Foil-shaped building material for sealing flat roofs

Description

[0001] The invention relates to a foil-shaped building material for sealing flat roofs, facades or similar building components, consisting of a permanently elastic top layer, in particular based on an ethylene propylene diene terpolymer (EPDM) and / or on a thermoplastic elastomer (TPE) as well as a back-laminated nonwoven reinforcement intermediate layer according to claim 1.

[0002] A roofing membrane for sealing flat and gently sloping roofs is known from DE 199 45 732 A1. The seal consists of a plastic sealing membrane and a self-adhesive layer. A soft, elastic intermediate layer is provided between the sealing membrane and the self-adhesive layer. This soft, elastic intermediate layer can be made of an elastomer or a nonwoven fabric with a foamed plastic layer. The nonwoven fabric, in turn, can consist of polyester fibers.

[0003] From a fire protection perspective, a layer of non-combustible material, such as glass fleece, can be placed between the intermediate layer and the self-adhesive layer. According to DE 199 45 732 A1, the glass fleece layer is bonded to the intermediate layer using a silicate adhesive.

[0004] German utility model DE 20 2011 004 818 U1 solves the problem of specifying a ridge and / or hip ventilation element that ensures permanent ventilation between the ridge ladder and the roof covering. Furthermore, the element is to be UV-stable and fire-resistant. For this purpose, the air-permeable area is made of any flexible, preferably soft and fire-resistant fibers. These can be glass fibers, stone fibers, carbon fibers, aramid fibers, or similar non-combustible fiber materials or fiber mixtures.

[0005] The fire-resistant membrane according to EP 0 172 898 B1 with vapor barrier for covering roof and wall surfaces is a laminated flame-retardant membrane made of a fiberglass fleece containing crystalline bound water. The fire-resistant membrane comprises an aluminum foil and plastic films laminated to both sides. A top plastic film, in turn, has a laminated fiberglass fleece.

[0006] The covering for roofs according to EP 0 591 691 B1 is based on a sealing membrane to which at least one fire protection layer with penetrations is assigned.

[0007] A layer of bitumen is arranged on both sides of the fire-resistant layer to embed the fire-resistant layer within the waterproofing membrane. The penetrations in the fire-resistant layer are filled with bitumen. The fire-resistant layer can be multi-layered and preferably consists of a layer of a non-combustible material and a second layer of a plastic, in particular a thermoplastic such as polypropylene, polyamide, or polyester.

[0008] In a preferred embodiment according to EP 0 591 691 B1, the fire-resistant layer is arranged directly below the outer surface of the top layer. This is intended to ensure that the fire-extinguishing property takes effect after a short time, because only small amounts of the softened bitumen of the outer top layer need to flow away through the opening in the fire-resistant layer before its fire-extinguishing effect becomes apparent.

[0009] Further foil-shaped building materials for sealing flat roofs, facades or similar building components are known from US 2017 / 210100 A1 and US 2018 / 119337 A1.

[0010] Based on the foregoing, the object of the invention is to provide a further developed film-shaped building material for covering flat roofs, based on an elastic top layer consisting in particular of EPDM and / or TPE, which on the one hand has a readily adhesive backing and on the other hand meets the requirements for demonstrating the fire resistance of roofs to external fire (so-called hard roofing). The aim is to achieve a membrane according to EN 13956 with integrated fire protection with the film-shaped building material to be created. The film-shaped building material should also be characterized in that fulfilling the fire protection requirements does not result in any deterioration of handling, aging behavior, or other mechanical properties.

[0011] The problem of the invention is solved by a foil-shaped building material according to the combination of features according to claim 1.

[0012] It is therefore assumed that a foil-shaped building material, known per se, is used for sealing flat roofs, facades or similar building components.

[0013] This foil-like building material consists of a permanently elastic top layer, primarily based on ethylene propylene diene monomer (EPDM) and / or thermoplastic elastomers (TPE). This material is known under the brand name "EVALASTIC" and is manufactured, offered, and distributed by alwitra GmbH & Co. Klaus Göbel / Trier.

[0014] The elastic top layer has a back lamination, which is described in detail below.

[0015] The lamination comprises an intermediate layer of glass fleece with a basis weight of essentially 25 g / m².

