EP0399952B1 - Strip for making a construction watertight - Google Patents

Abstract

For sealing or covering openings in a construction, a permanently elastic strip consisting of a base layer (1) and a foamed-material layer (2) of open-cell foam structure is used. The foamed-material layer (2) is, on the one hand, watertight and allows, on the other hand, water vapour to pass through. The foamed-material layer is preferably composed of PVC and has a diffusion resistance value (SD) equal to or less than 1.3 m. <IMAGE>

Description

The invention relates to a permanently elastic web for sealing a building and the use of a material web according to claim 15.

Permanently elastic material webs for sealing structural joints have been known and used for many years. For example, the German utility model G 77 03 332 a sealing strip for joints between components, in which the surface of the tape is provided with corrugations in the area of the bond. The basis for the formation of such seals is DIN 1854 018 540 (October 1973) for the Federal Republic of Germany.

From German utility model G 81 34 333 it is known to provide permanently elastic tapes for joints with a stretchable fabric. The fabric is embedded just below the surface and is used, among other things, to protect the tape against mechanical stress, e.g. to make them more resistant when walking.

From DE-A-18 023 73 a composite seal is known which consists of two elastic materials without a carrier layer. One of the layers is impermeable to water and the other layer is permeable to water. However, the overall arrangement contains a number of water passages, so that a seal is created in which water is passed through a filter. The purpose of this foam combination is that one of the foam layers can rot in a targeted manner.

For sealing larger openings, especially in the area of pitched roofs, material webs with different characteristics are mainly used today: The sealing on the inside is carried out by means of a vapor barrier. Mostly polyolefin (polyethylene) foils are applied under thermal insulation materials. The diffusion resistance of such vapor barriers is approximately S _D ≧ 130 m.

Sealing to the outside, that is mostly above the thermal insulation, is often implemented today with sealing sheets with a diffusion resistance S _D between 1.3 and 130 m. Such material webs are classified as a "vapor barrier". It is necessary to provide a cavity between the sealing membrane and the roof skin.

To improve the vapor permeability of sealing membranes, they are perforated mechanically or by electrical spark discharge. Such perforated sheets can be welded with the usual methods (hot air or heating wedge). Such a weldability is important with regard to the reliable and permanent connection of several webs. The perforation of the webs is, on the one hand, quite complex and, on the other hand, there are only selective vapor passages in the perforation area, which can lead to condensation in the event of more steam.

The problem with all known waterproofing membranes for sealing buildings (in the form of narrow or wide membranes) is the partially opposing requirement for the sealing behavior. For example, Polysulfide rubber or polyurethane good permanently elastic joint tapes. However, these bands tend to condense.

The object of the invention is to avoid the disadvantages of the known, in particular to propose a web for sealing a building that is simple and economical to manufacture has sufficient mechanical strength for the intended use, is waterproof and still avoids problems caused by trapped water vapor.

According to the invention, this is achieved primarily by a material web according to the characterizing part of claim 1.

In its approach, the invention deliberately and surprisingly turns away from the prior art: Instead of the mechanically stressable, permanently elastic tape used for sealing tapes, e.g. according to DE-GM 81 34 333 is still provided on the surface with a fabric for protection, the invention proposes the use of a sheet of open-cell foam. It has been shown in accordance with the invention that open-cell foam is outstandingly suitable as a covering sheet: on the one hand, the foam layer ensures sufficient water-tightness, e.g. against rainwater. On the other hand, the open-cell structure allows optimal steam passage, so that moisture that has penetrated can quickly escape through the web. In the area of the connection, especially the gluing to the structure, the web has a carrier layer, which ensures the required strength. The carrier layer can also optimally be used as a substrate during manufacture, i.e. be used when foaming the foam layer. In addition, the backing layer takes on mechanical forces when welding or gluing and e.g. even if the sealed opening changes due to expansion, so that the foam layer is protected from destruction.

Nevertheless, the web can be welded using thermoplastic material for the foam layer.

The use of a textile backing layer, particularly a knitted fabric or a nonwoven, is particularly advantageous. The fleece or the knitted fabric can be produced in such a way that the stretchability, especially the stretching direction of the backing layer, roughly matches the stretchability of the foam layer. Before the foam layer can tear under load, the backing layer absorbs the mechanical forces. Depending on the application, especially if less demands are made on the elasticity and elasticity of the tape, a fabric, a fleece, a paper layer or another carrier material can also be used.

The web according to the invention can be produced particularly advantageously if a nonwoven is used as the carrier layer, which is immersed in a flowable, prepared thermoplastic material and thereby coated.

