WO2004065718A1

WO2004065718A1 - Fire resistant gutter plug

Info

Publication number: WO2004065718A1
Application number: PCT/AU2004/000063
Authority: WO
Inventors: Peter James Hurley
Original assignee: Peter James Hurley
Priority date: 2003-01-21
Filing date: 2004-01-20
Publication date: 2004-08-05
Also published as: AU2003900239A0

Abstract

A plug (60), formed of fire resistant compressible plastics material and shaped (Figs. 1-4) for insertion into a into a stormwater system (50-54) to thereby prevent drainage of fluid from said stormwater system. The plastics material is preferably a closed cell flexible foam such as polyethylene foam, EVA foam. Examples of suitable fire retardant additives for such materials include decabromodiphenyl oxide and antimony trioxide. A method (70) of manufacturing such a plug is also disclosed.

Description

FIRE RESISTANT GUTTER PLUG

Field of the Invention

The present invention relates to preventing buildings from fire ingress and, in particular, to apparatus that may be used for damming the guttering of homes and other buildings.

Background Much attention is today placed not only on preventing and extinguishing fires

within homes and other buildings, but also preventing the ingress of fire. Such is

particularly the case during periods of bushflre, as that term is known in Australia, or

forest fire, as the term is known in the United States.

During such periods, structures are highly susceptible to fire damage,

particularly through the effects of falling burning debris such as leaves, ash and cinders.

In many instances, such falling burning debris can travel substantial distances from the

fire front and impact upon buildings that might otherwise be thought to be in a safe area.

Typically, the ash and cinders can fall into storm water guttering that surrounds the

building roof whereupon they provide an ignition source. Further, any leaves or other vegetative matter contained within the guttering, as is often the case, can be set alight

thereby amplifying the danger to the structure. Fires commencing in guttering can soon

enter the roof space and rapidly spread throughout the entire structure.

It is traditional in Australia, as a preventative measure against such ingress during periods of bushfϊre, for householders to block or otherwise dam the storm water systems of their homes to thereby retain water in the guttering to prevent the above

described situation occurring and/or perpetuating. Typically, householders will fill cloth bags with sand or soil and insert the bag into the connection between the guttering and the downpipe. Some householders merely attempt to plug the downpipe using cloth or other material.

Such arrangements are often inadequate in two respects. Firstly, they are often ineffective in damming the downpipe to prevent drainage of water from the guttering. Secondly, such cloth, rags and other materials, should the water drain, become a combustible source which can further perpetuate the problem described above.

It has been proposed to provide a mechanical arrangement in the form of a releasable flap valve in order to close the downpipe thereby permitting the householder to fill the guttering system with water. Such an arrangement has been found to be unsuccessful in a number of aspects. Firstly, the arrangement is relatively expensive and thus can present a significant burden to the householder for purchase and installation. Secondly, the quality of the flap seal is one that can deteriorate over time if not properly maintained. In this regard, the bushfire problem noted above, is one that may only present itself as a problem, for example, one day in every year or two, and hence reliability of operation must be ensured for that one day.

It is an object of the present invention to substantially overcome, or at least ameliorate, problems of the existing arrangements of preventing fire ingress.

Summary of the Invention In accordance with one aspect of the present invention there is disclosed a plug, formed of fire resistant compressible plastics material and shaped for insertion into a into a stormwater system to thereby prevent drainage of fluid from said stormwater system.

Preferably, the material is sufficiently resilient to accommodate insertion into said stormwater system, and yet sufficiently malleable so that said material moulds into the shape of fixtures of said stormwater system into which said plug is inserted. In accordance with another aspect of the present invention, there is disclosed a

block of closed cell fire retardant flexible foam material. Preferably the block is shaped

for insertion into a stormwater system to thereby occlude the stormwater system.

In accordance with another aspect of the present invention, there is disclosed a

plug comprising a closed cell flexible foam incorporating fire retardant materials and

shaped for insertion into a stormwater system to thereby occlude the stormwater system.

method of manufacturing a plug, said method comprising the steps of:

mixing closed cell flexible foam material with a fire retardant additive;

sheeting the mixed material on a mill;

placing the sheeted material into flat moulds in a hydraulic press;

heating the hydraulic press to expand the materials to form blocks;

cooling and removing the blocks from the moulds; and

cutting the blocks to a size and shape adapted for insertion into a stormwater

outlet.

Other aspects of the invention are disclosed.