[0016] According to the invention, the reverse lamination has a polyester fleece with a carbon fiber content.

[0017] The glass fleece is designed as a partially pore-open intermediate layer.

[0018] The polyester fleece with carbon fiber content has a coating, at least at specific points, with a thermally activatable adhesive.

[0019] The intermediate layer of glass fleece and the layer of polyester fleece with carbon fiber content undergo a pressure- and temperature-controlled lamination process, bonding them to the back of the compound, specifically the EPDM and / or TPE material. The thermally activated adhesive melts due to the transferred heat and can penetrate the partially open fleece materials, creating a secure bond with the top layer.

[0020] The carbon fibers used preferably consist of a non-flammable, oxidized and thermally stabilized fiber mixture of polyacrylonitrile (PAN).

[0021] According to the invention, the carbon fiber content in the polyester fleece is in the range of essentially 30-70%.

[0022] The backing prevents the spread of flames into the substrate in case of fire.

[0023] The underside of the lamination can be bonded very well with commercially available roofing membrane adhesives.

[0024] The foil-shaped building material as described above is designed as a ready-to-install, one-step pressure-temperature lamination product.

[0025] The invention will be explained in more detail below with reference to an exemplary embodiment and to figures.

[0026] This shows: Fig. 1 a perspective view of the layer sequence produced in the calender process by means of hot lamination according to the first embodiment; Fig. 2 a layer sequence resulting from the production according to the second embodiment with an additional, self-adhesive backing layer, which is covered with a peelable release film; and Fig. 3 a schematic representation of a calender lamination process for the production of the film-shaped building material according to the invention.

[0027] Extensive investigations and fire tests have shown that a glass fleece lining alone, even in a higher grammage than usual, is not sufficient to meet the fire protection requirements, in particular the standard CEN / TS 1187.

[0028] According to the invention, to reduce the fire load, a polyester fleece with proportionate carbon fibers was used as a back lamination in the exemplary embodiment.

[0029] It has been shown that, according to the exemplary embodiment, a structure consisting of a backing with an intermediate layer of glass fleece weighing less than 25 g / m² and a polyester fleece with 30% carbon fiber content meets the fire protection requirements. Furthermore, the backing is adhesive, so there are no disadvantages in this respect either.

[0030] During the laminating process, which takes place under a pressure-temperature regime, it is important to ensure that a maximum contact pressure is maintained so that no damage to the nonwoven fabric occurs, in particular no damage to the glass nonwoven fabric.

[0031] Comparative tests were conducted to examine the fire behavior of a roofing membrane that consists primarily of an EPDM and / or TPE top layer and whose backing comprises a glass fleece of varying grammage as well as a polyester fleece or a mixed fleece.

[0032] None of the options in question met the fire protection requirements.

[0033] In contrast, tests based on a lamination with an intermediate layer of glass fleece and polyester fleece containing carbon fibers yielded excellent results. The investigations revealed that the non-combustible carbon fiber fleece prevents the spread of flames into the substrate, primarily by stabilizing the fire within the membrane itself. Thus, in the fire tests conducted, the carbon fiber-reinforced fleeces beneath the fire basket formed a strong bond with the 25 g / m² glass fleece. This ensures that the fire does not spread to the reverse side.

[0034] However, constructing a carbon fiber fleece without glass fleece is critical, as in such a case the fire basket sinks comparatively deeper into the insulation, especially made of EPS rigid foam, and a fire channel forms to the side unusually quickly.

[0035] According to the full tests carried out according to CEN / TS 1187, the installation of the building material according to the invention is possible directly on unlaminated EPS rigid foam in conjunction with different supporting shells such as wood, trapezoidal sheet metal, aerated concrete, concrete and also with direct installation on wood.

[0036] The requirements regarding proof of fire resistance of roofs from external fire (so-called hard roofs) are met. Furthermore, it has been experimentally determined that the backing material exhibits improved bonding properties compared to pure polyester fleece.

[0037] A method for producing a foil-shaped building material, as described above, uses a calender hot lamination process, in which a top layer is bonded to at least one back layer under pressure via at least one intermediate layer.

