The precompressed sealing tape for sealing a joint has an elastically re-expandable foam strip. The sealing tape also has a sheet-like wrapping, which at least partially surrounds the foam strip, and a strip-like element, which is arranged in the area of a lower transverse surface of the foam strip and which has greater flexural strength than the foam strip. A first section of the sheet-like wrapping is arranged between the lower transverse surface of the foam strip and the strip-like element.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority based on European patent application EP 09 178 899.2, filed Dec. 11, 2009.

FIELD OF THE INVENTION

The invention relates to a precompressed sealing tape for sealing a joint such as that between a frame profile of a window or a door and the wall of a building.

BACKGROUND OF THE INVENTION

A precompressed sealing tape, which consists of an elastically re-expandable foam strip of rectangular cross section, which, in the compressed state, is completely surrounded by a wrapping formed by a sheet of plastic, is known from EP 1 131 525 B1. The sheet of plastic forms a tear-off tab extending in the longitudinal direction of the sealing tape, for which purpose the sheet is bonded to itself to form a predetermined tear site. To hold the foam strip inside the pocket formed in this way, it is adhesively bonded on its bottom surface to the wrapping, and the bottom surface of the wrapping in turn can be adhered to a frame profile by separate adhesive means such as double-sided adhesive tape.

Sealing tapes of this type are bonded to the frame profile to be sealed, and after the frame profile has been installed in the rough opening in the wall of the building, the wrapping is torn open to allow the foam strip to recover elastically and thus to seal off the frame profile against the wall. In the case of these known sealing tapes, however, it is disadvantageous that they can be produced only in relatively narrow widths, because otherwise the recovery force of the precompressed sealing tape produces an oval-to-round shape inside the wrapping, which is unsuitable for installation. In association with the continually increasing requirements on sealing in buildings, however, it is desirable to provide precompressed sealing tapes in any desired width to achieve higher sealing values, better thermal insulation, and better sound damping.

WO 98/45565 A describes a sealing strip of foam material, which is surrounded by a wrapping. A stiff layer of cardboard or plastic can also be provided in the wrapping. After the sealing strip has been loosely laid in the joint to be sealed, the sheet-like wrapping is opened, and the foam strip expands slightly into the joint.

These embodiments suffer from the disadvantage that the stiff layer remaining in the joint does not meet high demands on thermal insulation, nor does it provide high sealing values, and therefore the overall sealing element is unsuitable for long-term use.

A sealing tape which consists of a surface strip for attachment to a frame profile with a foam strip arranged on top of the surface strip is described in U.S. Pat. No. 4,204,373. The foam strip is covered by a sheet of paper or plastic, which is adhered to the surface strip and holds the foam strip in the compressed state. Rip cords, which can be used to tear open the sheet after the frame profile equipped with the sealing tape has been installed in the building structure, extend along the edge of the cover sheet.

Shortcomings of these prior art designs include the large amount of space which the sealing tape occupies on both sides.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a precompressed sealing tape which is simple in design and easy to handle, which can be delivered in any desired width, and which can be easily applied and transported.

According to an aspect of the present invention, the sealing tape comprises an elastically re-expandable foam strip, extending farther in a longitudinal direction than in a transverse direction. The sealing tape includes two lateral surfaces and first and second transverse surfaces, which connect the lateral surfaces to each other. The sealing tape further includes a sheet-like wrapping, which at least partially surrounds the foam strip, and a strip-like element, which has a greater flexural strength in the transverse direction than the foam strip. The strip-like element is arranged in an area of the first transverse surface of the foam strip. A first section of the sheet-like wrapping is arranged between the first transverse surface of the foam strip and the strip-like element.

It is desirable and preferred that the compressed rectangular shape of the foam strip remains preserved even when the sealing tape is very wide. It is also desirable that the amount of space occupied by the sealing tape before it is used is minimal in all directions.

In a preferred embodiment, the first transverse surface of the foam strip is permanently connected to the strip-like element. This produces a reliable connection between the two layers and prevents the layers from slipping with respect to each other.

So that the tape can be attached to the frame component to be sealed, a fastening means for fastening the strip-like element to the structural component is provided in the area of the side of the strip-like element which faces away from the first transverse surface of the foam strip. Thus the sealing tape can be pre-mounted on the frame component, and after the frame component has been inserted into the opening in the building, the only additional step necessary is to open the wrapping to allow the foam strip to expand.

