AU648352B2 - Fire resistant sealing material - Google Patents

Description

AUSTRALIA

Patents Act 1952 COMPLETE SPECIFICATION FOR A STANDARD PATENT

(ORIGINAL)

Regulation 3.2 00 0 0 0 at o 0 1 0 .4 00 a 0 o 00, o oCl Name of Applicant: Fyreguard Pty. Ltd.

Actual Inventor(s): Jonathan Wexler and Graham Robert Porter 0 4 0 C0 0 4 06 0* Address for Service: Invention Title: DAVIES COLLISON, Patent Attorneys, 1 Little Collins Street, Melbourne, 3000.

Fire Resistant Sealing Material Details of Associated Provisional Application No: PK 3055 The following statement is a full description of this invention, including the best method of performing it known to me/us:

I

-2- FIRE RESISTANT SEALING MATERIAL i j iThe invention relates to a resiliently compressible fire resistant sealing ii material for sealing various types of openings in buildings where a fire resistant j construction is required.

Building regulations in developed countries require certain classes of building I to have specified levels of fire resistance which iF defined in terms of a Standard Method of Test usually produced by a domestic or international Standards Institution. In Australia, the relevant Standard is AS 1530 part 4 produced by the i 25 Australian Standards Association. In the United Kingdom, the relevant Standard is i BS 476 produced by the British Standards Institution, and there are similar publications produced by ISO for Europe and DI for Germany. These standards are similar in that they require a replica specimen of fire resistant construction to be incorporated in the wall or roof of an oil or gas fired test furnace and subjected to a standardised heating regime of temperature increase with time elapsed. The specimen is said to achieve a Fire Resistance Rating or Level of 30, 60, 120 or more minutes if after the specified period of heating, the specimen does not exhibit I -3collapse or a predetermined degree of weakening, does not develop holes which permit a defined passage of flames or hot gases and the temperature rise at the unexposed face of the specimen does not exceed specified limits.

There are two main types of building openings requiring fire sealing. The first type is known as a control joint and is the part of the building design which allows for thermal or flexural movement between adjacent major structural parts.

A vertical control joint within the length of a masonry wall may be from 10 to mm in width and extend for a full storey height, a horizontal control joint between a curtain wall and the edge of a floor slab may be up to 60 mm in width and be positioned around the building perimeter at each floor level and other types and sizes of control joints may occur at various junctions of building components. The second type of opening is that created to allow passage of services such as pipes, cable and ducts through the building. Such openings can vary greatly in size depending on the number and complexity of services to be accommodated.

In providing a means of fire sealing such oper-ngs it is desirable that in addition to having fire resistance, the material used is also flexible so as to permit thermal or other designed movement of adjacent building components.

The materials used in such applications have previously included ceramic, rockwool, or other mineral fibres in various felted forms; mastic compositions with acrylic, urethane or siliccne binders and mineral fillers; and heat intumescent products in various configurations including foam plastic resin carriers having a chemical base of hydrated alkali silicate, intercalated graphite, phosphate/carbohydrate, or other intumescent agents. All of these materials have limitations on their usefulness. For example, man made mineral fibre products are objectionable on environmental health grounds, intumescent products can be expensive and many have periods of fire resistance which are too short and mastics tend to be labour intensive in application and unsuitable for unsupported filling of gaps larger than 30 to 40 mm.

S f ,i -4- According to one aspect of the present invention there is provided a resiliently compressible fire resistant sealing material which comprises a plastic foam carrier impregnated with and/or incorporating an inorganic filler, a sintering agent and optionally other additive(s), such that when the sealing material is compressed and inserted into an opening, the sealing material substantially seals the opening and when the sealing material is heated to a temperature which decomposes the plastic foam constituents, a refractory residue remains which maintains substantially the original shape and integrity of the sealing material and provides an effective barrier to the passage of fire.

The plastic foam may be either of an open or closed cell construction. The open cell plastic foam is preferably a polyurethane resin and the closed cell plastic t foam is preferably a polyvinylchloride resin.

inorganic fillers are mineral fillers, such as, for example silicas, aluminas, aluminosilicates, alkaline earth silicates, clays, earths, metal oxides, carbonates, phosphates and sulphates or other mineral compounds capable of I prolonged exposure to temperatures exceeding 10000C without disruptive decomposition, phase change or shape alteration.

Examples of suitable sintering agents include oxides, phosphates, borates and alkali silicates which melt or soften so as to attach to and produce cohesion of the mineral filler particles to form a refractory residue at elevated temperatures.

The other additive(s) which may be impregnated or incorporated in the sealing material include intumescent agents, binding agents, thickeners, surfactants and biocides. Preferably, the intumescent agent is graphite.

