GB2355995A

GB2355995A - Architectural glass block element

Info

Publication number: GB2355995A
Application number: GB9925886A
Authority: GB
Inventors: Rodney Bender
Original assignee: Swansea Institute of Higher Education SIHE
Current assignee: Swansea Institute of Higher Education SIHE
Priority date: 1999-11-02
Filing date: 1999-11-02
Publication date: 2001-05-09
Anticipated expiration: 2019-11-02
Also published as: GB2355995B; GB9925886D0

Abstract

The element comprises layered glass strata, each stratum (2a, 2b, 2c etc) having a pair of spaced major faces and edges between said major faces, adjacent major faces of said strata being fused together to form a monolithic glass block having at least some of said edges exposed and visible.

Description

2355995 Architectural Elements The present invention is concerned with

architectural elements and, specifically, architectural elements of glass.

Glass is an integral element of many architectural features, typically being provided in the form of float glass (in the form of sheets or panes) or in the form of bricks which generally have voids therein. The difficulty with such glass architectural elements is that they give the architect very little flexibility in the way in which the elements can he used.

It is an object of the invention to provide a glass architectural element which can give a different type of aesthetic effect and optical effect compared to conventional glass sheets or panes, and to glass blocks.

According to the invention, therefore, there is provided an architectural element comprising a plurality of layered glass strata, each stratum having a pair of spaced major faces, and edges between said major faces, adjacent major faces of said strata being fused together to form a monolithic glass block having at least some of said edges exposed and visible.

The strata comprise stacked sheets of glass laid face to face; the thickness of each sheet is typically significantly less than the length and breadth dimensions of each individual sheet.

The resulting architectural element provides interesting optical effects because each individual stratum provides a guide for passage of light from one edge of the block to a longitudinally spaced edge which is exposed and visible. It is preferred that the edge to which a respective stratum is exposed to light is longitudinally spaced from an edge which is exposed and visible. When the relevant stratum is rectangular, these two edges may be at opposed ends of the relevant stratum.

It is preferred that the glass strata are each of glass of an architectural quality such as a conventional silicate glass. Preferably, each of the individual strata is produced by a float glass process of type known per se, in which glass is formed in relatively thin layers by cooling a respective layer of molten glass, while the latter is floating on a layer of molten tin. Typically the individual strata have thicknesses of the order of 4 to 14mm. The architectural element according to the invention is typically made from about 4 to 12 layered glass strata.

The present invention further comprises a method of making an architectural element, which comprises the steps of:

(a) forming a layered stack of a plurality of glass sheets, in which each sheet has a pair of spaced major faces and a major face of each sheet is placed in contact with a major face of an adjacent stack; (b) heating the stack at sufficiently high temperature that each individual sheet is fused to an adjacent sheet, without substantial deformation of the alass, so as to produce a monolithic glass block in which at least some of the edges of the individual sheets are exposed and visible.

Preferably, the stack is heated at a temperature of at least 60011C. If the temperature is too low, fusing of individual sheets will not take place.

It is further preferred that the fusing temperature is not more than 700cC. If temperatures are too high, then substantial deformation of the individual sheets may take place and, furthermore, edge detail of the individual sheets may be lost.

It is further preferred that the individual sheets are cleaned prior to forming the layered stack of sheets of glass. Such cleaning may be either by automated cleaning machine or by hand. It is further preferred that the individual sheets forming the stack have major faces which are substantially similar in shape and size. It is further preferred that the individual sheets have substantially the same thickness.

The sheets can be stacked in layers of at least six, such as up to twelve. The sheets typically have a thickness of from 2 to 12mm.

It is particularly preferred that the layered stack is heated according to the invention in an electric kiln; gas fired kilns are not preferred because they tend to heat the glass too rapidly leading to thermal shock and they are difficult to control during the cooling cycle.

The optimum way of loading the kiln may be determined by the nature of the kiln (for example, whether it is top heated, side heated or a combination of both). In any case, edges of layered stacks (or of individual sheets) should not touch in the kiln and there should preferably be a spacing between such stacks such as for example about 1cm.

The layered stack of glass sheets is preferably loaded into the kiln while the latter is cool, and the oven then heated relatively slowly up to an upper or maximum temperature (known as the soak temperature), the magnitude of which will depend on the type of glass employed.

Typically, when one layer of glass sheet, each consisting of ten layers of 4mm sheets is used, then the temperature is increased at a rate of about 15011C per hour, until a temperature of about 6500C is reached (known as the upper soak temperature).

once the upper soak temperature has been reached, the temperature is preferably maintained for a predetermined period, such as at least 90 minutes (preferably at least two hours). In this way, the glass sheets can soften and bond together without losing their edge profile.

Following the heating at the upper soak temperature, for the required time, the glass is then typically cooled to its annealing point or upper annealing point; in the case of float glass conventionally available from Pilkingtons, the upper annealing point is about 5500C.

