Roofing underlay, particularly for using as roof cladding underlay and/or roof lining membrane

Abstract

The invention relates to a roofing underlay (1), especially one intended for use as roof cladding underlay and/or roof lining membrane, having at least one outer nonwoven layer (2), at least one inner nonwoven layer (3) and at least one microporous membrane layer (4) based on at least one polyolefin plastic, wherein the membrane layer (4) is arranged between the outer nonwoven layer (2) and the inner nonwoven layer. According to the invention, it is provided that at least one further microporous membrane layer (5) based on a polyolefin plastic is provided between the outer nonwoven layer (2) and the inner nonwoven layer and the further membrane layer (5) is separated from the membrane layer (4) by a separating layer (6), wherein the separating layer (6) is water-permeable and/or embodied as a structure made of fibers, especially nonwoven.

Claims

1. A roofing underlay comprising: at least one outer nonwoven layer, at least one inner nonwoven layer, and at least one microporous membrane layer that includes at least one polyolefin plastic, wherein the microporous membrane layer is arranged between the outer nonwoven layer and the inner nonwoven layer, wherein at least one additional microporous membrane layer that includes polyolefin plastic is provided between the outer nonwoven layer and the inner nonwoven layer, and in that the additional microporous membrane layer is separated from the microporous membrane layer by a nonwoven separating layer, wherein the nonwoven separating layer is water-permeable, wherein the roofing underlay is water-tight and water vapor-permeable.

2. The roofing underlay according to claim 1, wherein a plurality of additional membrane layers are provided, wherein adjacent microporous membrane layers are separated from each other by another separating layer.

3. The roofing underlay according to claim 1, wherein one or more of the microporous membrane layer and the at least one additional microporous membrane layer comprises a material based on polypropylene (PP) and/or polyethylene (PE).

4. The roofing underlay according to claim 1, wherein one or more of the microporous membrane layer and the at least one additional microporous membrane layer has a thickness in the range of 20 to 200 μm.

5. The roofing underlay according to claim 1, wherein the at least one microporous membrane layer has a grammage between 15 and 150 g/m.sup.2.

6. The roofing underlay according to claim 1, wherein the thickness of the at least on microporous membrane layer facing toward the outer nonwoven layer is between 50% and 200% greater than the thickness of the at least one additional microporous membrane layer facing toward the inner nonwoven layer.

7. The roofing underlay according to claim 1, wherein the thickness of the at leak one additional microporous membrane layer facing toward the inner nonwoven layer is greater by between 50% and 200% than the thickness of the at least one microporous membrane layer facing toward the outer nonwoven layer.

8. The roofing underlay according to claim 1, wherein the outer nonwoven layer has a grammage between 20 and 200 g/m.sup.2.

9. The roofing underlay according to claim 1, wherein the inner nonwoven layer has a grammage between 1 and 150 g/m.sup.2.

10. The roofing underlay according to claim 1, wherein the separating layer is a nonwoven layer, a perforated foam, an open-pore foam, a foam layer, a scrim, a textile, or an adhesive applied in a filamentous structure, a fibrous structure, and/or in a grid pattern, and the separating layer has a grammage between 1 and 150 g/m.sup.2.

11. The roofing underlay according to claim 1, wherein the roofing underlay is selectively permeable or water-tight, with a water column between 0.8 and 40 m.

12. The roofing underlay according to claim 1, wherein a water vapor diffusion-equivalent air layer thickness of the roofing underlay is between 0.02 and 0.5 m.

13. The roofing underlay according to claim 1, wherein one or more of the at least one outer nonwoven layer, the at least one inner nonwoven layer and the separating layer includes a plastic material, a thermoplastic material, polyester (PES), polyethylene (PE), polypropylene (PP) and/or polyethylene terephthalate (PET).

14. The roofing underlay according to claim 1, wherein adjacent membrane layers are joined to the inner or outer nonwoven layer by ultrasound welding, punctual spot welds, bonding, punctual partial bonding, and/or by hot calendering.

15. The roofing underlay according to claim 1, wherein immediately adjacent membrane layers are joined together across separating layers by ultrasound welding, punctual spot welds, bonding, punctual partial bonding, and/or by hot calendering.

