GB2415458A

GB2415458A - Fire resistant glazing

Info

Publication number: GB2415458A
Application number: GB0414217A
Authority: GB
Inventors: Anthony Lee Hughes
Original assignee: Epwin Group PLC
Current assignee: Epwin Group PLC
Priority date: 2004-06-24
Filing date: 2004-06-24
Publication date: 2005-12-28
Also published as: GB0414217D0

Abstract

A glazed door or window comprises a window frame or door 10 having an aperture containing a glazing panel 90, first 30 and second 40 opposing glazing beads of plastic material hold the glazing panel 90 within the aperture and are fixed together with a fixing element 130. At least one fire resisting intumescent member 70, 110 is provided between the window frame or door 10 and the glazing panel 90. A first fire resistant member 110 may be provided on an edge of the glazing panel 90 and a second fire resistant member 70 on an edge of the aperture. The fire resistant members 70, 110 may be provided on each edge of the glazing panel 90 and the aperture. The glazing beads 30, 40 may be pre-moulded plastics components and may have lugs 140, 150 on their facing sides, the fixing element 130 being fixed to the lugs 140, 150. A method of making such a glazed door or window is also provided.

Description

24 1 5458 Fire Resistant Glazing The present invention relates to a glazed

door or window and in particular one which is intended to have a degree of fire resistance. Although the invention will be described primarily with reference to doors, it may also be applied to windows.

Doors made from a variety of materials may be glazed to create one or multiple vision panels within the door for aesthetic or safety reasons.

Regulatory/legislative requirements for buildings require that some doors be able to resist fire for a prescribed period of time. Doors must be tested in accordance with relevant industry standards to determine and provide evidence of the performance level achieved.

Vision panels in fire resisting doors require a retention system for the glazing capable of resisting fire in test conditions. Existing fire doors utilise a variety of methods and materials for glazing retention.

Present glazing retention methods for fire resisting doors incorporate either a timber or metal glazing bead.

Typically, the bead must be of a certain shape and size and of specific material properties to achieve the required fire resistance. For example with timber, which is combustible, the density is important as this relates directly to the char rate of the timber when exposed to fire.

In combination with glazing retention beads, fire resisting inturnescent materials may also be used between the glass and the bead and sometimes between the glass and the door to either increase the time period for fire resistance or as an alternative to using large beads.

Intumescent materials expand in size when exposed to high temperatures and are used to create pressure and retain the glazing within the door in fire test conditions.

Examples of intumescent materials include graphite, sodium silicate or ammonium phosphate and one or a combination of these may be used in a variety of shapes and size.

A disadvantage of current glazing retention systems is that current methods do not incorporate low maintenance materials which are particularly important for external applications where weather resistance, maintenance and appearance are of importance. Metals usually need to be coated, and timber needs to be coated or treated or both. Coatings need to be re-applied periodically to maintain the material resistance to weather and atmospheric conditions.

Also, metal and timber glazing beads need to be cut to size or jointed, as well as fixed using a method which requires fixing positions to be determined by the fabricator of the door product. Fixings are fixed through the bead into the material of the door. Failure to cut and fix beads in the exact manner - i.e. quantity and positions - in which they were originally tested for fire resistance may create a risk of glass retention failure in the event of a fire.

Accordingly, at its most general, the present invention proposes using a glazing retention bead formed of a plastics material and providing at least one fire resistant intumescent member between the glazing panel and the door or frame of the window.

A first aspect of the present invention may provide a glazed door or window having: a glazing cassette comprising first and second opposing beads on opposite sides of the door or window, said beads being formed of a plastics material, and a fixing element fixing said first and second beads together; a glazing panel held between said first and second beads; and a fire resisting intumescent member between the door or frame of the window and the glazing panel.

The fire resisting intumescent member may be provided on an edge of the glazing panel itself or on an inside edge of the door or window aperture which receives the glazing panel. Preferably there are two fire resisting intumescent members, one mounted on an edge of the glazing panel and one mounted on an inside edge of a glazing receiving aperture of the door or window frame.

