFIG. 2, the embodiments depicted inFIGS. 3 to 13the switchable film102comprises PET and each of the first and second films106,108comprises PVB. However, as described above, in different embodiments (not depicted) the films102,106,108may have different compositions. In certain embodiments, the films106,108and, in particular, PVB are translucent prior to lamination, at which time they become transparent.

Referring now toFIG. 3, there is shown another example embodiment of the encapsulated switchable film assembly100. Similar to the embodiment ofFIG. 2, the first film106is laid on a surface, the switchable film102and electrical leads104are laid on the first film106, and the second film108is then laid on the switchable film102and first film106. The switchable film102is positioned relative to the first and second films106,108such that it is spaced from all the edges of those films106,108; this permits the peripheries of the first and second films106,108to directly contact each other, except where prevented by the electrical leads104.

After laying the films106,102,108, they are secured or attached together to facilitate shipping of the assembly100to a laminator. For example, the films106,102,108may be secured or attached to each other using an adhesive (e.g., one or both of pressure sensitive and low-tack adhesive, tape, and spray adhesive). Additionally or alternatively, localized heat may be applied to overlapping portions of the films106,108to cause them to flow and bond together at those overlapping portions; the localized heat in the depicted embodiments exceeds PVB's glass transition temperature, but is below PVB's melting temperature. For example, the localized heat may be applied continuously along the films106,108such that the switchable film102is circumscribed by a loop of bonded PVB; alternatively, the localized heat may be applied at discrete regions of overlapping portions of the films106,108such that the films106,108are adhered to each other at discrete regions of bonded PVB; using heat in this manner to secure or attach the films106,108together is referred to as “tacking” in this disclosure. Additionally or alternatively, the films106,102,108may be compressed using a press (e.g., rollers), as discussed in more detail in respect ofFIG. 14below. When the press is used, release liners or materials that help to ensure that the first and second films106,108do not adhere to the surface of the press are used as appropriate. Additionally or alternatively, the films106,102,108may comprise mechanical interlocking features that permit the first and second films106,108to directly interlock with each other, or that permit each of the first and second films106,108to directly interlock with the switchable film102.

In certain embodiments, the laminated films formed using the packaged film assembly100may be designed and tested to pass various tests for laminated glass such as ANSI Z26.1-1996, ANSI Z26.1-2006, and ECE R43.

InFIG. 3, each of the films106,108is identical and has a thickness of 0.38 mm, although in different embodiments (not depicted) the films106,108may differ in one or more dimensions from each other and be of different thicknesses. Similarly, inFIG. 3the switchable film102has a thickness of approximately 0.25 mm, although in different embodiments (not depicted) it may have a different thickness.

FIG. 4shows an embodiment of the packaged film assembly100in which the switchable film102is packaged between the first and second films106,108, and in which the first and second films106,108have the same or slightly larger width and height than the switchable film102. For example, in one embodiment each of the first and second films106,108has a width and height that is approximately 1 cm greater than the width and height of the switchable film102, respectively; in different embodiments, one or both of the first and second films106,108may have a width and/or height that is approximately 0.1 cm, 0.2 cm, 0.3 cm, 0.4 cm, 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, or 0.9 cm greater than the width and/or height of the switchable film102. A moisture barrier or seal may be located in the edge region between the first and second films106,108through which the switchable film102does not extend. InFIG. 4, a zone of relatively high adhesion (“high adhesion zone”)402is along the periphery of the switchable film102to edge seal the assembly100. An epoxy, for example, may be used as an adhesive to create the high adhesion zone within the switchable film102. The switchable film102is then secured or attached to the first and second films106,108such that the position of the switchable film102is stable relative to the first and second films106,108. In certain embodiments this is achieved using an additional or temporary adhesive layer. Additionally or alternatively, tacking may be used to secure or attach the films102,106,108together. The assembly100is subsequently laminated and may then be sent to laminators for further lamination between glass using conventional single interlayer lamination techniques, as is done with the embodiment ofFIG. 3.

