Method, device and semi-finished product for producing prepared roofing for renewing rooves

Abstract

The invention relates to a method for producing prepared roofing for renewing rooves, comprising a glass-nonwoven based planar structure (1) containing cavities (2, 3, 4, 5, 6, 7) spaced at intervals, which is laminated with a bitumen-based planar structure (10), a plastic film (8) being interposed between said structures. Said method is characterised in that the plastic film (8) is applied in a first step to a glass-nonwoven based planar structure (1) that has a mineral coating on one flat surface, by the application of molten plastic during an extrusion coating process to the opposite flat surface from the surface with the mineral coating. In a subsequent step, the bitumen-based planar structure (10) is laminated onto the surface of the glass-nonwoven based planar structure (1) that faces towards the applied plastic film (8). This permits a cost-effective production. The invention also relates to appropriate embodiments of the method, to a device for carrying out the method and to a semi-finished product for producing the prepared roofing for renewing rooves.

Description

[0001] The invention concerns a method and a semifinished product for producing a renovation roof covering comprising vapor pressure compensating devices, with a nonwoven glass cloth-based planar structure which is laminated on to a bitumen-based planar structure with the interposition of a plastic film and which has openings arranged distributed at spacings and extending continuously from one flat side to the other flat side.

[0002] It is known for existing roof covers to be renovated by a renovation roof covering being applied to the existing roof cover. Such a renovation roof covering has a planar structure based on nonwoven glass cloth, of which a flat side is connected to a bitumen-based planar structure, with the interposition of a plastic film. The planar structure based on nonwoven glass cloth has openings which extend continuously from one flat side to the other. The operation of fitting the renovation roof covering is effected in such a way that it is laid on the roof cover, with its flat side which is remote from the bitumen-based planar structure. Then, heat is applied from the flat side of the renovation roof covering, which has the bitumen-based planar structure, for example by means of a torch, more specifically in such a way that the renovation roof covering is caused to adhere or is melted to the existing roof cover. Due to the effect of heat, the bitumen-based planar structure becomes partially liquid. The plastic film which covers over the openings in the nonwoven glass cloth-based planar structure melts away in that procedure so that the bitumen can penetrate through the openings and can become firmly joined to the surface of the roof cover to be renovated. The join is effected only in the region of the openings and thus partially and not over the full area involved, in such a way that vapor pressure equalisation is made possible in that manner. The openings in the nonwoven glass cloth-based planar structure are stamped out at regular intervals prior to final production and for example measure approximately 2.5 cm×7 cm.

[0003] It is known, for the production of a renovation roof covering of the above-indicated kind, to use a laminating installation or a manufacturing installation of another kind, wherein a nonwoven glass cloth-based planar structure having the openings, a plastic film and a bitumen-based planar structure are introduced into the installation simultaneously or in succession, and are joined to each other. It has been found that handling and introducing a thin plastic film in a laminating installation or manufacturing installations of another kind cause problems and often result in operational difficulties and disturbances.

[0004] The object of the invention is essentially that of making the known method of producing a renovation roof covering of the kind set forth in the opening part of this specification, more rational than hitherto.

[0005] In accordance with the invention, to attain that object, it is provided that a mineral coating is applied to the one flat side of the nonwoven glass cloth-based planar structure and the plastic film is applied to the other flat side of the nonwoven glass cloth-based planar structure provided with openings, by the application of plastic material in the molten condition in an extrusion coating process, and that the bitumen-based planar structure is laminated on to the side of the nonwoven glass cloth-based planar structure, that is towards the applied plastic film.

[0006] Application of the plastic film by applying plastic material in the molten condition is more rational and less expensive than introducing a plastic film into a laminating installation or a manufacturing installation of another kind, for the production of renovation roof coverings.

[0007] In regard to the openings provided in the nonwoven glass cloth-based planar structure, it can further be provided in accordance with the invention that, during the operation of applying the plastic film by applying plastic material in a molten condition in an extrusion coating process to the planar structure provided with openings, the pressing pressure applied to the side opposite to the side at which the plastic material is applied is of such a value that no plastic material applied is pressed through the openings.

