Patent Application
20130187348
This application claims priority based on European patent application EP 12 152 236.1 filed Jan. 24, 2012.
The invention pertains to a sealing tape for sealing a joint and to a suitable production method
Sealing tapes of soft, flexible foam material are used generally in the construction industry to seal joints against drafts and driving rain. In professional building construction, sealing tapes of soft, flexible foam are used between window and door frames and a masonry wall. Such sealing tapes can be up to a few centimeters thick and are usually provided with a pressure-sensitive adhesive layer on the bottom, by which they can be adhered to the profiled framing elements of windows and doors. To facilitate the installation of the structural component provided with the sealing tape at the building site, sealing tapes of this type, which are delivered in a compressed state in rolls, are often impregnated with a material which delays the recovery of the foam from the compressed state to the expanded state.
To prevent the diffusion of water vapor and to improve the sealing effect against air, sealing tapes of the type indicated above must be provided with a vapor barrier. A sealing tape of open-pore material in the form of a rolled-up disk for sealing joints or gaps against drafts and driving rain is known from DE 196 41 415. At least one barrier layer is arranged inside the sealing tape to create a configuration in which the barrier layer and the adjacent open-pore areas form a row in the axial direction. The barrier layer therefore extends in the radial direction of the sealing tape roll, and the barrier can thus, after the sealing tape has been unwound from the roll, serve as a vapor diffusion barrier in the functional direction of the sealing tape, i.e., the direction which extends from the one lateral surface of the sealing tape to the other lateral surface of the sealing tape.
To produce a sealing tape of the latter type, barrier layers with a large surface area are formed by laminating and/or adhesively bonding sheets or webs of raw open-pore foam material in layered fashion to create laminated blocks. The laminated blocks are then cut at a right angle to the large barrier layers of lamination material and/or adhesive to form plates with barrier layers, so that, after the cutting operation, the barrier layers are parallel to one edge of the plate and extend vertically through the plate. A plate of this type is then wound up under compression into a roll, so that, on the circumference of the roll, the barrier layers and the open-pore material alternate with each other in the axial direction. Finally, the roll is cut into disks between the individual barrier layers. This procedure is relatively complicated and requires a high degree of dimensional stability of the foam material during processing and when it is being wound up into a roll, because otherwise, when the roll is cut into disks, there is the danger of damage to the barrier layers.
It is an object of the present invention to provide a sealing tape for sealing a joint which not only offers a low degree of permeability to air and a reduced degree of permeability to the diffusion of water vapor but is also especially easy and cheap to produce.
According to an aspect of the invention, the sealing tape for sealing a joint comprises
a top, a bottom, and two longitudinal sides, wherein a direction parallel to the top and bottom and transverse to the longitudinal sides defines a functional direction of the sealing tape;
at least one first foam strip and one second foam strip of a flexible foam capable of recovery after compression, the first and second foam strips arranged next to each other in the functional direction; and
a sheet-type strip serving to reduce a permeability of the sealing tape to diffusion of water vapor in the functional direction, the sheet-type strip arranged between the first foam strip and the second foam strip and comprising a section arranged substantially in the shape of a U or V, wherein a first limb and a second limb of the section of the sheet-type strip arranged substantially in the shape of a U or V extend toward the top of the sealing tape.
With this design, the sealing function is improved over that of conventional flexible foam tapes, wherein the task of equipping the flexible foam with the sheet-type strip can be easily automated.
The first limb of the substantially U-shaped or V-shaped section of the sheet-type strip is preferably bonded to at least certain areas of the side of the first foam strip facing the second foam strip, and the second limb of the substantially U-shaped or V-shaped section of the sheet-type strip is bonded to at least certain areas of the side of the second foam strip facing the first foam strip. As a result, the sheet-type strip is held securely in place, and the two foam strips are permanently connected to each other at least by the sheet-type strip, independently of any other design measure which may be provided.
It is especially preferred for the sheet-type strip to be laminated or adhesively bonded to the two foam strips.
As part of an especially simple production variant, the crest or apex of the substantially U-shaped or V-shaped section of the sheet-type strip is arranged inside the sealing tape.
The limbs of the substantially U-shaped or V-shaped section of the sheet-type strip preferably enclose an angle in the range of between 10° and 0°, more preferably an angle in the range of between 3° and 0°, when the sealing tape is in the fully expanded state. When the angle in question is 0°, the two limbs of the sheet-type strip rest directly against each other, so that it is impossible for any air to be trapped inside the sealing tape.