Preferably fire resisting intumescent members are mounted on at least two opposite edges of the glazing panel, most preferably there is a fire resisting intumescent member on each edge of the glazing panel. Preferably fire resisting intumescent member are mounted on at least two opposing inside edges of the door or window frame aperture, most preferably on each edge so that the interior of the aperture is lined with a fire resisting intumescent material. As mentioned above, in the event of a fire the intumescent material expands and thus helps preserve the integrity of the door or window by pressing against and retaining the glazing panel.

The beads are made from plastics material.

Therefore they do not require coating to provide protection from atmospheric conditions or weather and will not degrade under normal conditions. In contrast timber beads may rot and metal beads may corrode and thus require periodic application of protective coatings.

Furthermore, the fire resisting intumescent member is able to expand in the event of a fire, so as to secure the glazing panel in place.

Another advantage of the use of plastics material beads is that they can be moulded easily and provided in a pre-determined standard size. Preferably each of the beads is a pre-moulded plastics component. Most preferably, each bead is a single integral piece. If pre-moulded beads are used it is no longer necessary to cut them to size, on fitting to the door or window. In this way the risk of gaps at the joints or areas in size calculation can be significantly reduced or even eliminated. Thus, the risk of glass retention failure in the event of a fire is reduced.

The glazing panel may be any suitable glazing material, for example, glass.

The fixing element of the glazing cassette need not be made up of a plastics material. It may for example be a (e.g. metal) screw for fixing the first and second beads together; this has the advantage that the spacing of the first and second beads or tightness of fit to the door or window frame, can be adjusting by turning of the screw. A significant difference between the present above described glazing set and glazing used on previous fire resistant doors is that the first and second beads 1() are fixed to each other, rather than directly to the door. Thus the beads' fixing positions can be predetermined, as they are not dependent on the door, and this reduces the risk of them being fixed in different positions to that in which they were tested for fire resistance. Preferably, one or both of the beads has a lug to which the fixing means can be fixed. In one embodiment, a first bead has a fixing lug and a second bead has an aperture through which the fixing element can be inserted and fixed to the fixing lug of the first bead. Preferably, both beads have fixing lugs on their inner sides (the sides facing the door or window) and the lugs are fixed together by driving a screw through each.

A second aspect of the present invention may provide a method of making a glazed door or window comprising the steps of fixing together first and second plastics material beads on either side of a door or a window frame with a fixing element such that the beads receive and hold a part of a glazing panel between them and providing at least one fire resisting intumescent member between the door or frame of the window and the glazing panel.

The method may comprise further steps of providing any of the components or preferred features of the first aspect of the invention and (where appropriate) assembling them into the door or window. The door, window, beads and glazing panel may have any of the features of the first aspect of the invention.

An embodiment of the present invention will now be described with reference to the accompanying drawings in which: Fig. 1 is a perspective view of a door having an aperture for receiving a glazing panel and first and second beads for retaining the glazing panel.

Fig. 2 is a cross sectional view of a part of the door surrounding the aperture and shows intumescent material lining the aperture) Fig. 3 is a cross-sectional view showing top and bottom ends of a glazing panel and intumescent material surrounding these ends; and Fig. 4 is a crosssectional view of the glazing cassette and a section of the door and glazing panel near one edge of the door's aperture.

Fig. 1 shows a door 10 having an aperture 20 for receiving a glazing panel such as that shown in Fig. 3.

The glazing panel (not shown in Fig. 1) is fixed to the door 10 by a first (outer) bead 30 and a second (inner) bead 40. Both the inner and outer beads 30, 40 are formed of a plastics material, such as ABS, polycarbonate, PVC-u, polypropylene or a blend of these materials. The beads 30, 40 are both integral pre moulded components. The inner bead 40 has a plurality of apertures 50 through which respective fixing elements can be inserted to fix the inner aperture 40 to the outer aperture 30.

