WO2019008496A1

WO2019008496A1 - Method for bending and laminating thin glass with cover plate

Info

Publication number: WO2019008496A1
Application number: PCT/IB2018/054886
Authority: WO
Inventors: Mario Arturo MANNHEIM ASTETE; Mauricio Fernando CORNEJO POL; Charles Stephen Voeltzel
Original assignee: Agp America S.A.
Priority date: 2017-07-02
Filing date: 2018-07-02
Publication date: 2019-01-10
Also published as: CO2017009264A1

Abstract

Thin glass is finding increasing application in laminates. However, conventional processing methods have short coming when applied to very thin glass. This invention provides for an improved method of bending and laminating thin glass. Multiple sheets of thin glass are stacked onto a single mold. A cover plate, comprising a sheet of thicker glass, is placed over the sheets of thin glass. As the glass is heated the added mass of the cover plate aids in bending. The bent cover plate of glass can also be used as a pressing plate in the lamination process to prevent wrinkles during lamination. The cover plate can be made of a glass composition having a lower glass transition point than the thin glass and/or of an infrared absorbing composition.

Description

METHOD FOR BENDING AND LAMINATING THIN GLASS WITH COVER PLATE

Field of invention This invention relates to the field of bending and laminating glazings comprising thin glass layers. Background of the invention

In response to the regulatory requirements for increased automotive fuel efficiency as well as the growing public awareness and demand for environmentally friendly products, automotive original equipment manufacturers, around the world, have been working to improve the efficiency of their vehicles.

One of the key elements of the strategy to improve efficiency has been the concept of light weighting. Often times, more traditional, less expensive, conventional materials and processes are being replaced by innovative new materials and processes which while sometime being more expensive, still have higher utility than the materials and processes being replaced due to their lower weight and the corresponding increase in fuel efficiency, further, vehicle glazing has been no exception.

For many years, the standard automotive windshield had a thickness of 5.4 mm. In more recent years, we have seen the typical thickness decrease to 4.75 mm. Today, windshields with a 2.1 mm outer ply, a 1.6 mm inner ply and a 0.76 mm plastic interlayer, totaling just under 4.5 mm in total thickness, are becoming common. This is at or very near the limits of how thin an annealed soda- lime glass windshield can be while still retaining safety and durability characteristics.

Annealed glass is glass that has been slowly cooled from the bending temperature through the glass transition range to relieve any stress in the glass. In a laminate, two sheets of annealed glass are bonded together using a sheet of thermo plastic. If the laminated glass should break, the plastic layer holds the shards of glass together, helping to maintain the structural integrity of the glass. The shards of broken glass are held together much like the pieces of a jigsaw puzzle. A vehicle with a broken windshield can still be operated. On impact, the plastic layer also helps to prevent penetration by the occupant or by objects striking the laminate from the exterior. Heat strengthened glass, with a compressive strength in the range of 70 Mpa, can be used in all vehicle positions other than the windshield. Heat strengthened (tempered) glass has a layer of high compression on the outside surfaces of the glass, balanced by tension on the inside of the glass. When tempered glass breaks, the tension and compression are no longer in balance and the glass breaks into small beads with dull edges. Tempered glass is much stronger than annealed laminated glass. The minimum thickness limits of the typical automotive heat strengthening process are in the 3.2mm to 3.6 mm range. This is due to the rapid heat transfer that is required. It is not possible to achieve the high surface compression needed for a full temper with thinner glass using the typical low pressure air quenching systems.

Glass can also be chemically tempered. In this process, ions in and near the outside surface of the glass are exchanged with ions that are larger. This places the outer layer of glass in compression. The maximum strength of chemically tempered soda lime glass is limited. However, with some other glass compositions, compressive strengths in excess of 700 Mpa are possible. The practice of chemically tempering glass is well known to those of ordinary skill in the art and shall not be detailed here.

Unlike heat tempered glass, chemically tempered glass breaks into shards rather than beads. This property allows for its use in windshields. However, in standard windshield thicknesses chemically strengthened glass would actually be too strong. In the event of a crash and a head impact, the windshield must break, absorbing the energy of the impact rather than the head of the occupant. Therefore, depending upon the tempered strength, thicknesses of 1.6 mm or less must typically be used. The majority of the vehicles on the road today have windshields that were made using the gravity bending process. In this process, the plies of glass that form the laminate are placed onto a ring type mold which supports the glass near the edges, or a full surface mold and heated. The glass softens and sags to shape under the forces of gravity. Sometimes, for more complex shapes, gravity is assisted by pneumatic pressure and/or a partial or full surface pressing. As the plies of glass to be laminated are bent in sets, the surfaces, while they may have substantial variation from windshield to windshield, are a near perfect match. A growing portion of windshields are made by the singlet pressing process. With this process, single sheets of glass are bent using a press to form the glass to shape. The resulting shape is much closer to design and the process can hold tighter tolerances across the surface. Thin glass is difficult to bend using either of these bending process.