Foamed PVC is particularly suitable as a foam layer with regard to economical production, diffusion and durability. The open-cell structure of the foam can be achieved particularly reliably using a mechanical gassing process.

Depending on the application, other plastics can also be used, e.g. Latex made of polyurethane or acrylate can be used advantageously.

The use of foam layers with a diffusion resistance value S _D of 1.3 m or less has proven particularly useful. According to SIA standard 280, test No. 5, the diffusion resistance (the diffusion-equivalent air layer thickness) S _{D is} calculated from µ xd, where µ is the diffusion resistance number and d is the material thickness in m.

Carrier layers with a diffusion resistance of S _D = 0.050 to 1.0 m can be used very particularly advantageously for the invention.

Foam layers with good mechanical properties with diffusion properties according to the invention can be produced if the foam layer is 0.4 to 1.3 mm, preferably 0.5 to 0.9 mm thick.

Figur 1

die schematische Darstellung eines dauerelastischen Bandes mit den Merkmalen der Erfindung,

Figur 2

die schematische Schnittdarstellung einer Bauwerksfuge, die mit einem erfindungsgemässen Band abge dichtet ist,

Figur 3

ein abgewandeltes Ausführungsbeispiel der Erfindung.

Figur 4

die schematische Darstellung einer Dach-Dichtungsbahn mit den Merkmalen der Erfindung, und Figur 5 die Anordnung gemäss Figur 4 in der Draufsicht.

The invention is explained below in exemplary embodiments with reference to the drawings. Show it:

Figure 1

the schematic representation of a permanently elastic band with the features of the invention,

Figure 2

the schematic sectional view of a building joint, which is sealed with a tape according to the invention,

Figure 3

a modified embodiment of the invention.

Figure 4

the schematic representation of a roof sealing membrane with the features of the invention, and Figure 5 shows the arrangement according to Figure 4 in plan view.

According to FIG. 1, a foam layer 2 made of an open-cell PVC foam is applied to a carrier layer 1 made of a knitted fabric made of synthetic fibers. The carrier layer 1 is rot-proof due to the synthetic fiber material used. In addition, it is vapor-permeable in every respect, so that it forms practically no resistance to water vapor passing through. The carrier layer 1 is approximately 0.25 to 0.50 mm thick. The foam layer 2 is embedded in the surface of the knitted fabric of the carrier layer 1. The total thickness of the tape is preferably about 0.75 mm.

The PVC foam is open-celled with a size of the individual cells of approximately 0.002 mm to 0.1 mm.

The joint edges are used to seal structural joints coated with an adhesive or contact adhesive, whereupon the permanently elastic tape with the carrier layer 1 is applied to the joint area and glued there.

FIG. 2 shows a modified exemplary embodiment, in which a permanently elastic layer 3 was already applied to the underside of the carrier layer 1 during the production process. The tape is supplied ready for gluing and there is no need to apply glue. As can be seen from FIG. 2, the tape with the backing layer 1 is glued to the two structural parts 4 and 5, so that the tape is held in the area of the joint 6 by the backing layer 1. Mechanical stress, e.g. by changing the distance of the building parts 4 and 5 due to thermal expansion, is absorbed by the carrier layer 1. Due to the knitted fabric used, the carrier layer 1 is sufficiently elastic. Water vapor in the joint 6 can easily pass through the carrier layer 1 and the open-cell foam layer 2, so that the joint 6 is reliably dehumidified. The foam density of the PVC foam of the foam layer 2 according to FIG. 2 is 0.60 to 0.90 g / ml, which results in excellent diffusion properties with good mechanical strength and reliable watertightness.

FIG. 3 shows a permanently elastic tape with backing layer 1 and foam layer 2 analogous to the exemplary embodiment according to FIG. 2. Two adhesive layers 3 are applied at intervals on the underside of the backing layer 1. Each of the layers 3 is covered by a cover strip 7, which prevents the layer 3 from drying out or losing its adhesive properties. Only immediately before application to structural parts 4 and 5 is the strip 7 removed from each of the adhesive layers 3.

Figure 4 shows the schematic representation of an under-roof sealing membrane in cross section. A glass fleece is provided as carrier layer 1, which has been coated by dipping with a foam layer 2 made of open-cell EVA foam. To reinforce the glass fleece, a scrim 1 a or a fabric made of synthetic fibers is provided, which is attached to the fleece 1 on one side. It can be seen from FIG. 5 that the scrim 1 a can absorb tensile stresses and thus relieves the load on the fleece 1. The scrim 1 a offers practically no resistance to the passage of steam. The fleece 1 is also extremely breathable and also elastic.