An especially simple and preferred way of attaching the sealing tape to the structural component is to use a double-sided adhesive strip as the fastening means. This adhesive strip can itself be covered by a cover sheet before the sealing tape is attached.

In one embodiment, the first section of the wrapping can be arranged between the first transverse surface of the foam strip and the strip-like element all the way across the first transverse surface.

In another embodiment, the first section of the wrapping can be arranged between the first transverse surface of the foam strip and the strip-like element only across a first part of the first transverse surface of the foam strip. Thus it is possible to produce a simple connection between the foam strip and the strip-like element, because most of the first transverse surface of the foam strip is available as a fastening surface.

In this embodiment, the sealing tape can be precompressed particularly effectively by arranging a second section of the wrapping between the first transverse surface of the foam strip and the strip-like element across a second part of the first transverse surface of the foam strip, specifically, a part which is opposite the first part of the transverse foam strip.

The sealing tape offers improved sealing properties if the strip-like element is made of foam and has a higher flexural strength that the foam strip.

It is advantageous for the strip-like element to have a flexural strength of more than 200 kPa, and preferably of more than 250 kPa. In another preferred embodiment, the strip-like element has a flexural strength of more than 300 kPa, and preferably of more than 400 kPa. In an especially preferred embodiment, the strip-like element has a flexural strength of more than 500 kPa, preferably of more than 1,000 kPa, and even more preferably of more than 2,000 kPa. In this way, the deformation of the sealing tape is effectively minimized even in the case of tapes of considerable width.

The wrapping preferably comprises a tear-off tab extending in the longitudinal direction, which serves as a pull element for opening the wrapping. Thus, after the sealing tape has been pre-mounted on the frame component to be sealed, the wrapping can be easily opened by the user.

It can be advantageous in each case for the wrapping to be provided with at least one predetermined tear site extending in the longitudinal direction of the sealing tape, preferably a perforation line, which makes it easier to open the wrapping.

In one embodiment, the sealing tape can be wound up into a roll, which greatly simplifies the transport and storage of the sealing tape.

If the structural component has already been equipped with an attached length of the sealing tape, installing the component at the construction site is extremely easy and uncomplicated. The structural component, furthermore, is then also provided with additional protection during transport.

DETAILED DESCRIPTION OF THE INVENTION

In some cases, the foam strips, wrappings, adhesive tapes, strip-like elements and cover sheets are shown in the drawings as if they were a certain distance apart, so that the individual elements which form the sealing tape can be clearly distinguished from each other. In these preferred embodiments, these elements lie directly on top of each other.

FIGS. 1-6show preferred embodiments illustrating a foam strip2, which, in the present preferred embodiments, has a rectangular cross section, is partially surrounded by a sheet-like wrapping4, and is held in a precompressed state. Foam strip2can be made of any desired open-cell or closed-cell soft foam, such as polyurethane or polyethylene, and can be impregnated to delay its recovery. A multi-layer arrangement of several different foam materials laminated onto each other is also conceivable, as is the arrangement of an impregnated foam layer on or next to a foam layer which is not impregnated. Different foam layers can be arranged adjacent to each other especially in the transverse direction of the sealing tape to give the sealing tape a different permeability to air in the inner area than in the outer area, for example, or to create a vapor diffusion gradient. Foam strip2extends farther in its longitudinal direction than in its transverse direction and comprises two lateral surfaces6and first and second transverse surfaces8,9(top surface8and bottom surface9), which connect the two lateral surfaces6to each other.

The material of wrapping4can be a foil or film material, a mesh fabric, paper, or some other material suitable for the application cited. Laminated sheets consisting of a layer of plastic laminated to a backing material (e.g., a nonwoven) or fabric-reinforced sheets can also be used. All these materials are described by the term “sheet-like”. Combinations of these materials are also possible. A thermoplastic film or a heat-shrink film, which contracts under the action of heat, however, is preferred. Such a heat-shrink effect can also be applied to only parts of wrapping4, e.g., in the area of top surface8of foam strip2, to make it taut and free of wrinkles. It is also possible for wrapping4to include reinforcement only in the area of top surface8of foam strip2.