Referring now toFIG. 5, there is shown another embodiment of the packaged film assembly100. InFIG. 5, the switchable film102is again located between the first and second films106,108. The switchable film102comprises a pair of PET coverlays506that each has approximately the same width and height than the films106,108. The films106,108are tacked or otherwise secured or attached to the coverlays506. In a different embodiment, one or both of the coverlays506has a slightly smaller width and/or height (e.g., approximately 1 cm smaller in one or both of width and height) than the films106,108.

A pair of transparent, conductive electrodes in the form of indium tin oxide (“ITO”)-coated PETs502are adhered to the PET coverlays506using pressure sensitive adhesive502. Each of the ITO-coated PETs502is adhered to one of the coverlays506. The ITO-coated PETs502are positioned to face and to substantially overlap each other, with a portion of each of the ITO-coated PETs502extending past the edge of the other. The PET coverlays506have a greater surface area than the ITO-coated PETs502, and each of the ITO-coated PETs502is positioned on the PET coverlays506such that it is spaced from all the edges of the PET coverlay506to which it is adhered. A bus bar512is secured to the overhanging portion of each of the ITO-coated PETs502and a switching material510is located between the overlapping portions of the ITO-coated PETs502. An epoxy508fills the space between the PET coverlays506that is not occupied by the switching material510, ITO-coated PETs502, bus bars512, and pressure sensitive adhesive502. The epoxy508has good adhesion to the PET coverlays506and consequently provides a high adhesion zone402that helps to hold the assembly100together and acts as an edge seal.

The first and second films106,108may be tacked or otherwise bonded as described above in respect ofFIG. 3to the switchable film102after the switchable film102has been entirely assembled.

Referring now toFIG. 6, there is shown another example embodiment of the assembly100. In the embodiment ofFIG. 6, the first and second films106,108have approximately the same dimensions as, or slightly larger dimensions than, the switchable film102, which is located between the films106,108. The films106,108are sandwiched between two glass panes602, with the second film108spaced from all the edges of the upper glass pane602inFIG. 6and the first film108spaced from all the edges of the lower glass pane602inFIG. 6. A bonding material604that is approximately the same thickness as the combined thicknesses of the films102,106,108is also sandwiched between the glass panes602and circumscribes the films102,106,108, which comprises the area to be laminated. The bonding material604may be any suitable material such as PVB or PVS101made by Royal Adhesives and Sealants™ of Michigan Centre, Mich. Certain bonding materials such as PVS101may also act as good sealants against oxygen and moisture.

In contrast to the embodiments above, the bonding material604bonds directly to the glass panes602as opposed to the films106,108bonding only each other or the switchable film102, as inFIGS. 4 and 5. The assembly100that is shipped to the laminator may comprise the bonding material604and the films106,102,108, with the bonding material604and films106,102,108being secured or attached together using tape.

FIG. 7shows an embodiment of the encapsulated switchable film assembly100in which the first film106is manufactured by extruding PVB in a film that comprises a groove702shaped to receive the switchable film102. After the first film106sufficiently cools, the switchable film102is placed in the groove702and extruded strips of PVB are placed to abut against the ends of the groove702so that the switchable film102is framed on all edges by PVB. The second film108is placed over the first and switchable films106,102and the PVB portions that abut against the groove's702ends. The first and second films106,108and those PVB portions are then tacked together and sent to a laminator for lamination between glass. By virtue of being extruded, the groove702is shaped as a channel and has straight edges; consequently, for a close fit between the switchable film102and the edges of the groove702, the switchable film102in the depicted embodiment has straight edges as well. In different embodiments, the switchable film102may be differently shaped. Surface roughness can be imparted on the surface of one or both of the films106,108either as part of the extrusion process or after the extrusion process. The surface roughness may help with de-airing during subsequent lamination. In at least some example embodiments, surface roughness may be 15-25 μm (600-1,000 pinches), random in terms of amplitude variability and/or spatial frequency, or both.

FIGS. 8A and 8Bdepict frames802that may be used in various embodiments of the packaged film assembly100.FIG. 8Adepicts an example frame802that comprises a PVB film in which are cut apertures804. Each of the apertures804is shaped to receive one switchable film102, and extending perpendicularly from the edges of each of the apertures804towards the edges of the frame802are de-airing channels806that may assist with de-airing during lamination. The frame802shown inFIG. 8Amay be laminated to multiple panes of glass; for example, the frame802may be cut to separate the apertures804and each of the apertures804may be used in a packaged film assembly100that is used in a sunroof.

