Patent Publication Number: US-2018031150-A1

Title: Firestop collar

Description:
The invention relates to a firestop collar for sealing of openings, especially of line penetrations, that pass through walls or ceilings, with a frame and a block of optionally intumescent material disposed therein. 
     Firestop collars, which are capable of sealing line penetrations of non-fire-resistant pipes or cables in ceilings or walls in the event of fire, in order to prevent the spread of fire and smoke in buildings, are known in the most diverse configurations. The firestop collars usually contain an intumescent material, which is disposed around the lines, and a frame of sheet metal, which jackets the intumescent material and serves to fasten the intumescent material to walls or ceilings. The firestop collars are usually attached around the penetrating lines upstream from the openings, since mounting is simpler there. 
     As an example, DE 10 2011 089 531 A1 discloses a firestop collar of the type mentioned in the introduction, consisting of a block of intumescent material and a frame surrounding this. 
     EP 2 455 135 A2 teaches a fire-protection element which, in addition to the intumescent material, has a reinforcing inlay, which stabilizes the ash layer formed in the event of fire. 
     A disadvantage of the known firestop collars is that they are suitable only for certain opening cross sections. This leads to the situation that either a finite number of standard sizes must be used, which sizes are frequently not optimally configured, or that an individually configured firestop collar must be specially made for each opening. 
     The object of the invention is to provide a firestop collar that can be adapted easily to opening cross sections of various sizes and easily combined with further firestop collars. 
     To solve this object, it is provided, in a firestop collar of the type mentioned in the introduction, that the block of optionally intumescent material is a regular polyhedron, for example a cuboid. This has the advantage that either a plurality of firestop collars or a plurality of blocks can be disposed next to one another, thus creating greater flexibility for sealing of larger openings. 
     In a preferred embodiment, the block of the firestop collar is a molded part and is inserted in one or more pieces into the frame and is built-in together therewith. This has the advantage that the number of blocks used for the firestop collar can be matched easily to the opening to be sealed. The reduction of the molded parts to a few modular common parts offers further advantages beyond this from the logistical and economic perspective. 
     In an alternative embodiment, the firestop collar is formed by first mounting the frame and then introducing the block of optionally intumescent material by means of a foam material with intumescent properties, wherein the foam material is a foamable material, such as an in-situ foam, for example, that is introduced into the frame and then fills it by foaming up. The advantage of this approach is that only the foam material instead of molded parts has to be kept in readiness, and an individually adapted block of optionally intumescent material is obtained automatically by foaming the frame in place. 
     In a preferred embodiment, an intumescent inlay is disposed between the block and the frame. 
     In the event of fire, the heat causes the intumescent inlay to be activated and to expand. Preferably the block consists of intumescent material, so that, by using, for the intumescent inlay and the block of optionally intumescent material, various intumescent materials with different properties, for example with respect to activation temperature and expansion behavior, the pressure variations can be adapted in such a way over the duration of the fire that the stability of the resulting ash crust of the intumescent block is improved. These features make it possible to cover much larger opening cross sections with this firestop collar, without causing the stability problems known from the prior art to occur. In particular, opening sizes ranging from 100 mm×300 mm up to 150 mm×750 mm can be sealed with the inventive firestop collar. 
     The frame of the firestop collar may have a plurality of side portions that surround the block of optionally intumescent material on its side rims, as well as a plurality of front portions extending perpendicularly relative to the side portions. This configuration of the frame ensures that the block of optionally intumescent material is securely fastened and in the event of fire expands directionally, in order to bring its fire-protection properties optimally into effect. 
     The height of the block of optionally intumescent material is preferably slightly greater than the height of the side portions. Hereby the firestop collar has a projecting length of optionally intumescent material on the wall side, and so this is pressed with preload against the surface of the wall or ceiling during mounting. 
     Preferably, this projecting length is 2 mm to 6 mm, which leads to an optimum contact pressure effect. 
     In a preferred embodiment, the intumescent inner liner extends along at least one of the side portions. Alternatively, the intumescent inlay may also extend additionally, even along the front portion allocated to the side portion. Due to this configuration, the active forces that the intumescent inlay exerts on the block of optionally intumescent material are advantageously directed, namely toward the interior and toward the wall or ceiling. 
     In one embodiment, the block consists of a foamable material. Hereby sound absorption is also ensured in addition to imperviousness to smoke gas. In one preferred embodiment, the block consists of a foamable binding agent, which contains at least one ash-forming and optionally intumescent mixture. This binding agent acts as a composite-forming carrier for the ash-forming and optionally intumescent mixture. Preferably, the mixture is distributed homogeneously in the binding agent. The composite-forming carrier is preferably chosen from the group consisting of polyurethanes, phenol resins, polystyrenes, polyolefins such as polyethylene and/or polybutylene, melamine resins, melamine resin foams, synthetic or natural rubber, cellulose, elastomers and mixtures thereof, wherein polyurethanes are preferred. 