Accordingly, the limbs of the substantially U-shaped or V-shaped section of the sheet-type strip are substantially perpendicular to the functional direction and parallel to the longitudinal sides of the sealing tape. In this way, optimal use of the barrier properties of the sheet-type strip in the functional direction is guaranteed.
The crest or apex of the substantially U-shaped or V-shaped section of the sheet-type strip is preferably arranged within an area extending over a range of between 1 and 40%, more preferably over a range of between 5 and 20%, of the height of the sealing tape when the sealing tape is in the fully expanded state. This ensures that the barrier function of the sheet-type strip acts over almost the entire height of the sealing tape and simultaneously that enough space remains for a direct connection between the two foam strips.
In such cases, the foam strips arranged next to each other in the functional direction will thus be permanently connected to each other, directly or indirectly, in the area of the bottom of the sealing tape.
For example, a continuous layer, preferably of a stiff material, can be arranged in the area of the bottom of the sealing tape. The foam strips can be permanently attached to the continuous layer. As a result, a solid connection is produced between the foam strips. When a stiff layer is used, the stiffness makes it possible to form sealing tapes of practically any desired width and increases the number of ways in which the sealing tape can be attached to the corresponding frame section of the structural part to be sealed. The continuous layer can also be provided in the form of single-sided or double-sided adhesive tape, which connects the two foam strips to each other.
Alternatively or in addition, the foam strips arranged next to each other in the functional direction can be designed as integral parts of each other in the area of the bottom of the sealing tape, so that they thus form a continuous connecting web there.
The method for equipping a sealing tape blank with a sheet-type strip comprises the following steps:
providing a sealing tape blank comprising a layer of flexible foam, and further comprising a top, a bottom, and two longitudinal sides, wherein a direction parallel to the top and bottom and transverse to the longitudinal sides defines a functional direction of the sealing tape blank;
introducing at least one incision or recess into the layer of flexible foam beginning from the top of the sealing tape blank, thus dividing the flexible foam into at least two interconnected adjacent sections;
folding open two adjacent sections of the flexible foam laterally outward and applying the sheet-type strip to at least certain areas of the folded-open adjacent sections; and
releasing the two adjacent sections of the flexible foam to allow the flexible foam to recover and thus to allow the sheet-type strip to form a section of the sheet-type strip arranged substantially in the shape of a U or V.
This method for equipping a sealing tape blank with a sheet-type strip is especially easy and low in cost and can be carried out in completely automated fashion.
The step of folding open two adjacent sections of the flexible foam is preferably carried out by means of at least one displacement roll. The displacement roll folds the two adjacent sections of the flexible foam toward the sides of the sealing tape blank, each section being folded toward the side of the blank to which it is closer, therefore preferably in a direction perpendicular to that of the incision. This means that the folding-open step can be carried out easily by machine.
With respect to the automation of the process, it is also advantageous for the sheet-type strip to be applied to the folded-open sections of the flexible foam by means of at least one applicator roll.
The step of applying the sheet-type strip to at least certain parts of the folded-open sections can be accomplished preferably immediately after the folding-open step, and it is especially preferable for these two steps to be carried out in combination. In this case, the at least one displacement roll and the at least one applicator roll would be arranged directly one behind the other, and the foam web would be conducted past the at least one displacement roll first and briefly thereafter past the at least one applicator roll. This ensures that, at the time of application, the flexible foam is still retaining its folded-open position. It is also possible, however, in cases where foams impregnated to provide an especially long delay of the recovery process are being used, to allow the at least one displacement roll and the at least one applicator roll to perform their functions at points relatively far apart.
Additional features and advantages of the present invention can be derived from the following description, which refers to the drawings.
a-4c show in schematic fashion the sequence of steps of a preferred production method for the sealing tape according to the invention, in which a sealing tape blank is equipped with a sheet-type strip.
Each sealing tape comprises a top 2, a bottom 4, and two longitudinal sides 6, wherein a direction parallel to top 2 and bottom 4 and transverse to longitudinal sides 6 defines the functional direction (arrow F) of the sealing tape. It is in this functional direction F that the sealing tape is intended, after installation, to protect against driving rain and the passage of air as well as to limit, at least to a large degree, the diffusion of water vapor. Although this cannot be seen in
In the examples shown here, the sealing tape comprises two foam strips 8, 10 of a flexible foam capable of recovering its original shape after having been compressed. Two foam strips 8, 10 are arranged adjacent to each other in the functional direction F. It is also possible, however, to arrange more than two foam strips 8, 10 next to each other.