16. The roofing underlay according to claim 1, wherein an adhesive area is provided on at least one edge at a bottom and/or at a top side of the roofing underlay.

17. The roofing underlay according to claim 1, wherein the roofing underlay is a roof cladding underlay or a roof lining membrane.

18. A method for production of a roofing underlay having at least one outer nonwoven layer, at least one inner nonwoven layer and at least one microporous membrane layer based on a polyolefin plastic, wherein the membrane layer is arranged between the outer nonwoven layer and the inner nonwoven layer, wherein at least one further microporous membrane layer based on polyolefin plastic is provided between the outer nonwoven layer and the inner nonwoven layer and the at least one further membrane layer is separated from the membrane layer by a nonwoven separating layer, wherein the nonwoven separating layer is water-permeable.

19. The method according to claim 18, wherein immediately adjacent membrane layers are joined together across separating layers by ultrasound welding, punctual partial spot welds, bonding, punctual partial bonding, and/or by hot calendering.

20. The method according to claim 18, wherein an at least three-layer construction having the at least one outer nonwoven layer, the at least one microporous membrane layer and the nonwoven separating layer, is first produced by calendering and/or ultrasound welding, and an at least two-layer construction having the at least one inner nonwoven layer and the at least one further microporous membrane layer is produced in particular by ultrasound welding, and the at least two-layer construction is then joined to the at least three-layer construction by a punctual partial bonding and/or full-surface bonding, wherein the at least one further microporous membrane layer of the at least two-layer construction is facing the nonwoven separating layer of the at least three-layer construction.

21. The method according to claim 19, wherein the ultrasound welding is performed using sonotrodes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features, benefits and application possibilities of the present invention will emerge from the description of exemplary embodiments with the aid of the drawing and from the drawing itself. In themselves or in any given combination, all the described and/or depicted features form the subject matter of the present invention regardless of their statement in the claims or their reference to other claims.

(2) FIG. 1 shows a schematic cross sectional view of a roofing underlay according to the invention,

(3) FIG. 2 shows a schematic cross sectional view of another embodiment of a roofing underlay according to the invention,

(4) FIG. 3 shows a schematic cross sectional view of another embodiment of a roofing underlay according to the invention,

(5) FIG. 4 shows a schematic cross sectional view of another embodiment of a roofing underlay according to the invention,

(6) FIG. 5 shows a schematic top view of a roofing underlay according to the invention,

(7) FIG. 6 shows a schematic perspective view of the laid roofing underlay according to the invention when used as a roof lining membrane,

(8) FIG. 7 shows a schematic perspective view of the roofing underlay according to the invention when used as a roof lining membrane,

(9) FIG. 8 shows a schematic cross sectional view of the intermediate products of the roofing underlay according to the invention before being joined together.

DETAILED DESCRIPTION

(10) The roofing underlay 1 shown in FIG. 1 comprises an outer nonwoven layer 2 and an inner nonwoven layer 3. Between the outer nonwoven layer 2 and the inner nonwoven layer 3 is arranged a microporous membrane layer 4 based on a polyolefin plastic. Besides the first membrane layer 4, a further membrane layer 5 is arranged between the outer nonwoven layer 2 and the inner nonwoven layer 3. The two membrane layers 4, 5 are separated from each other by a separating layer 6.

(11) In the embodiment shown, the separating layer 6 is formed water-permeable that means not water-tight. Furthermore, in the embodiments shown it is provided that the separating layer 6 is embodied as a structure made of fibers, wherein a nonwoven is provided as the structure. In further embodiments (not shown), a water-permeable and/or membrane layer-free layer or a structure made of fibers is provided as the separating layer 6. Moreover, the separating layer 6 in the embodiments shown is air- and water vapor-permeable.

(12) It is not shown that the separating layer 6 is embodied as an especially perforated and/or open-pore foam and/or foam layer, and/or as a scrim and/or as a textile and/or as an adhesive which is applied in particular in a filamentous structure, in a fibrous structure and/or in a grid pattern.

(13) It should be pointed out that both the outer nonwoven layer 2 and the inner nonwoven layer 3 need not be embodied as a single layer. The outer nonwoven layer 2 and/or the inner nonwoven layer 3 may each basically also be embodied as multiple layers. But in the following, a single-layer embodiment of the nonwoven layers 2, 3 shall be assumed.