[0038] The top layer is a thermoplastic polymer layer 1.1 as described in the Figures 1 and 2 depicted.

[0039] The intermediate layer 1.2 is designed as an intermediate layer made of an open glass fleece.

[0040] The back layer is a polyester fleece with a carbon fiber content of 1.3.

[0041] This layer 1.3 is coated with an adhesion-promoting, thermoplastic polymer powder 1.6 prior to the hot lamination process, whereby the polymer powder 1.6 is melted during the hot lamination process and pressed under pressure through the open or semi-open structure of the glass fleece 1.2 and thermally fixed to the back of the cover layer 1.1.

[0042] Although in the Figures 1 and 2 Not shown, the top layer 1.1 may have reinforcement in the form of a mat or fabric.

[0043] According to the invention, it is possible in a preliminary manufacturing step to produce a composite of polyester fleece 1.3 and glass fleece 1.2 with molten thermoplastic polymer powder 1.6 and then to supply this product as a semi-finished product for hot lamination.

[0044] In one embodiment of the invention, the pre-coating with plastic powder 1.6 is carried out using a scattering method.

[0045] The back fleece 1.3 can be provided on its free side with a self-adhesive layer 1.4, which in turn is provided with a removable silicone release film 1.5.

[0046] In the representation according to Figure 3 The masquerading process is symbolized.

[0047] The outermost, weather-resistant layer, which is used in the field, is made of a permanently elastic thermoplastic polymer layer, which is in Figure 3 to be supplied to the roller arrangement shown in area E.

[0048] In the laminating process, the adhesion-promoting powder granules 1.6 are melted onto the supplied polyester fleece 3.2 by the temperature of the molten plastic at the calender roller 3.1 and fed under pressure to the adjacent, preferably rubberized, pressure roller 3.3. The molten powder is then pressed through the semi-open or open structure of the tensioned glass fleece layer 3.4 onto the back of the plastic top layer 3.6 and thermally fixed there.

[0049] After the cooling process, the thermoplastic polymer powder forms an adhesion-promoting layer between the polyester fleece, the glass fleece as a fire protection layer and the actual plastic top layer.

[0050] The process-determining parameters are defined as the temperature of the plastic melt at the calender, the melting temperature and the chemical-physical structure of the plastic powder on the polyester fleece, the structure, thickness and properties of the fire protection layer and its binder materials, the contact pressure of the laminating roller and the lead-in stresses of the supplied fire protection and polyester fleece sheets.

[0051] The process continues to involve the process of pulling in area A according to Figure 3 The calender roll 3.1 and the subsequent web guidance are of essential importance. Key parameters here are the web tension, take-off angle and temperature of the calender roll, as well as the wrap angle of the web on the subsequent transport rolls indicated in the figure, along with their adjustable torques that act on the guided web.

[0052] As previously explained, the top layer is designed as a permanently elastic, thermoplastic polymer layer. An open-cell glass fleece with a basis weight of at least 25 g / m² is preferably used as an intermediate layer. The glass fleece provides an integrated fire protection layer.

[0053] The polyester fleece applied to the back, with a basis weight of, for example, 80 to 250 g / m², can, as already explained, be provided with a self-adhesive layer. This self-adhesive layer can consist of a PSA, butyl, or acrylate adhesive.

[0054] Typically, a glass fleece in the composite between plastic compound and polyester fleece acts as an adhesion-reducing separating layer due to its physical and chemical structure.

[0055] This disadvantage is overcome according to the invention by pre-coating the polyester fleece to be laminated with an adhesion-promoting, thermoplastic polymer powder. This makes it possible to achieve a secure, force-fit bond between the polyester fleece, glass fleece, and polymer compound.

[0056] Polyester nonwoven fabric can be a thermally and / or chemically bonded and / or bonded using needles, water jets and / or air jets, which contains filament and staple fibers.

[0057] To further reduce the fire load, a mixture of carbon and polyester fibers is advantageous.

[0058] The glass fleece is designed as a semi-open structure and a polyvinyl alcohol, polyvinyl acetate or formaldehyde binder, or as an open polyester nonwoven or woven fabric, or as a combination of glass fleece and nonwoven / woven fabric.

