EP3404156B1 - Method for producing sealing strip - Google Patents

Description

The present invention relates to a method of manufacturing a sealing tape. .From the prior art, a wide variety of sealing tapes for a wide variety of applications are known. Thus, sealing tapes are also known which have a coating on a foam carrier, which is intended to reduce vapor diffusion, for example. Various procedures for the production of such sealing tapes are known from the prior art. For example, it is known that a foam carrier is cut open and a film is introduced into a cut area.

An example of such a method and a corresponding device is from DE 10 2015 116 667 A1 known. In this case, the foam carrier is cut open during its transport along a predetermined transport direction.

An alternative procedure is out EP 2 107 176 A1 known. According to the method described therein, the foam carrier or the foam web is cut after it has been wound onto a wide roll. The sealing tape must then be unwound from each of the sealing tape rolls produced in the process in order to then be provided with a flexible, film-like coating on at least one side surface.

However, these procedures are relatively complex.

Out of EP 2 990 552 A1 a method for producing a roll of sealing tape is known, in which a first foam strip, which is provided with at least one barrier layer on at least one of its side flanks, is brought together with a second foam strip in such a way that a foam barrier layer web is formed, in which the at least one Barrier layer is arranged between the two foam strips.

The present invention is therefore based on the object of providing a method which makes it possible to produce such sealing tapes in a simpler manner. This object is achieved according to the invention by the subject matter of the independent patent claim.

In a method according to the invention for producing a sealing tape, a foam carrier is first made available and this is transported at least temporarily in a predetermined transport direction. In a further method step, a coating is applied to a first surface of the foam backing. In a further process step, the foam backing is cut into at least two and preferably a large number of strips. At least some of the cut strips are shifted and/or staggered with respect to one another in such a way that their side surfaces, along which the cuts were made, become accessible for the application of the self-adhesive. Furthermore, a self-adhesive is attached to another surface of the individual strips.

In this way it is achieved that each of the cut strips has a coating on one surface and self-adhesive on another surface. These two surfaces are advantageously perpendicular to one another. In a further preferred method, these strips each have a substantially rectangular cross-section.

The coating is preferably built on or attached to the foam carrier without gaps and/or continuously. Said cuts also advantageously extend in a transport direction of the foam carrier. However, it is possible that the foam carrier is at rest when the cuts are made, for example lying on a shelf.

In a further preferred method, the foam carrier extends in the transport direction and in a width direction perpendicular thereto. The Foam carrier extend in said width direction, for example, by one meter.

In a preferred method, the coating is a flexible coating. Advantageously, this is a thin coating. This particularly preferably has a thickness of between 10 μm and 1 mm, preferably between 50 μm and 200 μm. Furthermore, the coating is particularly preferably selected from a group of coatings which contains plastic materials.

In a preferred method, a coating is first applied to the first surface of the foam backing, the foam is then cut, and then the self-adhesive is applied.

However, it would also be conceivable to first apply a self-adhesive, then to cut the foam with the self-adhesive arranged thereon into strips and finally to apply the coating.

In addition, it would also be conceivable to first cut the foam backing into strips and then to apply both the coating and the self-adhesive to it, preferably at the same time.

The advantage of using an elastic and/or flexible foil and/or lamination or coating is that it is easier to apply longitudinal edges of this layer to joint flanks, the so-called flank closure. Depending on the intended application of the sealing tape, the lamination or the coating should meet these requirements. In the case of additional applications, it would also be possible or additionally possible for these coatings to be UV-resistant, waterproof, impervious to driving rain, paintable and/or plasterable.

In a preferred embodiment, the coating is a film coating or film lamination. This coating preferably consists of a plastic which is selected from a group of plastics which contains PU, PP, PE, PVC, PET, TPU and the like. In addition, metallized plastics can also be used.

In addition, it would also be possible to use a metal foil as the coating. In addition, nonwovens could also be used, which could be used with or without impregnation. Finally, elastic membranes such as EPDM foils could also be used. In addition, it would also be conceivable for the coating to be a lamination with a further layer of foam. This further foam can be available in an impregnated or non-impregnated version. A foam can also be selected for this additional foam from a group of foams which contains PU, PP, PE, PVC, TPU, EPDM and the like.