(14) The outer nonwoven layer 2 comprises the outside 10 of the roofing underlay 1. Accordingly, the inner nonwoven layer 3 comprises on its outside the inside 11 of the roofing underlay 1. The outside 10 of the roofing underlay 1 is facing toward the weathering side and the inside 11 of the roofing underlay 1 is facing toward the base surface and/or the roof substructure. The microporous membrane layer 4, 5 has microscopically tiny holes/openings, which are configured such that water vapor molecules can diffuse through them, yet which are small enough that water in the liquid state of aggregation cannot get through them. A microporous membrane layer 4, 5 is accordingly diffusion-open, water-tight and water vapor-permeable. The membrane layer 4 facing toward the outer nonwoven layer 2 protects the inner membrane layer 5 against damaging environmental influences, such as temperature influences, UV radiation, dampness and/or dust. The damaging environmental influences have an accelerating effect on the aging process of the membrane layer 4, 5.

(15) In a further exemplary embodiment, FIG. 4 shows that a plurality of membrane layers 5 is present between the outer nonwoven layer 2 and the inner nonwoven layer 3. The membrane layers 5 are each separated and/or decoupled from each other by means of separating layers 6.

(16) Moreover, in the exemplary embodiment shown it is provided that the microporous membrane layer 4 comprises polypropylene (PP) as the polyolefin plastic. In a further exemplary embodiment (not shown), it is provided that polyethylene (PE) is used as the material for the microporous membrane layer 4.

(17) According to the exemplary embodiment of FIG. 1, it is provided that the membrane layer 4, 5 has a thickness of 100 μm. In further variant embodiments (not shown), the membrane layer 4, 5 has a thickness in the range of 20 to 200 μm, preferably between 30 and 120 μm, further preferably between 35 and 100 μm. The grammage of the membrane layer 4, 5 is between 15 and 150 g/m.sup.2, preferably between 20 and 100 g/m.sup.2, further preferably between 20 and 50 g/m.sup.2.

(18) Moreover, FIG. 2 shows that the thickness of membrane layer 5, which is facing toward the inner nonwoven layer 3, is twice as great as the thickness of the membrane layer 4 facing toward the outer nonwoven layer 2. In further variant embodiments (not shown), the thickness of the membrane layer 5 facing toward the inner nonwoven layer 3 is between 50% and 200%, preferably up to 70%, further preferably up to 85% and especially at least substantially up to 100% greater than the thickness of the membrane layer 4 facing toward the outer nonwoven layer 2. Finally, it is understood that in further embodiments (not shown), it is provided that the thickness of the membrane layer 5 facing toward the inner nonwoven layer 3 is greater than that of the membrane layer 4 facing toward the outer nonwoven layer 2.

(19) Moreover, FIG. 3 shows that the thickness of the membrane layer 4 facing toward the outer nonwoven layer 2 is greater than the thickness of the membrane layer 5 facing toward the inner nonwoven layer 3. Moreover, FIG. 3 shows that the inner membrane layer 5 is half as thick as the outer membrane layer 8. In further embodiments (not shown), it is provided that the thickness of the membrane layer 4 facing toward the outer nonwoven layer 2 is greater, preferably by between 50% and 200%, further preferably by up to 70%, further preferably by up to 85% and especially at least substantially by up to 100%, than the thickness of the membrane layer 5 facing toward the inner nonwoven layer 3.

(20) Moreover, in the exemplary embodiments per FIGS. 1 to 4 it is provided that the grammages of the outer nonwoven layer 2 and the inner nonwoven layer 3 are different. In the exemplary embodiment shown in FIGS. 1 to 4, it is provided that the outer nonwoven layer 2 has a grammage of around 70 g/m.sup.2. In further embodiments (not shown here), it is provided that the outer nonwoven layer 2 has a grammage between 20 and 200 g/m.sup.2, preferably between 30 and 140 g/m.sup.2, further preferably between 40 and 100 g/m.sup.2, further preferably between 50 and 80 g/m.sup.2. In the exemplary embodiments shown in FIGS. 1 to 4, the inner nonwoven layer 3 has a lower grammage than the outer nonwoven layer 2. The grammage of the inner nonwoven layer 3 in the exemplary embodiment shown is 20 g/m.sup.2. In further embodiments, it is provided that the inner nonwoven layer 3 has a grammage between 1 and 150 g/m.sup.2, preferably between 5 and 100 g/m.sup.2, further preferably between 10 and 50 g/m.sup.2 and especially at least substantially less than or equal to 20 g/m.sup.2.