The glass blocks may then be held at the anneal soak temperature for a predetermined time; this time depends upon factors such as the type of glass, the number of layers in each stack, the number of stacks in the kiln, the configuration of the kiln and the internal volume of the kiln, amongst others.

After an anneal soak, the glass blocks are typically allowed to cool to a temperature about 1001C below the annealing temperature (the stress point or lower annealing point). The rate of cooling is usually determined by multiplying the anneal soak time, by a factor of 2.5.

Once the annealing point is reached, the glass blocks are again cooled as rapidly as possible, while still avoiding thermal shock. Such rapid cooling may be aided by forced air in the kiln.

Once the temperature of the cooled blocks has reached about 400C, they are preferably removed from the kiln. They may then be subject to quality control, for example, by checking for stress using a polarising filter or a grazing angle surface polarimeter. In the above process, cooling the glass too rapidly may produce unacceptable levels of tension in the glass blocks, with the risk of spontaneous fracture during or after cooling.

The resulting cooled and checked block is suitable for use as an architectural element; for example, it may be used together with bricks or blocks as part of a wall construction. The present invention therefore comprises a building construction, which includes a plurality of construction elements and at least one architectural element according to the invention included therein, so as to permit light to pass through the structural element.

The glass making up the layered glass strata is preferabiv transparent; when the strata are layered in the architectural element according to the invention, light _JS permitted to channel and pass through the ind-ividuastrata, to form pleasing aesthetic effects.

The present invention will now be described in more detail with reference to the accompanying drawing, which is a schematic representation of an architectural elemen-according to the invention.

The element comprises a block 1, having a stack of layered' glass strata, 2a, 2b, 2c, 2d, 2e, 2f and 2g. Each stratum is substantially rectangular and has a first edge to be exposed to light and a second edge spaced from the firsz edge, through which light incident on the first edge can be viewed.

Claims

Claims:

i An archii--ec--ural element comprising a plurality of layered glass strata, each stratum having a pair of spaced major faces and edges between said major faces, adjacent major faces of said strata being fused together to form a monolithic glass block having at least some of said edges exposed and visible.
2. An architectural element according to claim 1, wherein the strata comprise stacked sheets of glass laid face to face.
3. An architectural element according to claim 2, wherein the thickness of each individual sheet is significantly less than either the length or breadth dimensions.
4. An architectural element according to any of claims 1 to 3, wherein the exposed edge of a respective stratum is longitudinally spaced from a further edge of the stratum.
5. An architectural element according to any one of the preceding claims, wherein the glass strata are each of silicate glass.
6. An architectural element according to any one of the preceding claims, wherein each individual stratum has been produced by a float glass process.
7. An architectural element according to any one of the preceding claims, wherein each individual scracum has a thickness of the order of 4 to 14 mm.
8. An architectural element according to any one of the preceding claims, which includes 4 to 12 in number of said layered glass strata.
9. A method of making an architectural element, which comprises the steps of:

(a) forming a layered stack of plurality of glass sheets each having a pair of spaced major faces, a major face of each said sheet being in contact with a major face of an adjacent sheet; (b) heating the stack at sufficiently high temperature that each individual one of said sheets is fused to an adjacent one of said sheets, without substantial deformation of the glass, so as to produce a monolithic glass block in which at least some of the edges of the individual sheets are exposed and visible.
10. A method according to claim 9, wherein step (b) is at a temperature of at least 600'C, so as to fuse individual sheets.
11. A method according to claim 9, wherein the temperature is not more than 7001C.
12. A method according to any of claims 9 to 11, wherein the individual sheets are cleaned prior to step (a).
13. A method according to any of claims 9 to 12, wherein the individual sheets forming the layered stack have major faces which are substantially similar in shape and size.
14. A method according to any of claims 9 to 13, wherein the thickness of each individual sheet is the same.
15. A method according to any of claims 9 to 14, wherein the sheets are stacked in layers of at least six in number.
16. A method according to any of claims 9 to 15, wherein each individual stratum has a thickness is in the range 2 to 12 mm.
17. A method according to any of claims 9 to 16, wherein step (b) is carried out in an electric kiln.
18. A method according to claim 17, wherein in step (b) the layered stack of glass sheets is loaded into an oven while said oven is cool, and the oven then heated slowly up to a soak temperature for said glass.
19. A method according to claim 18, wherein the oven temperature is increased at a rate of about 1500C per hour, until the soak temperature is reached.
20. A method according to claim 19 wherein the soak temperature is maintained for a period of 90 to 120 minutes.
21. A method according to claim 20 wherein following step (b) the stack is cooled to the annealing point of said glass.
22. A method according to claim 21, wherein the cooled blocks are removed from the oven. once their temperature has reached about 401C.