When gravity bending is used, due to the low weight of the thin glass sheets, the edges of the thin glass have a tendency to lift and form wrinkles. If the plies of glass are of different compositions, with softening points that are too far apart, it may not be possible to gravity bend the different compositions simultaneously on the same mold as the glass with the lower softening point will become too soft leading to marking and distortion. In this case, the different glass types must be bent separately. Also, due to the low weight of the glass sheets, they do not sag under their own weight in the same predictable and repeatable way that thicker glass does. Another problem is that the glass may begin to sag too soon, before the entire sheet of glass has become soft enough.

Singlet pressing also has problems. The primary one is that as the glass is conveyed through the heating section on rolls it tends to bend under its own weight as it softens resulting in the leading edge hitting the rollers and even falling through. Lamination also presents problems. Due to the high strength of the chemically tempered thin glass sheets, it can be difficult to get the glass to conform to and bond to the other glass layers in the laminate if there is even a small mismatch between the surfaces. This can lead to delamination, trapped air, distortion and wrinkles. This is even more of a problem when cold bending flat or partially bent thin glass layers.

One approach used to solve these problems is cold bending. Cold bending is a relatively new technology. As the name suggest, the glass is bent, while cold to its final shape, without the use of heat. On parts with minimal curvature a flat sheet of glass can be bent cold to the contour of the part. This is possible because as the thickness of glass decreases, the sheets becomes increasingly more flexible and can be bent without inducing stress levels high enough to significantly increase the long term probability of breakage. Thin sheets of annealed soda-lime glass, in thicknesses of about 1 mm, can be bent to large radii cylindrical shapes (greater than 6 m). When the glass is chemically or heat strengthened the glass is able to endure much higher levels of stress and can be bent along both major axis. The process is primarily used to bend chemically tempered thin glass sheets (<=1 mm) to shape.

The glass to be cold bent is placed with a bent glass layer and with a plastic bonding layer placed between the glass to be cold bent and the bent glass layer. The assembly is placed in what is known as a vacuum bag. The vacuum bag is an airtight set of plastic sheets, enclosing the assembly and bonded together it the edges, which allows for the air to be evacuated from the assembly and which also applies pressure on the assembly forcing the layers into contact. The assembly, in the evacuated vacuum bag, is then heated to seal the assembly. The assembly is next placed into an autoclave which heats the assembly and applies high pressure. This completes the cold bending process as the flat glass at this point has conformed to the shape of the bent layer and is permanently affixed. The cold bending process is very similar to a standard vacuum bag/autoclave process, well known in the art, with the exception of having an unbent glass layer added to the stack of glass.

As can be appreciated, a better process would be beneficial. Brief summary of the invention. The present invention discloses a method for simultaneously bending multiple sheets of thin glass using a single mold. The mold may be of the periphery support ring type, as shown in Figures 1, 2 and 3, or of the full surface type. A layer or layers of glass, required for the final laminate may be required to support the thin glass layers, is placed onto the mold prior to the thin glass. The sheets of thin glass are then placed onto the mold. The number of thin glass layer that can be bent at the same time will depend upon the type of mold used, the thickness of the glass, the glass composition and the size and the complexity of the shape.

A cover plate comprising a sheet of thicker glass, is then placed over of the stack of thin glass. As the glass is heated and begins to soften, the added mass of the thicker glass cover plate aids in the bending of the thin glass sheets. The contact force between the thin glass and the mold is increased by the added weight. The added weight of the cover plate holds the thin glass layers in place preventing wrinkling and preventing the thin glass from starting to sag too soon. The bending can be modified by adjusting the thickness of the cover plate as may be required. Additionally, most windshield bending molds use electric radiant heating in the roof of the furnace. The cover plate absorbs the radiant heat. The heat is then transferred to the thin glass layers by conduction, reducing thermal gradients in the thin glass and potential residual stress in the thin glass. The more uniform heating improves the dimensional quality of the finished part as bending tends to be more accurate and repeatable.

