IE42571B1

IE42571B1 - Fire barrier device

Info

Publication number: IE42571B1
Application number: IE838/76A
Authority: IE
Original assignee: Dufaylite Dev Ltd
Priority date: 1975-05-01
Filing date: 1976-04-21
Publication date: 1980-09-10
Also published as: IE42571L; FR2309331B1; AU1350176A; NZ180704A; IT1063214B; CH617485A5; ZA762466B; AU502017B2; CA1040826A; FR2309331A1

Abstract

The invention relates to a fire barrier device which comprises a grid of a structural cellular material. The material has cells which extend through the thickness direction of the grid from face to face thereof and have their walls defined by strip material. The walls are coated with an intumescent material. A surrounding metal frame is provided for the mounting of the grid, the frame defining an inwardly directed channel extending around the periphery of the grid and overlapping the peripheral regions of the faces of the grid. The peripheral regions nest in the channel but are free from attachment thereto so that the peripheral regions are free to move relative to the frame under fire conditions. An intumescent material lines the frame.

Description

The present invention relates to structural honeycomb materials, and other structural cellular materials in which cells extending through, the thickness direction of the material have their walls defined by strip material - e.g. eggbox structures.

When their cell walls are coated with an irttumescent material, which foams on heating to fill the cells, such materials haive proved effective in fire barrier devices. In their unheated state they offer only a low resistance to air10 flow, and are therefore used in the form of grids to provide automatic closing of ventilation apertures or ducting to resist the spread of fire.

In accordance with the present invention there is provided a fire barrier device which comprises a grid of a structural cellular material having cells which extend through the thickness direction of the grid from face to face thereof and have their walls defined by strip material, said walls being coated with an instumcscent material, a surrounding metal frame for the mounting of the grid, said frame defining an inwardly directed channel extending around the periphery of the grid and overlapping the peripheral regions of the faces of the grid, said peripheral regions nesting in said channel but being free from attachment thereto so that the peripheral regions are free to move relative to said frame under fire conditions, and an intumcscent material,lining the surfaces of said frame facing the grid 2 5 71 - 3 The fire resistance of the structure formed by foaming and carbonisation of the infcumescent material and carbonisation of the structural cellular material (usually formed of paper or cardboard) is improved by the metal frame in some applications compared with previous arrangements, the process of fire-break-through following a modified pattern. It appears that mechanical factors, as well as attrition of the structure, have been significant in leading to break-through with prior devices.

By making the metal frame discontinuous in the thickness direction of the grid, the rapid transfer of heat past the periphery of the grid by thermal conduction may be substantially eliminated. In a preferred arrangement, the metal frame is provided in the form of a pair of separate parts one of which has a flange overlapping the peripheral regions of one face of the grid and the other of which has a flange overlapping the peripheral regions of the other face of the grid, said pair of separate parts being held spaced apart out of mutual thermal communication by the grid.

The metal frame provided in the form of a pair of separate parts, or which is otherwise discontinuous, may be held together simply by a surrounding strip of sheet material adhesively secured thereto. This arrangement gives a satisfactory device for installation in a ventilation opening in a generally fireresistant partition wall, e.g. a wall formed of masonry. When cementing or otherwise securing the device in position, it is a simple matter to arrange that the parts of the frame are firmly located. Thus the strip of sheet material serves to provide a readily transported and installed device but is not relied upon after installation.

The intumescent material lining the metal frame modifies - 4 the pattern of fire-breakthrough obtained with the device, failure of the grid in the region of the frame being postponed. The lining is conveniently applied as a preformed strip material, e.g. an intumescent putty carried by a fabric backing. Alternatively, an intumescent composition in the form of a putty or mastic may be applied directly to the frame, e.g. using an adhesive gun or brush. Especially good results are obtained, if the intumescent material of the lining is positioned to lie over the peripheral regions of the faces of the grid within said channel. Having the intumescent material of the lining extend also across the base of the channel, and thus across the outer edge of the grid, is unnecessary in practice.

Further improvement is possible by sandwiching the grid between reinforcing members of metallic mesh material, and especially so when the reinforcing members are linked together through the cellular material such as by metal ties.

Advantageously such reinforcing members extend into the channel, and are secured by their peripheries thereto. The intumescent lining may extend between the grid and the parts of the reinforcing members which extend into the channel.

The following description of preferred embodiments of the invention, in which description reference is made to the accompanying diagrammatic drawings, is given in order to illustrate the invention.

In the drawings.· Figure 1 is a perspective of a part of a device according to the invention, Figure 2 shows a portion of a component part of the 30 device of Fig. 1, in isolation on an enlarged scale.

Figure 3 shows the device of Figs. 1 and 2 installed in an opening of a partition wall.

Figure 4 shows another device according to the invention, and Figures 5 and 6 are cross-sections taken along V---V VI---VI respectively.

In the device of Fig. 1, a metal frame is formed in two sections 81 and 82 dimensioned to fit around the edges of slab 3 of intumescent coated resinated paper honeycomb whilst leaving a peripheral gap between the mutually facing edges 83 and 84. This gap prevents the rapid transfer of heat by thermal conduction from one section to the other. The two sections are held in position by a band 85 of self-adhesive film shown partly peeled-away in Fig. 1 for simplicity of illustration.