In the preferred embodiments, in the area of at least one transverse surface, specifically at bottom surface9of foam strip2, a strip-like element10is positioned, which has a certain flexural strength in the transverse direction. The flexural strength should be high enough that strip-like element10can absorb the force which proceeds from or is caused by the attempt of foam strip2to expand. Under normal circumstances, such force would lead to a deformation of flexible wrapping4, causing it to resemble a tube with an oval or even a round cross section, without strip-like element10itself undergoing any significant deformation.

A foam which has a much higher flexural strength than foam strip2is provided as the material for strip-like element10. This is discussed in greater detail below. Cardboard or any other stiff material, including rigid plastic and the like, can be used in other preferred embodiments.

In certain preferred embodiments, strip-like element10should be flexible enough in the longitudinal direction that the sealing tape can be wound up into a roll.

In the examples ofFIGS. 1, 2, 5, and 6, a tear-off tab22is provided, which is formed by two sections of wrapping4, which are joined to each other. It is also possible to provide only one flag-like, extended section of wrapping4to serve as a tear-off tab. Wrapping4is opened by pulling on the tear-off tab, and foam strip2is thus free to expand. For this purpose, at least one predetermined tear site14, preferably a perforation line, can be provided in wrapping4in the area of lateral surface6from which tear-off tab22projects. The positions of predetermined tear sites14shown inFIGS. 1, 2, 5, and 6, however, are preferred, because in this case, after wrapping4has been opened, little or no material remains on left lateral surface6, and most of wrapping4slides along expanding foam strip2and arranges itself across right lateral surface6. Advantage can be taken of this effect when, for example, wrapping4comprises special sealing properties which serve to provide a special sealing effect for right lateral surface6, possibly in the form of a vapor diffusion barrier. Many other positions, however, can be imagined for predetermined tear sites14within the scope of the invention.

Wrapping4can also be reinforced in the area next to the predetermined tear site14by thermal hardening of the sheet, for example, by additional application of an adhesive strip, or by the thermal lamination of a plastic strip or plastic sheet. As a result, a mechanism is created which limits the extent to which wrapping4can tear, so that, after wrapping4has been separated at predetermined tear site14, it will not continue to tear in an uncontrolled manner in the area next to predetermined tear site14.

Wrapping4can also be torn open by pulling on tear-off tab22without the need for a predetermined tear site. Alternatively, wrapping4can be torn open with a rip cord, or the wrapping can be cut open with a knife or some other tool. Finally, the entire wrapping can be removed if wrapping4can be detached from foam strip2or from strip-like element10by pulling on it.

As shown in the drawings, tear-off tab22, can be arranged on the outside surface (on the left inFIGS. 1, 2 and 5-6), but, for reasons of better accessibility after installation of structural component12(e.g., for installations in a facade or outside wall), it can also be arranged on the inside surface. Two tear-off tabs22can also be provided, one on the inside surface and one on the outside surface, so that wrapping4can be opened from the inside or alternatively from the outside.

In the preferred embodiments shown, double-sided adhesive tape16is arranged between one of the transverse surfaces of foam strip2, specifically between bottom surface9and strip-like element10, and connects the two elements tightly together. The tight connection between foam strip2and strip-like element10can also be achieved by other means, such by thermoplastic lamination and other formation processes.

A fastening means18, which serves to attach the sealing tape to a component12such as a frame profile of a window to be installed in a building (seeFIGS. 2 and 6) is arranged in the area of strip-like element10. In the preferred embodiments according toFIGS. 1-5, fastening means18is in the form of an adhesive strip, the outside surface of which, i.e., the downward-facing surface, preferably is kept covered by a peel-off cover sheet20, such as silicone paper or the like, until the sealing tape is to be attached to component12. It should be appreciated that, in practice, the adhesive strip is very often realized by a layer of adhesive, which has been applied to a piece of silicone paper or the like, and which has then been laminated in this form to strip-like element10. In some cases, a scrim or a support film, nonwoven fabric, or the like can also be embedded in this adhesive layer to increase the tensile strength. The expression “adhesive strip” used herein should therefore also include adhesive layers of the type just described. The same applies to the term “adhesive tape”.