In the exemplary embodiments shown, foam strips 8, 10 of flexible foam have a substantially rectangular cross section, but any other suitable shape is also conceivable. Foam strips 8, 10 can be formed out of any suitable flexible open-cell or closed-cell foam such as foams of polyurethane or polyethylene, for example, and they can be impregnated to delay their recovery after compression. The weight by volume of these types of flexible foams is in the range of 20-200 kg/m3.
The material of first foam strip 8 can be different from that of second foam strip 10, so that, for example, the permeability to air of the sealing tape in the inner area is different from that in the outer areas or so that a vapor diffusion gradient is created. The width of foam strips 8, 10 can also be different as can their height or their degree and/or type of impregnation.
In practice, foam strips 8, 10 are usually precompressed in such a way that, when the pressure on them is released, they can expand preferably to a thickness which is approximately 5-10 times greater than that which they had in the precompressed state, although in many cases, to guarantee reliable contact with the building component opposite the profile element to be sealed, only about half of this capacity for expansion is actually used.
After the compressive force has been released by, for example, unwinding the sealing tape from the sealing tape roll, there is usually only enough time to install the sealing tape on the building component to be sealed and to place the component into the joint in the wall intended for it before the delayed expansion of foam strips 8, 10 makes the sealing tape too large to insert into the opening. Because current impregnation agents make it possible to delay the expansion of foam strips 8, 10 by several hours, however, this does not represent a significant limitation. When the sealing tape is in the form of strips, it is usually necessary to compress the strip before inserting it into the joint.
The sealing tape could basically also be attached to the structural component to be sealed before the component is transported to the construction site. In this case it would be necessary, however, to prevent the sealing tape from expanding by enclosing it in a wrapper (not shown). After installation of the component in the intended opening in the building, it would then be necessary merely to open the wrapper on site, whereupon foam strips 8, 10 expand outward and thus guarantee the sealing of the joint.
The sealing tape also comprises a sheet-type strip 12, which is arranged between two adjacent foam strips 8, 10 and bonded to them in such a way that it reduces or possibly even eliminates completely the permeability of the sealing tape to the diffusion of water vapor in the functional direction F. Sheet-type strip 12 comprises at least one section arranged substantially in the shape of a U or V, and the limbs 14, 16 of the U-shape or V-shape of sheet-type strip 12 extend toward top 2 of the sealing tape. In the completely expanded state of the sealing tape, limbs 14, 16 of sheet-type strip 12 (as shown in
First limb 14 of the section of sheet-type strip 12 arranged in substantially the shape of a U or a V is bonded to at least certain areas of the side surface of first foam strip 8 facing second foam strip 10, and second limb 16 of the section arranged substantially in the shape of a U or V is bonded to at least certain areas of the side surface of second foam strip 10 facing first foam strip 8. Sheet-type strip 12 is preferably bonded to foam strips 8, 10 by the use of an adhesive, but a lamination process could also be considered.
Sheet-type strip 12 consists preferably of a plastic such as polyethylene, polypropylene, polyvinyl chloride, or rubber. The term “sheet-type”, however, is intended to cover all possible other materials such as foamed plastic of, for example, polyethylene, polypropylene, or cellular rubber. In addition, the material of sheet-type strip 12 can consist of paper such as waxed paper or of aluminum or of a mesh fabric suitable for the purpose indicated. For example, laminated sheets consisting of a plastic sheet laminated to a backing material (such as a nonwoven) or fabric-reinforced sheets are also usable. Combinations of these materials are also possible. Especially preferred are air-tight sheets which seal off the joint toward the inside of the room and also significantly reduce the permeability to vapor diffusion. The thickness of sheet-type strip 12 is between 10 μm and 5 mm, preferably between 50 μm and 2 mm.
In the embodiments according to
When foam strips 8, 10 are in the expanded state, limbs 14, 16 of the section of sheet-type strip 12 arranged substantially in the shape of a U or V enclose an angle of preferably between 10° and 0°, and more preferably of between 3° and 0°. If the displacement cuts have been made cleanly during the production of the embodiments according to
In all cases, two foam strips 8, 10 are permanently connected to each other by sheet-type strip 12. In the embodiment according to
In fact, however, it is preferable for first foam strip 8 and second foam strip 10 to be permanently connected to each other, directly or indirectly, in the area of the bottom 4 of the sealing tape.
For example, as shown in
As the material of continuous layer 18, a foam which has a greater degree, preferably a much greater degree, of stiffness than foam strips 8, 10 is preferably provided. In addition, cardboard can also be considered, for example, but any other suitable stiff material such as a rigid plastic is also usable.