(21) In the exemplary embodiments shown, the separating layer 6 has the same thickness as the inner nonwoven layer 3. Furthermore, the separating layer 6 has a similar grammage to the inner nonwoven layer 3. The grammage of the separating layer 6 in the exemplary embodiment shown is 20 g/m.sup.2. In further variant embodiments of the roofing underlay 1, it is provided that the separating layer 6 has a grammage between 1 and 150 g/m.sup.2, preferably between 5 and 100 g/m.sup.2, further preferably between 10 and 50 g/m.sup.2 and especially at least substantially less than or equal to 20 g/m.sup.2. In the embodiments shown, the separating layer 6 is embodied as a nonwoven layer.

(22) Moreover, the roofing underlay 1 is selectively permeable, so that in the exemplary embodiment shown it is both water-tight and water vapor-permeable. The roofing underlay 1 has water-tightness for a water column between 0.8 and 40 m. In the exemplary embodiment shown, it has water-tightness for a water column of 15 m. In further embodiments, it is preferably provided that the roofing underlay 1 has water-tightness withstanding a water column between 0.9 and 30 m, further preferably between 1 and 20 m. However, the roofing underlay 1 in the embodiments shown has not only water-tightness but also water vapor permeability, which is characterized by the water vapor diffusion-equivalent air layer thickness. In the exemplary embodiment shown, the water vapor diffusion-equivalent air layer thickness (s.sub.d value) is around 5 cm. In further embodiments, it may be provided that the s.sub.d value varies between 0.01 and 1 m, preferably between 0.02 and 0.5 m, further preferably between 0.03 and 0.3 m.

(23) In the embodiment shown, both the nonwoven layer 2, 3 and the separating layer 6 comprise a thermoplastic material. Polyester (PS) is provided as the thermoplastic material. In further embodiments, the use of polyethylene (PE), polypropylene (PP) and/or polyethylene terephthalate (PET) is also provided. Finally, it is understood that the nonwoven layer 2, 3 and/or the separating layer 6 may also consist of the thermoplastic material.

(24) It is not represented that the membrane layers 4, 5 can be joined to the inner nonwoven layer 3 and/or to the outer nonwoven layer 2 by ultrasound welding. In the ultrasound welding, the use of punctual spot welds is preferred. Besides ultrasound welding, gluing is also possible as a method for the connection, especially a punctual partial spot bonding, and/or hot calendering.

(25) It is further not shown that the immediately adjacent membrane layers 4, 5 are joined together across separating layers 6 by means of ultrasound welding, especially with punctual spot welds. Besides ultrasound welding, it is provided that bonding and/or hot calendering can be used as the connection method, similar to the connecting of the membrane layers 4, 5 to the nonwoven layer 2, 3. For the bonding, a punctual partial spot bonding is employed.

(26) In particular, for the bonding it is possible to use the separating layer 6, formed in particular as an adhesive applied in a filamentous structure, in a fibrous structure, and/or in a grad pattern, as the bonding layer itself.

(27) It can be seen in FIG. 5 that the roofing underlay 1 has an adhesive area 9 on each of its lengthwise edges 7, 8. The two adhesive areas are situated on the same side of the roofing underlay 1. This adhesive area 9 serves for the subsequent joining together of the roofing underlays 1 when the roofing underlay 1 is used as a roof lining membrane and/or roof cladding underlay on a roofing structure. The adhesive area 9 may be provided both on the outside 10 of the roofing underlay 1 and on the inside 11 of the roofing underlay 1. Preferably, in an exemplary embodiment (not shown) when using the roofing underlay 1 as a roof lining membrane and/or roof cladding underlay, it is provided that the individual roofing underlays 1 are connected by a “glue-in glue” connection. In this connection, only the adhesive areas 9 are used for the water-tight connection of the roofing underlays 1.