In the preferred embodiments ofFIGS. 1, 2, and 6, the wrapping overlays and covers the two lateral surfaces6and top surface8of the foam strip2. In the area of bottom surface9of foam strip2, there is in each case a first section24of wrapping4which extends over part of the bottom surface of foam strip2. In addition, a second section26of wrapping4extends between first transverse surface9and strip-like element10over a second part of first transverse surface, here bottom surface9of foam strip2, namely, the part which is opposite the first part. Two sections24and26of wrapping4therefore extend around the two lower edges of foam strip2, are folded over toward the inside, and attached there to foam strip2, preferably bonded with an adhesive, or laminated or welded, to foam strip2. Between two sections24,26of wrapping4, bottom surface9of foam strip2remains uncovered by wrapping4. InFIG. 1, this is where the double-sided adhesive tape16is attached. Adhesive tape16can also extend over the two sections24,26of wrapping4, as shown inFIGS. 2 and 6.

In principle, the sealing tape can be produced in the form of strips or in the form of rolls. In the case of especially stiff materials of the strip-like element10, however, the strip form is preferred.

FIGS. 2, and 6show a structural component12, to which the sealing tape has been attached. In a configuration such as this, the component12can be delivered to the construction site as a ready-to-install assembly. The connection between the sealing tape and component12is produced by fastening means18. InFIG. 2, fastening means18is the adhesive strip, from which cover sheet20has been previously peeled. InFIG. 6, fastening means18is a keder or plug-in profile, which ensures a reliable connection and which preferably is connected by pushing the side of the tape onto the component or engaging it within the component by insertion or other means.

The sealing tape may be preferably fastened to frame component12by fastening means18before the component is installed or possibly even before it is transported. After it has been installed on-site in the intended opening in the building, the only step then required is to open wrapping4by cutting it with a knife or by pulling on tear-off tab22. Strip-like element10(which is not usually expandable) fastened to frame component12remains unchanged, whereas foam strip2expands upward and produces the desired sealing effect in the joint. As this is happening, the part of wrapping4remaining in the joint slides along the expanded foam strip2and ultimately covers preferably at least part of its right lateral surface6in the final state.

The preferred embodiment shown inFIG. 3is usable only as roll material. In this case, first section24of wrapping4is arranged on the right outer edge area of bottom surface9of foam strip2and is bonded firmly in place. Wrapping4covers right lateral surface6of foam strip2and at least part of top surface8of foam strip2. In the area of top surface8, wrapping4is folded back on itself to form a first loop. A second section26of wrapping4located at the end of the loop is adhered tightly to top surface9of the foam strip2. The loop therefore forms a reserve of material for the displacement of wrapping4, the amount of which corresponds to the maximum desired expansion of foam strip2.

After the sealing tape has been unwound from the roll, there is only a limited amount of time available to attach the sealing tape to component12and to insert component12into the opening in the wall provided for it before the delayed expansion of foam strip2makes the sealing tape too large to insert into the opening. Because current impregnating materials make it possible to delay the expansion of foam strip2by several hours, however, this does not represent a significant limitation.

In the preferred embodiment shown inFIG. 4, a second wrapping28surrounds the sealing tape shown inFIG. 3. In this case, the sealing tape can also be produced in the form of a strip. Second wrapping28can also include a tear-off tab or be accessible to any other desired type of opening mechanism. Second wrapping28extends continuously along the bottom surface of strip-like element10and is bonded to it by means of an adhesive, for example, or by welding or by lamination, possibly only at one or two points. In this embodiment, adhesive strip18for fastening the sealing tape to structural component12is attached directly to second wrapping28.

In the preferred embodiment illustrated inFIG. 5, first section24of wrapping4extends all the way across between foam strip2and strip-like element10. First section24is attached to bottom surface9of foam strip2by a piece of double-sided adhesive tape16, whereas another piece of double-sided adhesive tape27produces the connection between first section24of wrapping4and strip-like element10. Instead of using adhesive tapes16,27to fasten wrapping4to foam strip2and to strip-like element10, the wrapping can also be bonded adhesively in some other way or welded or laminated in place. As also the case in the embodiments described herein (except for that ofFIG. 3), wrapping4prevents foam strip2from expanding and thus holds it in the precompressed state.

Many other embodiments of the present invention are also conceivable. The details discussed with reference to any one of the preferred embodiments illustrated inFIGS. 1-6can also be used in any of the other embodiments. Other designs are also conceivable, as long as at least one section of wrapping4is arranged between strip-like element10and foam strip2.

In practice, foam strips2are usually precompressed in such a way that, when they expand, they increase preferably by up to about 5-10 times the thickness which they had in the precompressed state. Often, use is made of only about half of this possible expansion to guarantee that the tape will rest reliably against the construction element facing the profile element to be sealed.