As mentioned above, in addition to lamination with a more or less solid web-like layer, coating with a mass or liquid is also conceivable. In this case, adhesives or sealants could be used, for example, which contain in particular, but not exclusively, silicones, PU, acrylates, hybrid sealants, PVAC and the like. Modifications of these materials could also be used.

In a preferred method, the coating is attached to the foam by means of a foil and in particular a hot-melt foil. It is possible, for example, for an impregnated foam sheet to leave a dryer. A hotmelt film and a coating or laminating film are then unrolled from each supply roll and placed on the foam. This package can then run or be transported through a laminating system with which a predetermined temperature, for example a temperature between 80 and 200 °, preferably between 100 and 180 ° and particularly preferably between 120 and 160 is. The hotmelt film between the foam and the laminating film or the coating melts and in this way the composite of the foam and the film is produced.

In addition, it would also be possible for adhesion to take place using a self-adhesive film or an adhesive mass between a foam material and the film.

In a further method, it is also conceivable that the foam web is coated not just on one side but on both sides, and in particular on two opposite sides. It is then conceivable that this upper and lower side of the preliminary product of the foam web result in an inner and outer side of the sealing tape end product. The advantage of such a double-sided lamination or the application of a coating on both sides could be coatings with different properties specifically tailored to the requirements of the end product. It would be conceivable here, for example, to have a UV-stable coating and a vapor-permeable coating on an outside and, on the other hand, a vapor-tight or vapor-retardant and airtight coating on the inside.

The foam carrier is preferably transported continuously. However, clocked transport would also be conceivable. It is possible that the foam backing itself is stationary while the cuts are being made and instead the cutting blades move and in particular move in a predetermined longitudinal direction of the foam backing and in particular in the direction in which the foam backing would otherwise, i.e. if the cuts are not made , is transported.

The knives can, for example, be rotating knives or knife discs.

In another preferred method, the foam backing is an impregnated foam backing, more preferably a foam backing impregnated for delayed recovery. The foam backing is also advantageously a dried foam backing and particularly preferably a foam backing which has been impregnated and dried prior to processing.

In a preferred method, aqueous dispersions are used as impregnates. Aqueous dispersions with acrylate binders are preferably used. In addition, however, other impregnations could also be used, in particular adhesives or sealants in different liquid media. These adhesives or sealants can be, for example, acrylates, bitumen, polyurethanes, resins and the like.

Water with or without additives or else organic solvents can be considered as liquid media, for example.

The foam carrier can be, for example, a polyurethane foam. This foam preferably has a bulk density of between 5 and 100 kg/m ³ , preferably between 10 and 80 kg/m ³ , preferably between 10 and 60 kg/m ³ , preferably between 15 and 50 kg/m ³ and particularly preferably between 20 and 40 kg/m ³ .

The foam preferably has a compression hardness of between 1 kPa and 8 kPa, preferably between 2 kPa and 6 kPa, preferably between 3 kPa and 4 kPa.

In a preferred embodiment, the air permeability of the foam is between 100 and 10,000 l/m ³ /s, preferably between 200 and 5,000 l/(m ³ *s), preferably between 200 and 2,000 l/(m ³ *s) , preferably between 300 and 900 l/(m ³ *s).

Furthermore, the strips are preferably cut to length. The cutting to length is usually and preferably done as a web, from which the strips - already cut to length - are then cut.

In a preferred method, the first coating is applied to an upward or downward facing surface of the foam backing.

It is also conceivable that the strips are not rotated after cutting. A variant of the method can be used here, in which the self-adhesive is guided laterally to the stiffeners and preferably individual rolls are compressed and rolled up lying flat.

According to the invention, the individual strips are first cut and then preferably shifted relative to one another in a direction perpendicular to the transport direction, so that in particular the side surfaces of these strips are also accessible for the attachment of a self-adhesive. It would be conceivable here for the strips to be offset relative to one another in a vertical direction, for example alternately offset upwards and downwards.

It would also be conceivable for the individual strips to be offset relative to one another in a width direction (likewise perpendicular to the transport seal) and for this also to make the individual side surfaces accessible for the application of the self-adhesive.