     The ash-forming and optionally intumescent mixture comprises the fire-protection additives that are common and known to the person skilled in the art and that foam up in the event of fire, i.e. under the effect of heat, and while doing so form a foam, such as an intumescent material on the basis of an acid-forming agent, a carbon-producing compound and a blowing agent, that prevents the spread of flames. Preferably the intumescent material comprises, as acid-forming agent, a salt or an ester of an inorganic, nonvolatile acid chosen from among sulfuric acid, phosphoric acid and boric acid, as carbon-producing compound, a polyhydroxy compound and/or a thermoplastic or thermosetting polymeric resin binding agent, and, as blowing agent, a chloroparaffin, melamine, a melamine compound, especially melamine cyanurate, melamine phosphate, melamine polyphosphate, tris(hydroxyethyl)cyanurate, cyanamide, dicyanamide, dicyandiamide, biguanidine and/or a guanidine salt, especially guanidine phosphate or guanidine sulfate. 
     The composite-forming carrier may further contain, as ablative additive, an inorganic compound, which has incorporated water, e.g. as water of crystallization, and does not dry out at temperatures up to 100° C. but releases the water starting at 120° C. in the event of fire and thereby is able to cool temperature-conducting parts, wherein the said compound is preferably an inorganic hydroxide or hydrate, especially aluminum hydroxide, aluminum oxide hydrates or partly hydrated aluminum hydroxides, which release water at fire temperature or when exposed to flames. Other inorganic hydroxides or hydrates that release water when exposed to flames may also be considered, however, such as are described in EP 0 274 068 A2. 
     Such compounds, which may be used as the mixture in the inventive fire-protection inlay, are known to the person skilled in the art and, for example, are disclosed in the following publications, to which reference is expressly made herewith: DE 30 25 309 A1, DE 30 41 731 A1, DE 33 02 416 A1, DE 34 11 327 A1, EP 0 043 952 B1, EP 0 051 106 B1, EP 0 061 024 B1, EP 0 116 846 B1, EP 0 158 165 B1, EP 0 274 068 A2, EP 1 347 549 A1, EP 1 641 895 B1 and DE 196 53 503 A1. 
     The molded block is produced by foam molding, such as reaction injection molding (RIM) with foam, corresponding to DE 3917518, e.g. with Fomox® fire-protection foam or with HILTI CP 65GN, a construction material that forms an insulating layer. Materials that can be used for inventive purposes are known from EP 0061024 A1, EP 0051106 A1, EP 0043952 A1, EP 0158165 A1, EP 0116846 A1 and U.S. Pat. No. 3,396,129 A as well as EP 1347549 A1. Preferably, the molded block consists of an intumescent-capable polyurethane foam, such as is known from EP 0061024 A1, DE 3025309 A1, DE 3041731 A1, DE 3302416 A and DE 3411 327 A1. 
     The block of optionally intumescent material is preferably provided with a reinforcing inlay. This reinforcing inlay serves for stabilization of the intumescent crust formed in the event of fire, and it helps to prevent parts of this from falling out of the firestop collar. For this purpose, it is advantageous to position the reinforcing inlay in the surface of the block of optionally intumescent material, in order to stabilize the outer faces. 
     The reinforcing inlay is preferably formed by a mat, a mesh or a fabric. Such a construction offers good penetration of the block of optionally intumescent material, and the reinforcing inlay retains its stabilizing properties even if structural damage is sporadically present. 
     In a preferred embodiment, the reinforcing inlay consists of a temperature-resistant material, for example metal, glass fibers, basalt fibers, carbon fibers or ceramic fibers. A hybrid structure comprising several materials in the reinforcing inlay is also possible. The higher temperature resistance compared with the intumescent material is advantageous, since the reinforcing inlay is not impaired by the temperature that activates the intumescent material and so is able to exert its stabilizing function in this way. 
     In a further preferred embodiment, the reinforcing inlay consists of expanded metal. This is advantageous with respect to the stabilizing effect. 
     The firestop collar is preferably fastened by means of a plurality of fastening brackets on its side portions. These permit secure fastening of the firestop collar to walls and ceilings and, for example, they can be joined to the side portions via plug-type means. For fastening, the firestop collar may be placed directly on the wall. An additional frame is not necessary, nor is double framing. It is also possible to mount the firestop collar directly over an already present firewall, so that it acts as a repair wall. 
     In a preferred embodiment, the frame of the firestop collar is of modular construction. This means in particular that this is constructed from a few common parts and can be configured in diverse ways. This has the advantage that the frame can be adapted individually in place to the opening cross section and that efficient use of material is possible. In addition, a reduction of the parts from which the frame is constructed to a few modular common parts offers further advantages beyond this from the logistical and economic perspective. 
     Preferably, the frame of the firestop collar consists of a plurality of individual parts, which are joined to one another by a plug-type connector. Thus, when the frame is dismantled into individual parts, it may be transported in compact form and mounted simply by the plug-type connectors. 
     In a further embodiment, the frame of the firestop collar is formed from one continuous strip, which is cut to the desired length and the end of which is joined to its beginning. In this way, the frame can be adapted individually to various opening cross sections. 
    