Fig. 2 is a cross-section showing parts of the door surrounding upper 60 and lower 70 edges of the aperture 20. Both of these edges are lined with a layer of fire resisting intumescent material 80. The side edges of the aperture (not shown in Fig. 2) may also be lined with fire resisting intumescent material which may for example be graphite, sodium silicate, ammonium phosphate or a combination of these materials.

Fig. 3 is a cross-section of the upper and lower l5 edges of a glazing panel 90, which is formed of glass.

The upper and lower edges 100, 110 of the glazing panel are received in elongate fire resisting intumescent members 120, each of which has a recessed channel for receiving and surrounding an end of the glazing panel 90.

Additionally, the side edges of the glazing panel 90 may also be lined in fire resisting intumescent members. The fire resisting intumescent material of these members may be the same as that for the layer 80 discussed above.

Fig. 4 is a cross-sectional view of a part of the door 10, with a glazing set and glazing panel 90 installed. As described above the lower end of the glazing panel 90 is encapsulated in and received by a fire resisting intumescent member 110. Also as described above, the lower edge of the aperture 20 for receiving the glazing panel 90 is coated with a layer of fire resisting intumescent material 70.

The glazing cassette comprises first and second plastics material beads 30, 40 and a fixing element 130.

The beads 30, 40 are positioned on opposite sides of the door and are fixed together by the fixing element 130, which in this embodiment is a screw. Each of the bead 30, 40 has a respective fixing lug 140, 150 on an inner side thereof. Both of the beads are pre-formed by a moulding process. The fixing lugs 140, 150 are formed as an integral part of their respective beads 30, 40 during the moulding process. The beads 30, 40 are fixed together by inserting screw 130 through aperture 50 and screwing the screw through the plastics material so that it extends through and fixes together both of the fixing l5 lugs 140, 150. In this way the beads 30 and 40 are fixed together and indirectly fixed to the door 10. The lower end of the glazing panel 90 is received in the gap between the upper end of the beads 30, 40. As can be seen in Fig. 4, the fire resisting intumescent member 110 surrounding this end of the glazing panel 90 is also received between the beads 30, 40. The upper end of the beads 30, 40 presses against opposite sides of the intumescent material 110 and thus holds the glazing panel in place.

In alternative embodiments, the door could have only the intumescent material layers 70 and not the intumescent material members 110 or vice versa. If the intumescent material member 110 is not present, then the upper ends of the first and second beads 30, 40 press directly against and hold the lower end of the glazing panel 90 in place. While an embodiment of the invention has been described above with reference to a door, the present invention could also be applied to a window as will be appreciated by a person skilled in the art.

Claims

Claims 1. A glazed door or window having: a glazing cassette comprising

first and second opposing beads on opposite sides of the door or window, said beads being formed of a plastics material, and a fixing element fixing said first and second beads together; a glazing panel held between said first and second beads; and a fire resisting intumescent member between the door or frame of the window and the glazing panel.
2. A glazed door or window according to claim 1 wherein a first fire resistant intumescent member is mounted on an edge of the glazing panel and a second fire resistant intumescent member is mounted on an inside edge of an aperture of the door or window frame which receives the glazing panel.
3. A glazed door or window according to claim 1 or 2 wherein fire resisting intumescent members are mounted on each edge of the glazing panel.
4. A glazed door or window according to any one of the preceding claims wherein fire resisting intumescent members are mounted on each edge of the aperture of the door or window which receives the glazing panel.
5. A glazed door or window according to any one of the preceding claims wherein the beads are pre-moulded plastic components.
6. A glazed door or window according to any one of the preceding claims wherein said beads have lugs on their loners sides, said fixing means being fixed to said lugs.
7. A method of making a glazed door or window comprising the steps of fixing together first and second plastics material beads on either side of a door or a window frame with a fixing element such that the beads receive and hold a part of a glazing panel between them and providing at least one fire resisting intumescent member between the door or frame of the window and the glazing panel.
8. A glazed door or window substantially as described herein with reference to the accompanying drawings.
9. A method of making a glazed door or window substantially as described herein with reference to the accompanying drawings.