To manufacture the packaged switchable film assembly100using the frame802, the first film106is first laid on a surface and the frame802is laid on the first film106;FIG. 8Bis a sectional view of the frame802looking lengthwise along the apertures804when laid on the first film106. One of the switchable films102(not depicted inFIG. 8B) is put in each of the apertures804that is backed by the first film106, and the second film108(not depicted inFIG. 8B) is then laid over the frame802. The second film108may be secured or attached to the frame802(e.g., using an adhesive or localized heat, as described above forFIG. 3) to form the assembly100. In different embodiments (not depicted), the first and second films106,108may be directly bonded to each other around the frame802.

Referring now toFIG. 9, there is shown another embodiment of the packaged film assembly100comprising the frame802and the switchable film102. InFIG. 9, the aperture804in the frame802comprises four inwardly extending tabs902that attach to the switchable film102located within the aperture804. As discussed above in respect ofFIG. 3, the tabs902may be secured or attached to the switchable film102using any suitable means such as adhesive, tape, localized heat to form a tack weld, a mechanical rivet, and mechanical interlocking features in the film102and frame802.FIG. 9also shows the electrical leads104connected to the switchable film102and extending past the periphery of the frame802. Following manufacture, the assembly100is sent to a laminator who cuts the first and second films106,108, places the assembly100between them, and laminates the films106,108and assembly100to glass.

In the depicted embodiments of the assembly100comprising the frame802, the frame802and the first and second films106,108all comprise PVB. However, in different embodiments, the frame802and films106,108may have different compositions; for example, the frame may comprise a material that does not laminate (e.g., PET or a rigid substrate), or may comprise a material that does laminate but that nonetheless differs in composition from the films106,108. Additionally, while in the depicted embodiments the frame802and the switchable film102are approximately the same thickness, in different embodiments, such as those in which the frame802is manufactured using a compliant material such as PVB, they may have different thicknesses. In the depicted embodiments in which the switchable film102comprises PET and the frame802comprises PVB, the film102may be18mil thick and the frame802may be15mil thick. Additionally, while the frame802is shown inFIG. 9as circumscribing the entire switchable film102, in different embodiments the entire switchable film102need not be circumscribed. For example, as shown inFIG. 8A, portions of the frame802may comprise the de-airing channels806. In different, non-depicted embodiments, a greater proportion of the switchable film102may not be circumscribed by the frame802.

FIG. 10depicts an example method for manufacturing the packaged film assembly100. Molten or softened PVB is stored in a PVB reservoir1002that is pushed through the lips of an extrusion die1004simultaneously with the switchable film102. PVB films accordingly are deposited on the bottom and top of the switchable film102, which once dry are the first and second films106,108. Surface roughness can be imparted to the surface of substrates108and106either during the extrusion process or afterwards in order to help with de-airing during the lamination process. In at least some example embodiments, surface roughness may be 15-25 μm (600-1,000 μinches), random in terms of amplitude variability and/or spatial frequency, or both. The electrical leads104extend from a rear end of the switchable film102that is not pushed through the die1004to protect the leads104from being damaged. In some embodiments, the switchable film102is selected to have dimensions such that the extruded PVB covers its edges, thereby entirely encapsulating it. In different embodiments in which the switchable film102is not entirely encapsulated, one or both of the film's width and height are long enough so at least one edge of the film102is not encapsulated by the PVB. In these embodiments, the film102may extend to the edge of the PVB (e.g.,FIG. 4); additionally or alternatively, an additional material such as the bonding material604ofFIG. 6may be used to frame the film102.