The sealing material in accordance with a preferred embodiment of the present invention may be produced in any shape which will be suitable for sealing the opening desired to be fire sealed. For example, the sealing material may be produced in a long length strip form of circular, rectangular or other desired cross section for continuous gap filling; in short, blocklike pieces for collective packing into larger sized openings; or in customised shapes to suit specific applications. The sealing material may also be used to fire seal expansion joints between panels.

In a particularly preferred embodiment the sealing material is compressed and inserted into an opening in a building such that the sealing material wedges itself so as to form a seal between the boundaries of the opening and thereafter remains wedged during subsequent compression or expansion arising from thermal or other relative movements which may occur in the building.

The sealing material in accordance with a preferred embodiment of the present invention possesses the advantageous properties of lightness and resilient compressibility, allowing rapid installation within the confines of an opening and permanent wedging in the desired position without the need for supports, adhesives or other fixing means.

The sealing material may be coated on one or more of its surfaces so as to i provide a seal against passage of smoke through the structure. A suitable coating for this purpose may be provided by applying a further impregnating composition, such as, for example, the impregnating composition described in Example 3 to the surface of the sealing material at a rate of approximately 1.5 Kg/M 2 An intumescent agent, for example up to 4% of graphite powder, may also be impregnated or incorporated in the sealing material when it is used and as a fire sealant around vinyl insulated cables or other services having thermally degradable parts. The intumescent agent provides heat activated intumescent expansion of the plastic foam when placed in compression around the cable or service which assists to maintain the seal in place of the vinyl cable or thermally degradable part covering as it melts and shrinks away in the fire.

R L_ -6- On exposure to fire, the plastic foam carrier pyrolitically decomposes to a carboniferous residue which slowly burns away leaving a replicated, sintered structure of refractory inorganic filler particles which maintains the original shape and integrity of the sealing material and provides an effective barrier to the passage of fire and hot gases as defined in terms of standard fire resistance testing procedures. A fire resistant sealing material which functions at hot face temperatures up to and exceeding 1200 °C may be produced.

According to another aspect of the present invention there is provided a I 10 process for preparing the fire resistant sealing material described above which I comprises impregnating a plastic foam carrier with a mixture of an organic Sfiller, a sintering agent and optionally other additive(s).

SThe impregnating mixture may be introduced by any suitable method including compressing the plastic foam carrier to expel the air and then allowing the plastic foam carrier to recover its shape while immersed in the mixture. Ambient vacuum or pressure conditions may be used to assist this i method. Alternatively, infusion of the impregnating mixture can be achieved by pumping the mixture under pressure into the plastic foam carrier.

Preferably, the other additive is a binding agent which retains the inorganic filler and sintering agent in the plastic foam carrier.

The impregnation may be controlled by compressing the plastic foam carrier so as to remove the excess mixture. The residual sealing material obtained may then be set by any suitable known technique, such as, for example, drying, heating or irradiation.

According to a further aspect of the present invention there is provided a process for preparing a fire resistant sealing material as described above which comprises adding an inorganic filler, a sintering agent and optionally other additive(s) to a formulation of plastic foam.

ML-4 -7- According to a still further aspect of the present invention there is provided a process for preparing a fire resistant sealing material as described above which comprises adding an inorganic filler, sintering agent and optionally other additive(s) to a formulation of plastic foam.

Preferably, the formulation of plastic foam is a polyol/isocyanate/water foaming mixture.

Further according to the present invention there is provided a process for preparing a fire resistant sealing material as described above which comprises adding an inorganic filler, a sintering agent and optionally other additive(s) to a plastic foam carrier resin, a blowing agent and optionally a stabilizer and/or plasticiser to produce a mixture, and foaming the mixture to the desired shape.

The mixture may be shaped by continuous thermoplastic extrusion.

The invention will now be further described by way of example only.

These examples are not to be construed as limiting the invention in its broadest aspects.

The examples are based on the use of open cell polyurethane/polyether J foam manufactured to 30 Kg/M 3 density and treated by various impregnating compositions in aqueous suspensions to a finished dry weight of the order of 300 Kg/M 3 The rheological properties of the various compositions were adjusted by minor additions of thickeners, surfactants and biocide. The mineral fillers were all in fine powder form.

R -8- Example 1 Impregnating composition:- Weight% Acrylic latex emulsion 29 Nepheline syenite Wollastonite 18 Antimony oxide 11 Water 17 The resultant product in the form of 29 mm diameter round section foam was inserted into a 25 mm wide vertical gap within a 140 mm thick solid concrete block wall and when subjected to a standard fire resistance test, achieved a Fire Resistance rating of 4 hrs.