[0059] The structure of the glass fleece, with parameters such as open areas and overall strength, is optimized for the penetration of the hot melt adhesive powder during the lamination process and is influenced by the desired fire protection effect.

[0060] A closed fabric, for example polyamide, with a hot melt adhesive coating on both sides can also be used as an additional fire protection layer.

[0061] Thermoplastic polyolefins, such as copolyesters, polyamides, ethylene vinyl acetates, HDPE, LDPE, or PP, are used as adhesion-promoting plastic powders. The melting range is tailored to the polarity and temperature of the top layer and is generally between 60 and 160°C.

[0062] The pre-coating of the polyester fleece with the adhesion-promoting, thermoplastic polymer powder is carried out, for example, using the powder spreading method.

[0063] With the help of the Figures 4 to 6 Further various process techniques for the production of the building material according to the invention will be explained.

[0064] The Figure 4 This shows the execution of the procedure using a doubling calender.

[0065] Here, at the doubling calender, the reverse side of the plastic sheet 4.3 and the adhesion-promoting powder granules on the supplied polyester fleece 4.4 are melted by the application of temperature through preheating by preheating rollers 4.1 and by the arrangement of infrared emitter fields 4.2 and, under the pressure of a pressure belt 4.5, in particular a rubberized one, are pressed through the semi-open structure of the fire protection layer 4.6, which is supplied under tension, onto the reverse side of the plastic sheet 4.3 and thermally fixed.

[0066] In the representation according to Figure 5A 2-roll calender process is used. Here, too, the reverse side of the plastic sheet 5.2 and the adhesion-promoting powder particles on the supplied polyester fleece 5.3 are melted by preheating with infrared emitters 5.1 and, under the pressure of a 2-roll calender, consisting of a cooled steel roller 5.4 and a coated pressure roller 5.5, are pressed through the semi-open structure of the tensioned fire protection layer 5.6 onto the reverse side of the melted plastic sheet 6.5 and thermally fixed.

[0067] Figure 6 shows an exemplary process using a belt press.

[0068] In a belt press, continuous heating of the individual layers is achieved by applying temperature with the help of a heating drum 6.1 and, if necessary, supported by additional infrared emitters and under pressure by a circulating metal belt 6.2.

[0069] Under pressure and temperature, the adhesion-promoting powder granules are melted onto the supplied polyester fleece 6.3. The semi-open structure of the fire-resistant layer 6.4 causes it to be pressed against the back of the melted plastic sheet 6.5 and thermally fixed. The infeed to the belt press, the direction of rotation of the belt press, and the outfeed at the belt press are symbolized by arrows.

Claims

1. A sheet-like building material for sealing flat roofs, facades or similar parts of buildings, consisting of a permanently elastic top layer (1.1) based on an ethylene-propylene-diene terpolymer (EPDM) and / or based on a thermoplastic elastomer (TPE) and an intermediate layer (1.2), laminated on the back, made of a glass fibre nonwoven fabric, characterised in that the lamination on the back has a polyester nonwoven fabric with a carbon fibre content, wherein the carbon fibre content in the polyester nonwoven fabric lies in the range between substantially 30-70%, and the polyester nonwoven fabric with the carbon fibre content has an at least selective coating with a thermally activatable adhesive (1.6), wherein the intermediate layer (1.2) consists of an open glass fibre nonwoven fabric with a grammage of at least 25 g / m2, wherein the glass fibre nonwoven fabric is configured as an intermediate layer which is partially open on the pore side and this makes possible penetration by the thermally activatable adhesive in the melted condition in order to form a safe bond with the top layer.

2. The sheet-like building material according to Claim 1, characterised in that the carbon fibres consist of non-flammable, oxidised and thermally stabilised fibres made of polyacrylonitrile (PAN).

3. The sheet-like building material according to any one of the preceding claims, characterised in that, in the event of a fire, the lamination on the back prevents a propagation of flames spreading into the installation substrate.

4. The sheet-like building material according to any one of the preceding claims, characterised in that the underside of the lamination can be glued.

5. The sheet-like building material according to any one of the preceding claims, characterised in that it is configured as a ready-to-install, one-step pressure-temperature laminating product.