FIG. 11depicts another embodiment of the packaged film assembly100comprising a pouch1102comprising the first and second films106,108having dimensions appropriate for the substrates to which they will eventually be laminated. InFIG. 11, the pouch1102comprises PVB and is formed by overlaying the first and second films106,108and then attaching three of the edges of the first and second films106,108together to form an attached PVB portion1104. One edge of the pouch1102comprises a sealable pouch opening1106that is initially left open. The switchable film102and electrical leads104are inserted into the pouch1102through the opening1106, following which the opening is closed similar to how the attached PVB portion1104is closed while still permitting the electrical leads104to protrude therefrom. InFIG. 11, the position of the switchable film102and electrical leads104after they are secured in the pouch1102is shown in dashed lines and labeled as102′ and104′, respectively. The pouch1102once assembled may then be placed between glass and laminated by a laminator using conventional lamination procedures. The switchable film102is secured or attached to the first and second films106,108once contained within the pouch1102notwithstanding that the switchable film102may be movable within the pouch1102.

In one different embodiment (not depicted), the sealable pouch opening1106is not closed but instead is left unsealed; in this embodiment, friction retains the switchable film102within the pouch1102.

Additionally, while inFIG. 11the first and second films106,108are fused together to form the fused PVB portion1104and consequently form the pouch1102, in a different embodiment (not depicted) an extra layer of PVB may be used to seal the periphery of the first and second films106,108to form the fused PVB portion1104.

FIG. 12depicts another embodiment of the packaged film assembly100in which the bus bars512are embedded directly into the PVB that comprises the first and second films106,108. The assembly100ofFIG. 12comprises the PVB frame802located between and along the periphery of the first and second films106,108. Two PET substrates1202with an electrically conductive coating1204act as electrodes and are positioned in the aperture804that the frame802defines and face and substantially overlap each other, and a portion of each of the PET coverlays506extends past the edge of the other. The switching material510is located between the overlapping portions of the PET substrates1202. When assembled, one of the PET substrates1202is secured or attached to the first film106and the other of the substrates1202is secured or attached to the second film108. One bus bar512is embedded into the second film108such that it contacts the electrically conductive coating1204of the PET substrate1202secured or attached to the first film106and another bus bar512is embedded into the first film106such that it contacts the electrically conductive coating1204of the PET substrate1202secured or attached to the second film108.

During lamination, the bus bars512bond to the conductive coatings1204on the PET coverlays506with which they are in contact, thereby forming the electrical connections to the switchable film102. Manufacturing the assembly100in this manner may simplify the forming of the switchable film102.

Other features and components may also be incorporated into the first and second films106,108. For example, one or both of the films106,108may contain colored pigments or dyes to form a colored filter that facilitates different colors or transmittance levels once the assembly100is laminated to glass. Additionally or alternatively, one or both of the films106,108may comprise ultraviolet light blocking features that block ultraviolet light, which can help to extend the lifetime of the switchable film102. Additionally or alternatively, pigments or dyes may be incorporated into one or both of the PET or other thermoplastic that comprises the switchable film102, and into the substrates to which the assembly100is laminated.

FIG. 14depicts an example embodiment of the packaged film assembly100being manufactured using calendaring and, more particularly, using two calendaring rollers1402. The calendaring rollers1402may be heated in order to help flow the PVB comprising the first and second films106,108and form it to the desired thickness. The switchable film102between the first and second films106,108are fed through the calendaring rollers1402. The gap labeled “x” inFIG. 14between the rollers1402is set at the final thickness desired for the packaged film assembly100. The calendaring rollers1402squeeze the PVB from an initial thickness labeled “y” inFIG. 14. The switchable film102is only minimally compressed by the calendaring process. In one example embodiment, the PVB is fed through the calendaring rollers1402in advance of the switchable film102so that the switchable film102may be encapsulated by fusing the PVB together in front of it. In this example embodiment the final thickness “x” is set less than “y/2” so the PVB is forced together even without the switchable film102. At the point at which the switchable film102starts going through the calendering rollers1402, the PVB is pressed even thinner by the rollers1402. In certain embodiments heat may be used to help with forming the PVB and to fuse it together on the leading edge. At the tailing edge and along the sides (not shown) of the first and second films106,108, the PVB in certain embodiments also overhangs the switchable film102so the first and second films106,108fully encapsulate the switchable film102. In the depicted embodiment, the electrical leads104are shown exiting from the back of the assembly100, but in non-depicted embodiments they may also exit from the side or from the front of the assembly100. The outer, curved surfaces of the calendering rollers1402may be textured so they impart surface roughness to exterior surfaces of the first and second films106,108; this texture may help with the de-airing process during any subsequent lamination. In at least some example embodiments, surface roughness may be 15-25 μm (600-1,000 pinches), random in terms of amplitude variability and/or spatial frequency, or both. The calendaring process can be done on a part-by-part batch process, or in a continuous process with many parts running through one after another. In certain embodiments, the rollers1402may be sufficiently heated such that the assembly100has sufficient structural integrity by virtue of heating and pressure alone; in different embodiments, other mechanisms such as an adhesive may additionally or alternatively be used to maintain the integrity of the assembly100. Additionally, in certain non-depicted embodiments, one or more additional rollers may be positioned to impart surface texture to one or both of the films106,108once they exit the rollers1402.