[0008] In a further embodiment of the invention it can be provided that a polyethylene layer of a weight in relation to surface area in the range of between 15 g/m2 and 50 g/m2 is applied as the plastic film to the planar structure provided with openings. The density of the polyethylene applied in the extrusion process is preferably in the range of between 0.915 g/cm3 and 0.960 g/cm3.

[0009] In a further embodiment of the invention it can be provided that the plastic film to be applied in the molten condition in the extrusion coating process is applied to project beyond at least one side edge of the nonwoven glass cloth-based planar structure, in such a way that in that fashion the plastic film is caused to project beyond the edge of the nonwoven glass cloth-based planar structure. Such a projecting portion affords advantages in regard to the laying procedure by virtue of additional reliable overlap of the individual strips of roof covering.

[0010] As conventional extrusion coating installations are only designed for coating carrier materials of full surface area, in a further configuration, in regard to the openings provided in the nonwoven glass cloth-based planar structure, it is provided that the pressing roller of a laminating device used in the extrusion coating process has a nonstick coating.

[0011] In an advantageous embodiment of this feature it can be provided that the pressing roller is in the form of a rubber roller covered with a polytetrafluoroethylene-based tube. Alternatively it can be provided that the pressing roller is in the form of a rubber roller over which is glued a polytetrafluoroethylene-based band.

[0012] A further embodiment of the invention provides that the nonwoven glass cloth-based planar structure has on its flat side remote from the plastic film a nonstick application which is in the form of a mineral coating.

[0013] The invention further concerns a semifinished product for producing a renovation roof covering for renovating existing roof covers or the like comprising a first material web portion which forms the semifinished product and which has a nonwoven glass cloth-based planar structure with openings which are arranged distributed at spacings and which extend from one flat side to the other, to the one flat side of which, to provide a renovation roof covering, a second material web portion in the form of a bitumen-based planar structure is fixedly connected, with the interposition of a plastic film. In accordance with the invention it is provided that the plastic film is fixedly applied on a flat side of the nonwoven glass cloth-based planar structure, more specifically preferably in that plastic material has been applied in a molten condition in an extrusion coating process to a flat side of the nonwoven glass cloth, wherein the openings in the nonwoven glass cloth-based planar structure are covered over by the applied plastic film. In a further configuration of the invention the flat side opposite to the flat side with the applied plastic film has a nonstick application in the form of a mineral coating.

[0014] The invention is described in greater detail by way of example hereinafter with reference to the drawings in which:

[0015] FIG. 1 is a diagrammatic plan view of an embodiment of a semifinished product according to the invention for the production of a renovation roof covering,

[0016] FIG. 2 shows a sectional view taken along section line II-II in FIG. 1 on an enlarged scale, and

[0017] FIG. 3 is a diagrammatic sectional view through a renovation roof covering which is applied to an existing roof cover but which has not yet been glued or melted to the existing roof cover.

[0018] FIG. 1 shows a plan view of a semifinished product in accordance with the invention. A nonwoven glass cloth-based planar structure 1 has openings 2, 3, 4, 5, 6, 7 which are arranged distributed at spacings and which are continuous from one flat side to the other through the planar structure. One of the two flat sides is fixedly joined to a plastic film 8 which also covers over the openings 2 through 7. The flat side of the nonwoven glass cloth-based planar structure 1, which is opposite to the plastic film 8, has a mineral coating 9. The plastic film 8 has been applied to the planar structure 1 provided with openings, by the application of plastic material in a molten condition in an extrusion coating process, more specifically in such a way that the openings 5 through 7 are also covered over by the plastic film 8.