A glass composition as cover plate has a lower glass transition temperature than the thin glass that may be used so as to allow the cover plate to soften before the thin glass does. The thin glass will be subject to uniform pressure from the soft cover plate when the thin glass reaches its glass transition point. An infrared absorbing (IR) glass composition may be used for the cover plate. With an IR absorbing composition the cover plate will heat at a faster rate and reach a higher temperature that it would with a non-infrared absorbing composition in the same family of glass (soda-lime as an example). If the thin glass and the cover glass have the same glass transition temperature, the infrared absorbing cover plate will reach its glass transition temperature before the thin glass.

The cover plate can be one of the layers of the final laminate or not. After bending, the bent cover plate can be again be used in the lamination process. When the thin glass is not one of the inside layers of the laminate, there is a tendency for wrinkles to form during lamination. The bent cover plate can be placed with its surface adjacent to the thin glass. The cover plate serves to distribute the applied force preventing the thin glass from wrinkling during lamination. This approach can be used to cold bend the thin glass as shown in Figure 4A. With cold bending, the thin glass is either flat or only partially bent to the final shape by means of thermal bending when the glass is assembled into a laminate. Vacuum and pressure, applied during the lamination process, to bend the flat or partially bent thin glass to its final shape where the shape is maintained by the plastic bonding interlayer.

It is also disclosed a laminate produced by the methods of the present invention. The method of the invention has some advantages as follows:

• Prevents thin glass wrinkles during bending.

• Prevents thin glass wrinkles during lamination.

• Holds the thin glass in place during bending preventing it from sagging too soon. Reduces thermal gradients.

Reduces residual stress.

Improves dimensional surface control.

Provides and efficient means of bending thin glass.

Allows for bending of different glass compositions for use in the same laminate.

Brief description of the drawings

Figure 1 A shows the corner detail of a bending mold with flat thin glass and cover plate.

Figure IB shows the bending mold with five flat thin glass layers and cover plate.

Figure 2A shows the cross section of the five flat thin glass and cover plate.

Figure 2B shows the corner detail of bending mold with five bent thin glass and cover plate.

Figure 2C shows an isometric view of the bending mold with five bent thin glass and cover plate.

Figure 3A shows the cross section of the five flat thin glass and bending mold female ring.

Figure 3B shows the corner detail of bending mold with five bent glass support layer, thin glass layers and cover plate.

Figure 3C shows the bending mold with five bent glass support layer, thin glass layers and cover plate.

Figure 4A shows the exploded view of the laminate with cold bent thin glass layer.

Figure 4B shows the exploded view of laminate with thermally bent thin glass layer.

Figure 5 shows the laminate cross-section.

Reference numerals of drawings

2 Glass

4 Thin glass

6 Plastic interlayer

8 Support

10 Cover Plate

12 Bending mold base

14 Bending mold female ring

101 Exterior side of glass layer 1 , number one surface

102 Interior side of glass layer 1, number two surface.

103 Exterior side of glass layer 2, number 3 surface.

104 Interior side of glass layer 2, number 4 surface.

201 Vehicle exterior layer

202 Vehicle interior layer Detailed description of the invention

There are many materials that are classified as glass. Glass, as used in this document, includes but is not limited to: the common soda-lime variety typical of automotive glazing as well as aluminosilicate, lithium aluminosilicate, borosilicate, glass ceramics, and the various other inorganic solid amorphous compositions which undergo a glass transition and are classified as glass included those that are not transparent. Also included are glass like ceramic materials.

There are a wide variety of differences in the glass transition temperature range between the various types of glass. The starting point is to pick a glass that has a glass transition range that is sufficiently higher than the glass type that will be bent in the final product. At the forming temperature of the lower temperature glass, the higher temperature glass must retain its shape and strength. In the case of ordinary soda-lime glass or borosilicate glass, an example, certain formulations of lithium aluminosilicate glass meet this criteria.

The present invention is related to a method for simultaneously bending multiple sheets of thin glass by using a single mold. The mold may be of the periphery support ring type, as shown in Figures 1, 2 and 3 (3A,3B and 3C), or may be a full surface type. A layer or layers of glass, required for the final laminate or as required to support the thin glass layers, is placed onto the mold which in some embodiments may be prior to the thin glass. The sheets of thin glass are then placed onto the mold. The number of thin glass layers that can be bent at the same time will depend upon the type of mold used, the thickness of the glass, the glass composition, the size and the complexity of the shape.