(28) It is not shown that the adhesive area 9 can be covered preferably with a liner, such as siliconized paper. The adhesive area 9 can provide, in addition to a full-surface application as shown in FIG. 5, also a partial or spot application at the lengthwise edge on the roofing underlay 1 and/or on the outside 10 and/or on the inside 11 of the roofing underlay 1. In the exemplary embodiment shown, the width of the adhesive area 9 is around 5 cm. In further embodiments (not shown), it is provided in particular that the width of the adhesive area 9 varies between 3 and 10 cm.

(29) Furthermore, FIG. 6 shows the use of the roofing underlay 1 as a roof lining membrane. The roofing underlay 1 here is arranged on a roofing structure. The individual roofing underlays 1 are joined together in water-tight manner by the adhesive areas 9 provided. The outside 10 of the roofing underlay 1 is facing toward the weather and the inside 11 of the roofing underlay 1 is facing toward the rafters.

(30) Moreover, FIG. 7 illustrates the arrangement of the roofing underlay 1 on a roofing structure, wherein the inside 11 of the roofing underlay 1 faces the roofing structure.

(31) Furthermore, a method for production of a roofing underlay 1 is provided wherein the roofing underlay 1 per FIG. 1 comprises an outer nonwoven layer 2 and an inner nonwoven layer 3. Between the outer nonwoven layer 2 and the inner nonwoven layer 3 is arranged a microporous membrane layer 4 based on a polyolefin plastic. In addition, a further membrane layer 5 based on a polyolefin plastic is arranged between the outer nonwoven layer 2 and the inner nonwoven layer 3. The membrane layers 4, 5 are separated and/or decoupled from each other by a separating layer 6.

(32) Moreover, in an exemplary embodiment of the method (not shown), it is provided that adjacent membrane layers 4, 5 are joined together across separating layers 6 by means of to ultrasound welding and/or by bonding and/or by hot calendering. For the ultrasound welding, it is preferably provided to use punctual partial spot welds. In the version of the method where the membrane layers 4, 5 are bonded to the separating layer 6, a partial punctual bonding is provided. In an exemplary embodiment (not shown), it is provided that the adhesive and/or glue for the integral connection of the individual layers is a hot melt glue and/or a dispersion glue. The ultrasound welding is preferably performed by means of sonotrodes, which ensure single punctual welds.

(33) In a further embodiment, the adhesive itself may be provided as the separating layer 6, wherein the separating layer 6 as an adhesive layer firmly joins together the membrane layers 4, 5.

(34) Schematically, FIG. 8 illustrates how, in one variant embodiment of the method, an at least three-layer construction 12 is first produced from an outer nonwoven layer 2, a membrane layer 4 and a separating layer 6. When producing the three-layer construction 12, in a further embodiment, the joining of the individual layers is done by calendering and/or ultrasound welding. Furthermore, besides the production of the at least three-layer construction 12, the production of an at least two-layer construction 13 is provided, wherein the at least two-layer construction 13 comprises a membrane layer 5 and an inner nonwoven layer 3. In a further embodiment, the at least two-layer construction 13 is preferably produced by a punctual partial bonding and/or full-surface bonding. The at least three-layer construction 12 is joined to the at least two-layer construction 13, preferably using a punctual partial bonding and/or full-surface bonding for the joining process. After combining the at least three-layer construction 12 with the at least two-layer construction 13, the roofing underlay 1 forms. When joining the at least two-layer construction 13 to the at least three-layer construction 12, the separating layer 6 of the at least three-layer construction 12 is being joined to the membrane layer 5 of the at least two-layer construction 13. Of course, in further variant embodiments of the method (not shown), different joining methods may be provided for the individual layers. Lastly, in one step of the method, the joining of all layers to form a roofing underlay 1 is carried to out, or individual layered constructions 12, 13 are produced by means of various joining techniques.

REFERENCES

(35) 1 Roofing underlay 2 Outer nonwoven layer 3 Inner nonwoven layer 4 Microporous membrane layer 5 Further membrane layer 6 Separating layer 7 Lengthwise edge 8 Lengthwise edge 9 Adhesive area 10 Outside of roofing underlay 11 Inside of roofing underlay 12 Three-layer construction 13 Two-layer construction