    
     
       Further advantages and features will become obvious from the description hereinafter in conjunction with the attached drawings, wherein: 
         FIG. 1  shows a sectional view of a first embodiment of the inventive firestop collar, which has been attached upstream from a line penetration, 
         FIG. 2  shows a sectional view of a preferred embodiment of the inventive firestop collar, which has been attached upstream from a line penetration, 
         FIG. 3 a    shows, in a top view in the direction of the face bearing on the wall, a firestop collar with a frame of modular construction according to a second embodiment of the invention, 
         FIG. 3 b    shows a first side view, 
         FIG. 3 c    shows a second side view, and 
         FIG. 3 d    shows a perspective view of the second embodiment of the inventive firestop collar. 
     
    
    
       FIG. 1  shows a first embodiment of a firestop collar  10 , which is attached at an opening, e.g. in a wall  11 , upstream from a line penetration  12  of a line  14 . The firestop collar contains a frame  16  as well as a block  20  of optionally intumescent material located therein, and is joined to wall  11  via fastening brackets  26 . As an example, line  14  is a water pipe of plastic or contains one or more cables. 
     Frame  16  has a plurality of side portions  17 , which surround block  20  on its side rims  18  and relative to which a plurality of front portions  19  extends perpendicularly. On the side facing away from block  20 , a plurality of fastening brackets  26  is provided on these side portions  17 . 
     Block  20  has a reinforcing inlay  24 , which preferably is integrated into the outer surface of block  20 . The reinforcing inlay  24  may be formed by a mat, a mesh or a fabric. 
     Preferably, reinforcing inlay  24  consists of particularly temperature-resistant material, such as metal, glass fibers, basalt fibers, carbon fibers, ceramic fibers or a hybrid material, for example. 
     Alternatively, expanded metal may be used for reinforcing inlay  24 . 
     Block  20  may be provided as a molded part, for example in the form of a cuboid. In this case, block  20  is preferably slightly larger than frame  16  surrounding it, in order to guarantee secure seating of block  20  in frame  16 . In particular, block  20  is 2 mm to 6 mm higher than side portions  17 , and, by virtue of this projecting length toward the wall side, it may be mounted in such a way on wall  11  that the intumescent material is pressed with preload against the surface. 
     Alternatively, block  20  may also be formed by a foam material introduced into frame  16 . For this purpose, frame  16  is first fastened upstream from line penetration  12  and then the space surrounded by frame  16  is filled by injection molding with an intumescent foam material. Depending on configuration, reinforcing inlay  24  may be introduced at various points in time. 
     Fastening brackets  26 , which consist of angled sheet-metal, for example, are joined on the outside of frame  16  to side portions  17 . As an example, this joint may be made in the form of a plug-type connector by means of brackets or else via additional fastening elements, such as screws or rivets. 
     By means of fasteners  28 , firestop collar  10  can be fastened to wall  11  via fastening brackets  26  attached to side portions  17 . For example, by the fact that screws are used as fasteners  28 , the preload of firestop collar  10  can be adjusted by tightening these. 
       FIG. 2  shows a preferred embodiment of the firestop collar, which contains a frame  16 , a block  20  of optionally intumescent material located therein and an intumescent inlay disposed therebetween, and is joined to wall  11  via fastening brackets  26 . Intumescent inlay  22  is fixed between frame  16  and block  20  and extends along side portions  17  and the respective front portions  19 . If the block in this embodiment is formed by foam material introduced into frame  16 , then for this purpose frame  16  including the intumescent inlay is first fastened upstream from line penetration  12  and then the space surrounded by frame  16  is filled by injection molding with an intumescent foam material. 
       FIGS. 2 a  to 2 d    show a second embodiment of a firestop collar  10  in various views, wherein frame  16  is of modular construction and preferably consists of a plurality of individual parts  30 , which are joined to one another by plug-type connectors  32 . 
     In the illustrated variant, firestop collar  10  consists of three rectangular blocks  20  of optionally intumescent material and one frame  16  of two L-shaped individual parts  30 . These L-shaped individual parts  30  may also be straight strips, which in particular were bent in place at right angles, in order to form a frame  16  adapted to the opening cross section. 
     In one embodiment (not illustrated), frame  16  is formed from one continuous strip, which is cut to the desired length and joined at its ends. 
     In one embodiment (not illustrated), firestop collar  10  consists of at least two parts, wherein only one part, especially one half, may also be used as a fully effective firestop collar  10 . 
     In particular, firestop collar  10  is dimensioned such that fire-resistance class El  120  is achieved even for walls with a thickness of 100 mm. 
     In the marketplace, moreover, it is possible to offer firestop collar  10  not only as a complete set but also as individual parts thereof. In particular, frame  16  and block  20  of optionally intumescent material may be sold individually.