In the embodiment shown in
Conversely, it is advantageous in the case of the embodiment according to
In the embodiment of
A preferred method for producing the sealing tape will now be described with reference to
In
Now at least one incision 105 or recess extending from top 102 of sealing tape blank 100 is introduced into layer 107 of flexible foam by means of, for example, a knife 103, as a result of which at least two interconnected sections 108, 110 of flexible foam are formed. As explained further above, incision 105 or recess preferably extends into the sealing tape as far as the preferred area for the location of the crest or apex of the section of sheet-type strip 12 arranged substantially in the shape of a U or V. A simple displacement cut is preferred, but it is also possible to remove material.
Then, as indicated schematically in
A displacement roll of this type can have a special design (e.g., with a banana-like shape), or it can be specially arranged in such a way as to support the outward folding of sections 108, 110 of the flexible foam. The axis of the roll will usually be parallel to the functional direction F of sealing tape blank 100, but other arrangements with the axis at a slant to the functional direction, for example, are also conceivable. It is also possible to arrange several displacement rolls in a row.
The use of at least one pair of rolls which form a nip between them, through which sealing tape blank 100 is guided to fold open sections 108, 110 of flexible foam, is also conceivable. It is possible to imagine numerous other mechanisms which could be used to fold open the sections.
Then, as illustrated schematically in
The at least one applicator roll is arranged downstream from the at least one displacement roll. If the applicator roll is designed as a laminating roll, it will laminate sheet-type strip 12 to sections 108, 110 of the flexible foam. It can be advantageous to heat the laminating roll for this purpose. Sheet-type strip 12 can also be attached to the sections 108, 110 of the flexible foam by the use of an adhesive compound. In this case, too, it is advantageous for sealing tape blank 100 to be processed by means of a pressing roll, which presses sheet-type strip 12 onto the flexible foam.
The rotational axis of the applicator roll will usually be perpendicular to the direction in which sealing tape blank 100 is moving. Here again, it is also possible to use a pair of rolls which form a nip between them, through which the web of the sealing tape blank 100 passes.
It is especially preferable to carry out the step of applying sheet-type strip 12 to at least certain areas of folded-open sections 108, 110 of the flexible foam immediately after the folding-open step, and it is even more preferable to combine the two steps into one. For example, the at least one applicator roll can be arranged directly behind the at least one displacement roll, so that sections 108, 110 of the flexible foam are still in the laterally folded-open, flat-pressed state during the application of sheet-type strip 12. When impregnated flexible foams are used, this is not necessarily required, because, as a result of the impregnation, the flexible foam recovers only after a certain delay and thus sections 108, 110 of the flexible foam persist for a relatively long time in the laterally folded-open state.
Then two adjacent sections 108, 110 of the flexible foam are released, and the flexible foam is able to return to its original shape. This results in the formation of the substantially U-shaped or V-shaped section of sheet-type strip 12, wherein limbs 14, 16 of the section of sheet-type strip 12 arranged substantially in the shape of a U or V extend toward top 102 of sealing tape blank 100. The sealing tape in
It should be clear that two adjacent sections 108, 110 of sealing tape blank 100 correspond to two foam strips 8, 10 of the finished sealing tape. Top 102, bottom 104, and sides 106 of sealing tape blank 100 similarly correspond to top 2, bottom 4, and longitudinal sides 6 of the finished sealing tape. To this extent, the description given previously for the sealing tape under reference to
There are also other methods which can be used to produce the sealing tapes according to the invention.
Reference throughout this specification to “the embodiment,” “this embodiment,” “the previous embodiment,” “one embodiment,” “an embodiment,” “a preferred embodiment” “another preferred embodiment” “the example,” “this example,” “the previous example,” “one example,” “an example,” “a preferred example “another preferred example” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. Thus, appearances of the phrases “in the embodiment,” “in this embodiment,” “in the previous embodiment,” “in one embodiment,” “in an embodiment,” “in a preferred embodiment,” “in another preferred embodiment,” “in the example,” “in this example,” “in the previous example,” “in one example,” “in an example,” “in a preferred example,” “in another preferred example, and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments or examples. One skilled in the relevant art will recognize that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment or example. In other instances, additional features and advantages may be recognized in certain embodiments or examples that may not be present in all embodiments of the invention.
While the present invention has been described in connection with certain exemplary or specific embodiments or examples, it is to be understood that the invention is not limited to the disclosed embodiments or examples, 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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 12152236.1 | Jan 2012 | EP | regional |