A foam which has greater flexural strength than foam strip2, preferably a much higher flexural strength, is provided as the material for strip-like element10. The strip-like element has a flexural strength of more than 200 kPa, preferably of more 250 kPa, and in a preferred embodiment the strip-like element has a flexural strength of more than 300 kPa. In other preferred embodiments, the strip-like element has a flexural strength preferably of more than 400 kPa, in another preferred embodiment the strip-like element has a flexural strength of more than 1,000 kPa, and in another preferred embodiment more than 2,000 kPa. In this way, the deformation of the sealing tape is effectively minimized even in the case of very wide tapes.

The material of foam strip2, however, has a flexural strength of less than 150 kPa, preferably of less than 125 kPa, and in another preferred embodiment, less than 100 kPa.

The flexural strength of the material of strip-like element10and of foam strip2is determined on the basis of the 3rd edition of the standard ISO 1209-2 from the year 2007. This international standard is usually used to determine the flexural strength of plastics, but may also be used in a somewhat modified form for determining the flexural strength of foam materials.

A steadily changing force is applied perpendicularly to the center of a test piece resting on two supports. The test piece therefore undergoes a certain deflection. The flexural strength is calculated from the measured force-versus-deformation curve (see Section 3 of ISO 1209-2). The testing device is described in detail in Section 4 (shown in FIG. 1 of ISO 1209-2). An example of a suitable testing device is model BZ2.5/TN1S from the Zwick Company in Ulm, Germany. The load cell used here can be, for example, the KAP-Z model for forces of up to 200 N.

The supports consist of two parallel cylindrical support elements, which are arranged on the same horizontal plane, and each of which has a radius of 15±1 mm. The support elements are longer than the test pieces are wide, and in the present case they are 80 mm long.

In the case of the present measurement, the distance L between the support elements is set at 85±2 mm and thus deviates from the value according to ISO 1209-2. The force-transmitting element has the same shape as the support elements. The other dimensions given in Section 5.1 of ISO 1209-2 have also been changed for the special application of measuring foams. Each measured foam test piece is a block with an edge length l of 150±3 mm, a width b of 40±2 mm, and a thickness d of 3±0.2 mm. The first set of test conditions described in Section 6 of ISO 1209-2 is used, i.e., measurement at 23±2° C. and 50±10% relative humidity. In contrast to the velocity of the movement of the force-transmitting element stated in Section 7 of ISO 1209-2, here it is moved downward at a speed of only 10±1 mm per minute. In addition, the force is measured up to a maximum deflection of the foam of 20 mm, and the maximum value FRof the force which occurs during the course of the measurement is recorded.

The calculation of the flexural strength R (in kPa) is carried out as described in Section 8.1 of the ISO 1209-2, i.e., by the use of the formula R=1.5FR·L/bd2·106, where FRis the maximum applied force in kN, L is the distance between the support elements in mm, b is the width of the test piece in mm, and d is the thickness of the test piece in mm.

At the specified values for L, b, and d, the measured force FRfor the material of strip-like element10and foam strip2results in the values given herein.

The embodiments shown inFIGS. 1-6are illustrated with a cross section of foam strip2of more-or-less idealized shape. In reality, top transverse surface8of foam strip2will extend at least slightly in the direction of a dome-like shape as a result of the pressure acting from within, so that the cross section of foam strip2in the precompressed state will assume a form which deviates to a certain extent, but not too severely, from that of a rectangle. A certain transverse bending (outward curvature) of stiff element10can also be observed in practice, especially in the case of very wide sealing tapes.

The invention has been described herein on the basis of a foam strip1with a rectangular cross section by way of example, because this makes it much easier to explain the invention and its various features. The term “rectangular” can also mean “square”. The person skilled in the art will appreciate, however, that the invention can also be realized in a corresponding manner with foam strips which have cross sections different from that of a rectangle. The cross-sectional shape of foam strip2indicated herein should therefore not be understood as limiting in any way.

While the present invention and its principles have been shown and described in connection with certain exemplary or specific embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications, alternatives, modifications and equivalent arrangements as will be apparent to those skilled in the art. Any such changes, modifications, alternatives, modifications, equivalents and the like may be made without departing from the spirit and scope of the invention.