Brief Description of the Drawings

A number of embodiments of the present invention will now be described with reference to the drawings in which:

Figs. 1 to 4 illustrate exemplary shapes for fire resistant gutter plugs according the present disclosure;

Fig. 5 illustrates a traditional prior art comiection between guttering and downpipe;

Fig. 6 illustrates use of a gutter plug to dam the storm water system of Fig. 5; and Fig. 7 illustrates a manufacturing process for the gutter plug. Detailed Description including Best Mode

The present disclosure proposes that the bags and other cloth materials described above for obstructing the downpipes of stormwater systems in homes and other buildings, be replaced by a fire resistant plug shaped to reliably occlude the connection between guttering and downpipe.

Figs. 1 to 4 show various shapes and configurations of a fire resistant plug that may be used in traditional domestic arrangements in Australia. Traditional downpipe structures in Australia have two common sizes, those being 100 mm X 75 mm, and 100 mm x 50 mm. Some downpipe arrangements utilise 90 mm diameter PVC pipe connections. Other situations, particularly those encountered in industrial environments, use 100 mm x 100 mm arrangements.

The plugs of Figs. 1 to 4 are preferably manufactured from closed cell flexible foam, cut from a moulded block, to the requisite shape. Such foams are compressible and, as a consequence, the plug to be used is arranged to be "oversize" in comparison to the downpipe connection to be occluded. The plug material is preferably sufficiently resilient to withstand the stress of insertion in an emergency situation, and yet sufficiently malleable so that it will mould into the shape of the downpipe and other fixtures into which it is inserted. Fig. 1 shows a plug having a cross-section dimension of 110 mm x 110 mm, suitable for the 100 mm square downpipe referred to above. Fig. 2 shows an arrangement having a cross-sectional dimension of 85 mm x 110 mm which may be used for a 75 x 100 mm cross-section downpipe. Fig. 3 shows a 60 mm X 110 mm cross-section plug which may be used for downpipes having a 50 mm x 100 mm cross-section. Fig. 4 shows a cylindrical plug having a diameter of 100 mm, thereby being adapted to be used in 90 mm diameter PVC storm pipe. Each of the plugs shown in Figs. 1 to 4 preferably has a depth (or height) of 50 mm, which experiments by the present inventor have shown is sufficient to adequately engage and occlude the stormwater structures. Fig. 5 illustrates part of a traditional domestic stormwater arrangement in

Australia in which guttering 50 is arranged along the rim of the roof (not illustrated) of the building. A coupling 52 is provided which inserts through a hole formed in the base of the guttering 50 to provide a vertical outlet for stormwater from the guttering 50. A downpipe 54 is shaped to fit over the outlet 52 to channel water away from the guttering 50 to a terrestrial drainage pipe or channel. Typically, the outlet 52 is secured to the guttering 50 by means of pop-rivets and silicone sealants, with the guttering 54 being attached to the outlet 52 by means of pop rivets where necessary. For those applications utilising PVC stormwater fittings, PVC glues are often used to adhere and seal the stormwater fixtures. The glues are typically provided to adhere the complementary male and female coupling members of such fixtures.

As shown in Fig. 6, a plug 60 formed of closed cell flexible foam, and shaped to match the downpipe 54 and coupling 52, is inserted into the outlet 52 from above. Because the foam of the plug 60 is of a closed cell structure, such foam is compressible and engages the walls of the coupling 52 in a snug fashion. Once in position, the plug 60 attempts to expand to its original shape as a result of a "shape memory" function, known in the art of such foams. This results in an effective seal against the interior surfaces of the coupling 52 and/or downpipe 54. The displacement of the plug 60 is sufficient to at least provide a substantial seal, and arises from the type of material used in the construction of the plug 60. So as to assist in the prevention of fire ingress, once all downpipes in the guttering system of the building are occluded in the manner shown in Fig. 6, the guttering may be flooded with water, fire fighting foam, or other non-combustible liquid to achieve the desired effect. The closed cell flexible foam that may be used for the plug 60 may for example be manufactured from polyethylene foam, EVA foam, or a combination thereof. Other foams or plastics materials and structures, having a sufficient balance between resilience and malleability, as discussed above, may alternatively be used. For example, an elastomeric polyurethane or neoprene, with a fire retardant, can be used, but may be cost prohibitive. Fire resistant silicones may also be shaped to perform as the described plugs.

The closed cell flexible foam may be manufactured using the "bun" process, well known in the art. Preferably, the foams have a density of 30 - 100kg per cubic metre. As seen in Fig. 7, in a process 70, foam manufacturing materials 71, known in the art, are mixed in a low-sheer Banbury-type mixer 72. The mixed material 73is then formed into a sheet 74 on a mill 75, and placed in flat moulds 76 in a heated hydraulic press 77.

After partial reaction, blocks formed by the moulds expand from the press 77 and are placed in a larger mould 78 ("a foaming chamber") where further expansion takes place. The blocks are then cooled and removed from the moulds 78. Blocks up to 110mm thickness can be readily manufactured in this manner. Once removed from the moulds, the blocks can then be cut 79 to size to form the plugs 60.