Referring now toFIG. 13, there is shown an example method1300for manufacturing the packaged film assembly100, according to another embodiment. The method1300begins at block1302where the switchable film102is formed by cutting it to size, sealing it, and attaching the electrical leads104to it. The frame802is formed at block1304as described, for example, in respect ofFIG. 8. At block1306the first and second sheets104,106are formed and at block1308the frame802is aligned relative to the first sheet104, which in this embodiment is laid on a surface first and is consequently the bottom sheet. At block1310the switchable film102is aligned within the frame802, and at block1312the second film108is laid on the frame802and switchable film102. At block1314the first and second films106,108are tacked or otherwise attached together as described, for example, inFIG. 12, to complete manufacture of the packaged film assembly100. A laminator may subsequently laminate the assembly100to appropriate substrates, such as glass panes for a window.

FIG. 13is a flowchart of an example embodiment of a method. Some of the blocks illustrated in the flowchart may be performed in an order other than that which is described. Also, it should be appreciated that not all of the blocks described in the flowchart are required to be performed, that additional blocks may be added, and that some of the illustrated blocks may be substituted with other blocks.

The switchable film102in the depicted embodiments does not melt or flow at the temperatures used to laminate the first and second films106,108. Similarly, in embodiments that comprise the PET coverlays506or PET substrates1202, neither the coverlays506nor the substrates1202melt or flow at the temperatures used to laminate the first and second films106,108. While in the depicted embodiments the switchable film102, PET coverlays506, and PET substrates1202all comprise PET and the films106,108comprise PVB, in certain other embodiments in which the films102,106,108, coverlays506, and substrates1202comprise different materials, the switchable film102, coverlays, and substrates also do not melt or flow at the temperatures required to laminate the first and second films106,108. For example, the melting temperatures of the materials comprising the switchable film102, coverlays, and substrates may be higher than the temperature used for lamination. The glass transition temperatures of the materials can be lower or higher than the temperature used for laminating. In embodiments in which the first and second films106,108comprise PVB, the lamination temperature is typically between approximately 125° C. and 140° C.

As used herein, the terms “approximately” and “about” when used in conjunction with a value mean +/−10% of that value.

Directional terms such as “top”, “bottom”, “upwards”, “downwards”, “vertically”, and “laterally” are used in this disclosure for the purpose of providing relative reference only, and are not intended to suggest any limitations on how any article is to be positioned during use, or to be mounted in an assembly or relative to an environment. Additionally, the term “couple” and variants of it such as “coupled”, “couples”, and “coupling” as used in this disclosure are intended to include indirect and direct connections unless otherwise indicated. For example, if a first article is coupled to a second article, that coupling may be through a direct connection or through an indirect connection via another article. Furthermore, the singular forms “a”, “an”, and “the” as used in this disclosure are intended to include the plural forms as well, unless the context clearly indicates otherwise. Additionally, the term “and/or” when used in conjunction with a list of items means any one or more of the items of that list.

It is contemplated that any part of any aspect or embodiment discussed in this specification can be implemented or combined with any part of any other aspect or embodiment discussed in this specification.

While particular embodiments have been described in the foregoing, it is to be understood that other embodiments are possible and are intended to be included herein. It will be clear to any person skilled in the art that modifications of and adjustments to the foregoing embodiments, not shown, are possible.