[0019] The article shown in FIG. 1 or FIG. 2 is a semifinished product. To produce a renovation roof covering, a bitumen-based planar structure 10 is applied to the plastic film 8. That affords a renovation roof covering which is generally identified by reference 11 and which, for renovating an existing roof cover 12 (FIG. 3), is applied to the surface 13 thereof, with the flat side having the mineral coating 9. The fixing of the renovation roof covering 11 on the surface 13 is effected by warmth or heat being supplied (for example by a torch) to the renovation roof covering 11, from its surface identified by 14. That warmth or heat destroys the plastic film 8 in the region of the opening 5, and hot and liquid bitumen which issues from the bitumen-based planar structure 10 penetrates through the opening 5 (and naturally also through the other openings) so that the renovation roof covering is caused to adhere or is fused firmly to the surface 13 of the roof cover 12 to be renovated, in the region of the openings.

[0020] The thickness dimensions of the individual components shown in FIGS. 2 and 3 relative to each other are only selected to make the drawing clear and do not correspond to the actual conditions involved.

Claims

1. A method of producing a renovation roof covering (11) with vapor pressure compensating devices, comprising a nonwoven glass cloth-based planar structure (1) which is laminated on to a bitumen-based planar structure (11) with the interposition of a plastic film (8) and which has openings (2, 3, 4, 5, 6, 7) which are arranged distributed at spacings and extending from one flat side to the other, characterised in that a mineral coating (9) is applied to the one flat side of the nonwoven glass cloth-based planar structure (1) and the plastic film (8) is applied to the other flat side of the nonwoven glass cloth-based planar structure (1) provided with openings, by the application of plastic material in the molten condition in an extrusion coating process, and that the bitumen-based planar structure (10) is laminated on to the side of the nonwoven glass cloth-based planar structure (1), that is towards the applied plastic film (8).

2. A method as set forth in claim 1 characterised in that during application of the plastic film (8) by applying plastic material in the molten condition in the extrusion coating process to the planar structure (1) provided with openings the pressing pressure applied to the side opposite to the side at which the plastic material is applied is of such a value that no applied plastic material is pressed through the openings (2, 3, 4, 5, 6, 7).

3. A method as set forth in claim 1 or claim 2 characterised in that the plastic film which is to be applied in the molten condition in the extrusion coating process is applied projecting beyond the planar structure (1) at one longitudinal side or at both longitudinal sides (preferably about 15 cm).

4. A method as set forth in one of claims 1 through 3 characterised in that a polyethylene layer of a weight in relation to surface area approximately in the range between 15 g/m2 and 50 g/m2 is applied to the planar structure provided with openings.

5. A method as set forth in one of claims 1 through 4 characterised in that the density of the polyethylene applied in the extrusion process is approximately in the range of between 0.915 g/cm3 and 0.960 g/cm3.

6. A device for carrying out the method as set forth in one of claims 1 through 5 characterised in that the pressing roller of a laminating apparatus used in the extrusion coating process has a nonstick coating.

7. A device as set forth in claim 6 characterised in that the pressing roller is in the form of a rubber roller covered over with a polytetrafluoroethylene-based tube.

8. A device as set forth in claim 6 characterised in that the pressing roller is in the form of a rubber roller with a polytetrafluoroethylene-based band glued thereover.

9. A semifinished product for producing a renovation roof covering (11) for renovating existing roof covers (12) or the like, preferably for use in a method as set forth in one of claims 1 through 5, comprising a first material web portion which forms the semifinished product and which has a nonwoven glass cloth-based planar structure (1) with openings (2, 3, 4, 5, 6, 7) which are arranged distributed at spacings and which extend through the planar structure (1) from one flat side thereof to the other, to the one flat side of which, for providing the renovation roof covering, a second material web portion in the form of a bitumen-based planar structure (10) is fixedly joined, with the interposition of a plastic film (8), characterised in that the plastic film (8) is fixedly applied to a flat side of the nonwoven glass cloth-based planar structure (1), preferably by applying plastic material in the molten condition in an extrusion coating process.

10. A semifinished product as set forth in claim 9 characterised in that the flat side opposite to the flat side of the planar structure (1) with plastic film (8) applied thereto has a mineral coating.

11. A semifinished product as set forth in claim 9 or claim 10 characterised in that the plastic film (8) projects beyond at least one side edge of the nonwoven glass cloth-based planar structure (1).