According to the present disclosure, fire retardant additives 80 are provided to the foam materials 71 during the mixing stage. The fire retardant additives 80, as a consequence, form part of the foam structure and provide that the final manufactured plugs 60 will be resistant to ignition. The fire retardant additives may, for example, be decabromodiphenyl oxide, or antimony trioxide. Other suitable retardants may be used depending upon the type of material from which the plugs are being manufactured.

Whilst Figs. 1 to 4 show a variety of shapes and configurations that may be used, it is to be noted that one plug (having dimensions approximately 85 mm X 110 mm x 50 mm) can be produced to fit the two common sizes of rectangular outlet (ie. 100 mm X 75 mm, and 100 mm x 50 mm). This can be achieved using one face for one side and another face of the same plug for the other size. Alternatively, plugs can be stepped to accommodate a variety of shapes and sizes. Further, experiments by the present inventor indicate that a square plug (eg. Fig. 1, or another size) can fit into a round hole, such as that formed by PVC 90mm storm pipe, which might otherwise have associated therewith the plug of Fig. 4.

Typically, a household would have between 4 to 6 such plugs readily available for use during a fire emergency whereby the householder may insert the plugs into each downpipe outlet relatively quickly so as to thereafter fill the guttering. Because of the likelihood of deformity (ie. loss of shape "memory") and damage during removal after use, the present inventor cautions against repeated use of the plugs. Preferably, new plugs should be used for each fire emergency.

The foregoing describes only a number of embodiments of the present invention and modifications can be made thereto without departing from the scope of the present invention. For example, the dimensions of the plugs mentioned above are only exemplary for normal dimensions of Australian stormwater fixtures and the like. Further, dimensions will vary depending upon the compressibility of the material being used. Less compressible materials will necessitate blocks more closely sized to the fixtures into which they are to be inserted. In the context of this specification and claims, the word "comprising" means "including principally but not necessarily solely". Variations of the word "comprising" such as "comprise" and "comprises" have correspondingly varied meanings.

Claims

The claims defining the invention are as follows:

1. A plug, formed of fire resistant compressible plastics material and shaped for insertion into a into a stormwater system to thereby prevent drainage of fluid from said stormwater system.

2. A plug according to claim 1 wherein said material is sufficiently resilient to accommodate insertion into said stormwater system, and yet sufficiently malleable so that said material moulds into the shape of fixtures of said stormwater system into which said plug is inserted.

3. A plug according to claim 1 or 2 wherein said material is selected from the group consisting of:

(i) fire retardant polyethylene foam (ii) fire retardant EVA foam;

(iii) fire retardant elastomeric polyurethane;

(iv) fire retardant neoprene; and

(v) fire resistant silicone.

4. A block of closed cell fire retardant flexible foam material.

5. A block according to claim 4 wherein said block is shaped for insertion into a stormwater system to thereby occlude the stormwater system.

6. A plug comprising closed cell flexible foam incorporating fire retardant materials and shaped for insertion into a stormwater system to thereby occlude the stormwater system.

7. A plug according to claim 6 wherein said plug is shaped for insertion into a guttering outlet of the stormwater system to thereby prevent fluid escaping from the guttering through a downpipe thereof.

8. A plug according to claim 7 wherein said plug is sized and shaped for insertion into a guttering outlet sized according to one of the following sizes: i) lOOmm x 100mm; ii) 75mm x 100mm; iii) 50mm x 100mm; and iv) 90mm diameter.

9. The invention according to any one of claims 4 to 8 wherein said closed cell foam has a density of between 30 - 100kg per cubic metre.

10. The invention according to any one of claims 4 to 9 wherein said closed cell foam is one of polyethylene foam, EVA foam or a combination thereof.

11. The invention as claimed in any one of claims 4 to 10 wherein at least one of the decabromodiphenyl oxide and antimony trioxide are used to provide fire retardant properties to said closed cell foam.

12. A method of manufacturing a plug, said method comprising the steps of: mixing closed cell flexible foam material with a fire retardant additive; sheeting the mixed material on a mill; placing the sheeted material into flat moulds in a hydraulic press; heating the hydraulic press to expand the materials to form blocks; cooling and removing the blocks from the moulds; and cutting the blocks to a size and shape adapted for insertion into a stormwater outlet.

13. A method according to claim 12 wherein said foam material comprises one of polyethylene foam, EVA foam, or a combination thereof.

14. A method according to claim 12 or 13 wherein said fire retardant additive comprises at least one of decabromodiphenyl oxide and antimony trioxide.

15. A fire resistant plug substantially as described herein with reference to any one of Figs. 1 to 4 and Fig. 6 of the drawings.