Example 2 Impregnating composition Weight% I Acrylic latex emulsion 28 Alumina hydrate Calcined clay Ammonium polyphosphate 8 Water 14 The resultant product in the form of three 50x20 mm rectangular section parallel strips was inserted into a 50 mm wide slot between 200 mm thick floor panels and when subjected to standard fire test conditions, achieved a fire resistance rating of 4 hours.

-9- Example 3 Impregnating composition Weight% Acrylic latex emulsion 24 Silica (quartzite) 33 Calcined clay 18 Borax Water 't I The resultant product in the form of a 20x20 mm square section strip was indicatively tested in a small scale furnace opening and maintained its shape and integrity for 2 hours at 1150 °C.

Ia 4 A 0 4 i i k I& r

Claims (14)

1. A resiliently compressible fire resistant sealing material which comprises a plastic foam carrier impregnated with and/or incorporating an inorganic filler, a sinteriig agent and optionally other additive(s), such that when the sealing material is compressed and inserted into an opening, the sealing material substantially seals the opening and when the sealing material is heated to a temperature which decomposes the plastic foam constituents, a refractory residue remains which maintains substantially the original shape and integrity of the sealing material and provides an effective barrier to the passage of fire.

2. A resiliently compressible fire resistant sealing material according to Claim 1, wherein the plastic foam is an open cell plastic foam. 00 4 3. A resiliently compressible fire resistant sealing material according to Claim 2, wherein the open cell plastic foam is a polyurethane resin.

4. A resiliently compressible fire resistant sealing material according to 00 4 20 Claim 1, wherein the plastic foam is a closed cell plastic foam. 4 4 I 5. A resiliently compressible fire resistant sealing material according to 0 i Claim 4, wherein the closed cell plastic foam is a polyvinylchloride resin. ,I 25 6. A resiliently compressible fire resistant sealing material according to any one of the preceding claims, wherein the inorganic filler is a mineral filler.

7. A resiliently compressible fire resistant sealing material according to Claim 6, wherein the mineral filler is selected from silica, alumina, aluminosilicate, alkaline earth silicate, clay, earth, metal oxide, carbonate, phosphate and sulphate. '1 11

8. A resiliently compressible fire resistant sealing material according to any one of the preceding claims, wherein the sintering agent is selected from oxides, phosphates, borates and alkali silicates.

9. A resiliently compressible fire resistant sealing material according to any one of the preceding claims, wherein the other additive(s) are selected from intumescent agents, binding agents, thickeners, surfactants and biocides. A resiliently compressible fire resistant sealing material according to Claim 9, wherein the intumescent agent is graphite.

11. A resiliently compressible fire resistant sealing material according to any one of the preceding claims, wherein the sealing material is compressed and inserted into an opening in a building such that the sealing material wedges itself so as to form a seal between the boundaries of the opening and thereafter remains wedged during subsequent compression or expansion arising from thermal or other relative movements which may occur in the building.

12. A process for preparing a resiliently compressible fire resistant sealing material according to Claim 2 or claims dependent thereon which comprises impregnating the plastic foam carrier with a mixture of an organic filler, a sintering agent and optionally other additive(s).

13. A process according to Claim 12, wherein the other additive is a binding agent which retains the inorganic filler and sintering agent in the plastic foam carrier.

14. A process according to Claim 12 or 13, wherein the amount of impregnation is controlled by compressing the plastic foam carrier so as to remove the excess mixture. s, A .to, ks it-;, I f -12- A process for preparing a resiliently compressible fire resistant sealing material according to Claim 2 or claims dependent thereon which comprises adding an inorganic filler, a sintering agent and optionally other additive(s) to a formulation of plastic foam.

16. A process for preparing a fire resistant sealing material according to Claim 4 or claims dependent thereon which comprises adding an inorganic filler, sintering agent and optionally other additive(s) to a formulation of plastic foam.

17. A process according to Claim 16, wherein the formulation of plastic foam is a polyol/isocyanate/water foaming mixture.

18. A process for preparing a resiliently compressible fire resistant sealing material according to Claim 4 or claims dependent thereon which comprises adding an inorganic filler, a sintering agent and optionally other additive(s) to a plastic foam resin, a blowing agent and optionally a stabilizer and/or a plasticiser to produce a mixture, and foaming the mixture to the desired shape.

19. A process according to Claim 18, wherein the mixture is shaped by continuous thermoplastic extrusion. Resiliently compressible fire resistant sealing materials or processes for their preparation, substantially as hereinbefore described with reference to the Examples. DATED this 21st day of January, 1994 Fyreguard Pty. Ltd. By Its Patent Attorneys DAVIES COLLISON -s^