The flange parts 06, 87, 80 of the frame sections are mitred to meet as shown for example at 88 in Fig. 1. The base parts of the vertical members of the frame sections are continued beyond the mitred edges of the flange parts and bent peripendicularly inwardly, e.g. at 90 in Fig. 2, to fit within the ends of the base parts of the horizontal frame members where they are secured by spot welding. Preferred positions of the spot welds beneath band 85 are shown at 92 in Fig. 1.

On each face of the honeycomb slab 3 is a reinforcing member of non-woven wire mesh 5 formed of a set of parallel horizontal wires and a set of vertical wires superposed thereon and welded thereto at each intersection. The edges of the reinforcing members extend to within the frame sections and are welded in position by spot welds 95. It is not 2571 - r> necessary for the pitch of welds 95 to be equal, to the mesh size of the reinforcing members. In Fig. 1 only alternate vertical wires are shown welded.

At their inner faces the flange parts of the frame 5 members are lined by strips 96 of fabric coated with an intumescent putty. These strips cover the edges of the wire mesh reinforcing members internally and have their inner faces in contact with the honeycomb slab.

The device of Fig. 1 is shown, in Fig. 3, fitted within 10 an opening 99 of a concrete partition wall 101 and cemented in position as at 102. After installation, the cementing holds the frame part of the device together, i.e. the band 85 is relied upon only until the device has been fitted.

When fire conditions occur on one side of wall 101, hot gases passing through the device causes the intumescent coating of the honeycomb slab to swell, carbonise and stop the gaseous flow. The peripheral regions of the slab are free to move sufficiently easily with the flange parts of the frame, in spite of interlocking of the carbonised strips 96 with the cells of the slab, to compensate for shrinkage effects.

The wire mesh reinforcing members prolong the integrity of the slab and thestrips 96 foam and carbonise, especially on the fire-side of the device, substantially increasing the time to eventual break-through.

A device as shown in Fig. 1 may be produced in any desired reasonable size depending upon its intended purpose. When the size exceeds, say, 15 cm overall iri the vortical or horizontal direction, it is advantageous to lit wire ties J03 as shown in Fig. 4. For large structure^ tho ties are prefer30 ably distributed as shown in Fig. 4, i.e. closer together at the top of the device than the bottom. In Figs. 4 to 6 parts - 7 corresponding to Figs. 1 and 2 are shown with primes.

Fig. 5 shows the manner in which the intumescent strip 961 lining the flange part 86' of the device of Fig. 3 laps over horizontal wire 51 of the mesh member 5 shown in Fig. 4.

Fig. 6 shows the manner in which one of the wire ties 103 of Fig. 4 links together horizontal wires 5' and 5 on opposite faces of the slab 3' of intumescent coated honeycomb.

Devices as herein described preferably employ structural honeycomb material as the structural cellular material. It is advantageous to install them with the double-thickness walls of the honeycomb cells running vertically. Suitable labelling may be provided to show the preferred orientation at the time of installation. As will be appreciated a preferred device for a rectangular opening dimensioned a x b is different from that preferred for a rectangular opening dimensioned b x a.

Claims

1. A fire barrier device which comprises a grid of a structural cellular material having cells which extend through the thickness direction of the grid from 5 face to face thereof and have their walls defined by strip material, said walls being coated with an intumescent materia], a surrounding metal frame for the mounting of the grid, said frame defining an inwardly directed channel extending around the periphery of the grid and overlapping 10 the peripheral regions of the faces of the grid, said peripheral regions nesting in said channel but being free from attachment thereto so that the peripheral regions are free to move relative to said frame under fire conditions, and an intumescent material lining the surfaces of 15 said frame facing the grid.

2. A device according to Claim 1 in which the metal frame is discontinuous in the thickness direction of the grid.

3. A device according to either of Claims 1 or 2 2o in which the metal frame is provided in the form of a pair of separate parts one of which has a flange overlapping the peripheral regions of one face of the grid and the other of which has a flange overlapping the peripheral regions of the other face of the grid, said pair of separate 25 parts being held spaced apart out of mutual thermal communication by the grid.

4. A device according to either of Claims 2 or 3 in which the metal frame is held together by a surrounding strip of sheet material adhesively secured thereto,

5. A device according to any one of Claims 1 to 4 in which the lining is a preformed strip material. 4 2 5 71 . 9 ..

6. A device according to any one of Claims 1 to 5 in which the intumescent material of the lining is positioned over said peripheral regions of said faces within said channel.

7. A device according to any one of Claims 1 to 6 in 5 which the grid is sandwiched between reinforcing members of metallic mesh material.

8. A device according to Claim 7 in which the reinforcing members extend into the channel.

9. A device according to Claim 8 in which the 10. Intrumescent lining extends between the grid and the parts of the reinforcing meiribers which extend into the channel.

10. Λ device according to any one of Claims 7 to ') in which the reinforcingmeiribers are secured together by ties which extend through cells of the grid.

11. 15 11. A fire barrier device substantially as hereinbefore described and illustrated by reference to the accompanying drawings.