Also, a cover plate comprising a sheet of thicker glass, is then placed over of the stack of thin glass. As the glass is heated and begins to soften, the added mass of the thicker glass cover plate aids in the bending of the thin glass sheets. The contact force between the thin glass and the mold is increased by the added weight. The added weight of the cover plate holds the thin glass layers in place preventing wrinkling and preventing the thin glass from starting to sag too soon. The bending can be modified by adjusting the thickness of the cover plate as may be required. In the drawings and discussion, the following terminology is used to describe the configuration of a laminated glazing. Figure 5, shows a typical automotive laminate comprised of two layers of glass. It should be understood that additional layers can be also part of a laminated automotive glass, for which the present invention can also be part of. Referring to Figures 5A and 5B, the exterior or outer, 201 and interior or inner, 202 that are permanently bonded together by a plastic layer 6 (interlayer). The glass surface that is on the exterior of the vehicle is referred to as surface one 101 or the number one surface. The opposite face of the exterior glass layer 201 is surface two 102 or the number two surface. The glass 2 surface that is on the interior of the vehicle is referred to as surface four 104 or the number four surface. The opposite face of the interior layer of glass 202 is surface three 103 or the number three surface. Surfaces two 102 and three 103 are bonded together by the plastic layer 4.

The plastic bonding layer 4 (interlayer) has the primary function of bonding the major faces of adjacent layers to each other. The material selected is typically a clear thermoset plastic. For automotive use, the most commonly used bonding layer 4 (interlayer) is polyvinyl butyral (PVB). PVB has excellent adhesion to glass and is optically clear once laminated. It is produced by the reaction between polyvinyl alcohol and n-butyraldehyde. PVB is clear and has high adhesion to glass. However, PVB by itself, it is too brittle. Plasticizers must be added to make the material flexible and to give it the ability to dissipate energy over a wide range over the temperature range required for an automobile. Only a small number of plasticizers are used. They are typically linear dicarboxylic esters. Two in common use are di-n-hexyl adipate and tetra-ethylene glycol di-n-heptanoate. A typical automotive PVB interlayer is comprised of 30-40% plasticizer by weight. In addition to polyvinyl butyl, ionoplast polymers, ethylene vinyl acetate (EVA), cast in place (CIP) liquid resin and thermoplastic polyurethane (TPU) can also be used. Automotive interlayers are made by an extrusion process with has a thickness tolerance and process variation. As a smooth surface tends to stick to the glass, making it difficult to position on the glass and to trap air, to facilitate the handling of the plastic sheet and the removal or air (deairing) from the laminate, the surface of the plastic is normally embossed contributing additional variation to the sheet. Standard thicknesses for automotive PVB interlayer at 0.38 mm and 0.76 mm (15 and 30 mil). A glass composition as cover plate has a lower glass transition temperature than the thin glass that may be used so as to allow the cover plate to soften before the thin glass does. The thin glass will be subject to uniform pressure from the soft cover plate when the thin glass reaches its glass transition point. An infrared absorbing (IR) glass composition may be used for the cover plate. With an IR absorbing composition the cover plate will heat at a faster rate and reach a higher temperature that it would with a non-infrared absorbing composition in the same family of glass (soda-lime as an example). If the thin glass and the cover glass have the same glass transition temperature, the infrared absorbing cover plate will reach its glass transition temperature before the thin glass. Infrared reflecting films include both metallic coated plastic substrates as well as organic based non-metallic optical films which reflect in the infrared. Most of the infrared reflecting films are comprised of a plastic film substrate having an infrared reflecting layered metallic coating applied.

The cover plate can be one of the layers of the final laminate or not. After bending, the bent cover plate can be again be used in the lamination process. When the thin glass is not one of the inside layers of the laminate, there is a tendency for wrinkles to form during lamination. The bent cover plate can be placed with its surface adjacent to the thin glass. The cover plate serves to distribute the applied force preventing the thin glass from wrinkling during lamination. This approach can be used to cold bend the thin glass as shown in Figure 4A. With cold bending, the thin glass is either flat or only partially bent to the final shape by means of thermal bending when the glass is assembled into a laminate. Vacuum and pressure, applied during the lamination process, to bend the flat or partially bent thin glass to its final shape where the shape is maintained by the plastic bonding interlayer. The glass layers may be annealed or strengthened. There are two processes that can be used to increase the strength of glass. They are thermal strengthening, in which the hot glass is rapidly cooled (quenched) and chemical tempering which achieves the same effect through an ion exchange chemical treatment. Heat strengthened, full temper soda-lime float glass, with a compressive strength in the range of at least 70 MPa, can be used in all vehicle positions other than the windshield.