The glass fleece is also rot-proof and, from this point of view, also ideally suited for the application. The scrim or knitted fabric 1 a can be placed on the fleece 1 or otherwise connected to it. E.g. it could be sewn on. It would also be advantageous to design the backing layer 1 as a knitted fabric or as a knitted fabric (e.g. Malimo technique).

The carrier layer 1 can also be a nonwoven made of natural fibers, e.g. Cotton, cellulose or a mixture of natural fibers and synthetic fibers or with a reinforcing fabric or scrim made of synthetic fibers.

The open-cell foam layer 2 is produced by foaming mechanically incorporated air (whipped foam method). In contrast to the blowing agent foaming, in which a blowing agent gas is split off in the heat, which leads to predominantly closed foam structures, foamed structures with very high open cells are achieved with mechanically incorporated air.

To produce the foam layer 2 according to the invention, it is therefore proposed to use compressed air in plastisols or Incorporate dispersions. The incorporation should take place in such a way that there is an even distribution and thus a uniform porosity. Known systems for foam production in this way can be used. These usually work according to the so-called rotor / stator system. The dispersion announced by a pump or the plastisol is thoroughly mixed with air in a mixer head, which is composed of a stator and a rotor. The stator and rotor are provided with pins for foam formation. Such mixer heads are also often cooled.

The open-celled whipped foam can also be applied to the carrier substrate by coating or brushing instead of by dipping. Such foams can also be made from latices on a different thermoplastic basis, e.g. B. from polymers of urethanes, acrylates or copolymers of ethylene (EVA) and mixtures thereof.

The new sheet can be made particularly watertight or particularly reliably watertight if a lacquer or impregnation is provided on the surface at least on one side (on the outside). Polymers of VCVA copolymers, acrylate, urethane, silicones or ethylene copolymers as well as their mixtures have proven successful.

The following mixtures result in particularly suitable compounds for the production of open-pored whipped foams:

The blow foams in the various examples have enclosed air bubbles in the order of magnitude of 0.002 mm to 0.30 mm.

The blow foams were produced in a dynamic foam machine of the type AIR-O-Matic, S1500.

Of course, the joint tapes according to FIGS. 1-3 can also be made wider in order to be used for sealing steep roofs or walls. It is also provided that the sheets according to FIGS. 4 and 5 are designed as narrow strips for sealing joints.

Claims (15)

1. Strip for sealing of a construction (6), characterized by a support layer (1) for taking up the tensile forces in the case of mechanical loading and a watertight foam layer (2), with open-celled foam structure and a diffusion resistance value (S_d) of equal to or less than 1,3m, applied on top of said support layer.
2. Strip according to claim 1, characterized in that the support layer (1) is a flat article of textile.
3. Strip according to claim 2, characterized in that the support layer (1) is a knitted fabric.
4. Strip according to claim 3, characterized in that the support layer (1) is a non-woven fabric.
5. Strip according to claim 4, characterized in that the non-woven fabric contains glass fibers.
6. Strip according to claim 4, characterized in that the non-woven fabric contains natural fibers of cotton and/or rayon fiber.
7. Strip according to one of the preceding claims, characterized in that the non-woven fiber is reinforced by a lay or by a weave of synthetic fibers.
8. Strip according to one of the preceding claims, characterized in that the foam layer (2) is an opened-celled PVC foam.
9. Strip according to claim 8, characterized in that the open-celled foam layer (2) is manufactured from a latex of thermoplastic material.
10. Strip according to claim 9, characterized in that the thermoplastic material contains polymers of urethane and/or acrylates and/or copolymers of ethylene (EVA) or vinyl chloride (VSVAC).
11. Strip according to one of the preceding claims, characterized in that the foam layer (2) is between 0,4 and 1,3mm thick.
12. Strip according to claim 11, characterized in that the foam layer (2) is between 0,5 and 0,9mm thick.
13. Strip according to one of the preceding claims, characterized in that, cross sectionally, on the side of the support layer (1), lying opposite to the foam layer (2), at least one adhesive layer (3) is provided for connection of the strip to the components of the construction (5, 6).
14. Strip according to one of the preceding claims, characterized in that it is, at least on one side, provided with a water repelling coating.
15. Application of a material strip with a support layer, in particular a flat textile article, and a watertight and open-celled foam material layer, for sealing of constructions against the incursion of water, provided upon said support layer, the foam material layer possessing a diffusion-resistance value (S_d) of equal to or less than 1,3m.

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