In the chemical tempering process, ions in and near the outside surface of the glass are exchanged with ions that are larger. This places the outer layer of glass in compression. Compressive strengths of up to 1, 000 MPa are possible. The typical methods involved submerging the glass in a tank of molten salt where the ion exchange takes place. The glass surface must not have any paint or coatings that will interfere with the ion exchange process.

Referring to the Figure 1A, IB, 2A, 2B the present invention is related to a method for bending thin glass comprising the steps of: a) providing a bending mold and a cover plate;

b) providing at least one sheet of thin glass 4 onto the mold 12;

b) applying the cover plate 10 over top of the thin glass sheets 4;

c) heating the cover plate to at least the softening point of the thin glass 4; and d) allowing the glass to sag to the desired shape.

Additionally, the present invention discloses a method for laminating thin glass layers comprising the steps of: a) providing at least one thin glass layer and placing at least one additional thin glass layer;

b) assembling the at least two thin glass layers and plastic bonding interlayers that are to be a part of the final laminate;

c) placing a bent cover plate produced by the method of claim 1 such that one of the cover plates major faces is in contact with the corresponding major face of the thin glass layer;

d) enclosing the assembled laminate and evacuating the air from the enclosure; and e) applying heat and pressure to the assembly in a standard lamination process.

While a vacuum bag process is used in the discussion and the preferred embodiments, other methods such as a vacuum ring and other means may be used and are considered as equivalent and do not deviate from the intend of the invention. During the lamination process, the laminate is treated with heat and pressure. At the higher temperatures and pressure, the plastic interlayer will melt and flow to accommodate the thickness of the insert. Embodiment 1:

Referring to Figure 2B, a first embodiment corresponds to a bending mold female ring 14 which is first loaded with 5 sheets of thin 0.7 mm clear aluminosilicate glass 2 cut to size. A 6 mm soda lime glass cover plate 10 is then placed over top of the thin glass 4. The cover plate 10 is cut slightly larger than the thin glass 4 to make sure that the thin 4 glass is completely covered. After bending, the thin glass 4 is chemically tempered 2.1 mm soda-lime glass 2 is press bent to shape separately. A laminate is prepared comprising the 2.1 mm bent soda-lime glass 2 outer layer 201 and with a 0.7 mm aluminosilicate inner layer 202. A layer of 0.76 mm transparent polyvinyl butyl (PVB) plastic interlayer 6 is placed between the two glass layers 2. The bent cover plate 10, covered with a layer of fine mesh fiberglass cloth to prevent scratching, is placed in contact with the surface 204 of the 0.7 thin glass 4 layer 202. The assembled laminate and cover plate 10 are placed in a plastic "bag," the bag is sealed and a vacuum is drawn. This bag is then processed through a standard autoclave process where heat and pressure are applied. Upon completion of the lamination processed, the cover plate 10 can be reused.

Embodiment 2: In a second embodiment a full surface female mold is first loaded with 10 sheets of thin 0.4 mm clear aluminosilicate glass 4 cut to size. An 8 mm infra-red absorbing soda lime glass cover plate 10 is then placed over top of the thin glass 4. After bending, the thin glass 4 is chemically tempered. 2.1 mm soda-lime glass 2 is press bent to shape separately. A laminate is prepared comprising the 2.1 mm bent soda-lime glass 2 outer layer 201 and with the 0.4 mm aluminosilicate inner layer 202. A layer of 0.76 mm transparent polyvinyl butyl (PVB) plastic interlayer 6 is placed between the two glass layers 2. The bent cover plate 10, covered with a layer of fine mesh fiberglass cloth to prevent scratching, is placed in contact with the surface 204 of the thin glass 4 layer 202. The assembled laminate and cover plate 10 are placed in a plastic "bag", the bag is sealed and a vacuum is drawn. This bag is then processed through a standard autoclave process where heat and pressure are applied. Upon completion of the lamination process, the cover plate 10 can be reused. Embodiment 3:

In a third embodiment a ring type female mold 14 is first loaded with 4 sheets of thin 1.2 mm clear aluminosilicate glass 4 cut to size. A 6 mm solar green soda lime glass cover plate 10 is then placed over top of the thin glass 4. The cover plate 10 is cut slightly larger than the thin glass to make sure that the thin glass is completely covered. After bending, the thin glass 4 is chemically tempered. 2.1 mm soda-lime glass 2 is press bent to shape separately. A laminate is prepared comprising the 2.1 mm bent soda-lime glass 2 outer layer 201 and with the 1.2 mm aluminosilicate inner layer 202. A layer of 0.76 mm transparent polyvinyl butyl (PVB) plastic interlayer 6 is placed between the two glass layers 2. The bent cover plate 10, covered with a layer of fine mesh fiberglass cloth to prevent scratching, is placed in contact with the surface 204 of the 0.7 thin glass 4 layer 202. The assembled laminate and cover plate 10 are placed in a plastic "bag", the bag is sealed and a vacuum is drawn. This bag is then processed through a standard autoclave process where heat and pressure are applied. Upon completion of the lamination process, the cover plate 10 can be reused.

Embodiment 4:

In a forth embodiment, the method used to produce bend the laminate of embodiment 2 is modified with the addition of a 3 mm layer of aluminosilicate glass 2 placed on the mold to provide additional support 8 and to prevent marking of the thin glass. The support 8 layer is discarded after bending.

Embodiment 5:

In a fifth embodiment a bending mold female ring 14 is first loaded with 5 sheets of thin 1.2 mm clear aluminosilicate glass 4 cut to size. A 6 mm soda lime glass cover plate 10 is then placed over top of the thin glass 4. The cover plate 10 is cut slightly larger than the thin glass 4 to make sure that the thin glass 4 is completely covered. After bending, the 1.2 mm thin glass 4 is chemically tempered. A sheet of 0.4 mm aluminosilicate glass is cut to size and then chemically tempered while flat. A laminate is prepared comprising the 1.2 mm bent aluminosilicate 4 outer layer 201 with a 0.4 mm aluminosilicate inner layer 202. A layer of 0.76 mm transparent polyvinyl butyl (PVB) plastic interlayer 6 is placed between the two glass layers 2. The bent cover plate 10, covered with a layer of fine mesh fiberglass cloth to prevent scratching, is placed in contact with the flat surface 204 of the 0.4 thin glass 4 layer 202. The assembled laminate and cover plate 10 are placed in a plastic "bag", the bag is sealed and a vacuum is drawn. This bag is then processed through a standard autoclave process where heat and pressure are applied. The pressure and vacuum bend the flat glass to the desired bent shape. Upon completion of the lamination process, the cover plate 10 can be reused.

The forms of the invention shown and described in this specification represent illustrative preferred embodiments and it is understood that various changes may be made without departing from the spirit of the invention as defined in the following claimed subject matter.

Claims

1. A method for bending thin glass comprising the steps of: a) providing a bending mold and a cover plate;

b) providing at least one thin glass onto the mold;

c) applying a cover plate over top of the thin glass;

d) heating the cover plate to at least the softening point of the thin glass; and e) allowing the glass to sag to the desired shape.

2. The method of Claim 1 further comprising the step of placing one or more sheet of glass onto the mold prior to the thin glass.

3. The method of Claim 1 further comprising the step of chemically tempering the thin glass.

4. The method of Claim 1 wherein a full surface female mold is used.

5. The method of Claim 1 wherein female ring type mold is used.

6. The method of Claim 1 wherein the thin glass has a thickness of less than about 1.6 mm.

7. The method of Claim 1 wherein the size if the cover plate is slightly larger than the thin glass.

8. The method of Claim 1 wherein the cover plate is comprised of a glass composition having a lower glass transition temperature than that of the thin glass.

9. The method of Claim 1 wherein the cover plate is comprised of an infrared absorbing glass composition.

10. The method of Claim 1 wherein the thin glass is an aluminosilicate glass composition.

11. The method of Claim 1 wherein the thin glass is a borosilicate glass composition.

12. A glass lamination method for laminating thin glass layers, comprising the steps of: a) providing at least one thin glass layer and placing at least one additional thin glass layer;

13. The method of Claim 12 wherein the thin glass is flat.

14. The method of Claim 12 wherein the thin glass is partially bent.

15. The method of Claim 12 wherein the thin glass is cold bent to the desired shape.

16. The laminate produced by the method of Claim 1.

17. The laminate produced by the method of Claim 12.

18. A vehicle comprising the glazing of Claim 16.

19. A vehicle comprising the glazing of Claim 17.