In a preferred method, therefore, at least some of the cut strips are shifted relative to one another in such a way that their side faces, in which it is in particular the surfaces along which the cuts have been made that become accessible for the application of the self-adhesive.

With this method, spaces between the individual cut strips could preferably be deliberately created, in which the self-adhesives can be inserted. To insert these self-adhesives, stub shafts could be used, for example, which protrude into these intermediate spaces.

Due to the 90° rotation, several individual rolls can be wound on one shaft with one drive. If the rotation is dispensed with, a stub shaft can preferably be used for each individual roller, with a separate drive for the stub shaft preferably being provided in each case.

In a further preferred method, the cut strips are at least partially rolled up, the strips preferably being compressed in at least one direction during this rolling up.

Advantageously, that surface on which the coating is applied is compressed.

Compression preferably takes place to not less than 20% of the initial height of the foam strip, preferably to not less than 15% of the initial height, preferably to not less than 10% and particularly preferably to not less than 7% of the initial height. The latter means that the foam strip is compressed by 93%.

In a further preferred method, the individual strips are rolled up with respect to a horizontal roll axis.

In a further advantageous method, the strips for applying the self-adhesive are guided onto a self-adhesive tape and, in particular, compressed. In this way, both the application of the self-adhesive and the compression of the foam strips are preferably carried out in a common step.

In a preferred method, the expanded strips pass between two compression rollers. Between these compression rollers, the strips are pressed to an intended degree of compression (e.g. the 11 to 15% mentioned above). A self-adhesive, such as a self-adhesive strip, is fed from a supply roll and adhered and pressed to the compressed foam. This combination is preferably then wound onto a core and secured in compressed form with one or more wraps of adhesive tape.

In principle, it would be possible for the foam web to be cut in a fully expanded state or also in a partially compressed state. In a preferred method, it is conceivable that the laminated web, ie the foam web already provided with the coating, is laid out over a full length (for example 10 m) on a table. Individual strips are then cut from this web. This strip can follow the principle of a bread slicer. The cutting tool, which can be, for example, a circular knife, a saw or an oscillating cutting edge, preferably moves around the workpiece, ie the foam material remains in place. To fix the foam web, slight compression can be carried out using a pressure device, such as a pressure beam or pressure rollers.

The applied coating is preferably airtight. It would also be conceivable that this airtight lamination also makes it possible to fix the foam sheet by means of a vacuum.

It would also be conceivable for several strips to be cut simultaneously using several cutting tools.

In a further preferred procedure, the already coated web is compressed and docked without self-adhesive. In turn, rolls can be cut off in a desired width from this dock. These rolls are preferentially opened by further processing and the belts can expand. The self-adhesive is then applied as described in more detail above.

This procedure results in a considerable simplification of the intermediate storage and transport of the preliminary products.

In a preferred method, the strips are cut in such a way that, in a substantially fully expanded state, the strips have an at least square cross-section, ie a width of the strip is greater than its height. The width indicates the side on the self-adhesive or the side opposite it.

In a further preferred method, it would also be conceivable that the foam web is first cut and then the coating is applied to the individual strips. With this approach, a coating could be applied to the strips prior to compression onto the self-adhesive film. It would also be conceivable that the coating is applied laterally but also above, below or below and above.

As mentioned above, the self-adhesive tape is preferably a double-sided adhesive tape. This double-sided adhesive tape can initially also be equipped with a liner on the side facing away from the foam. In this case it is possible that the combination of the foam backing, the self-adhesive and the liner will roll up.

In a state wound up on the roll, the tape thus has a coating on the outside.

This coating is preferably a film lamination or a sealant.

In a further advantageous method, a coating is applied to a second surface of the foam carrier, this second surface being different from the first surface and in particular being opposite the first surface. In this way, a possibility is created to achieve a targeted control of properties such as diffusion-inhibiting and airtight on the inside, but diffusion-open and driving rain-proof on the outside.

The present disclosure is also directed to a sealing tape made up as a roll of sealing tape, which extends in a first longitudinal direction and in a width direction perpendicular to this first longitudinal direction, this sealing tape having a first surface which extends in this longitudinal direction and the width direction and a second Has surface, which is opposite to the first surface, wherein an adhesive layer is arranged on one of these two surfaces. In addition, the sealing tape has a third surface which extends in the longitudinal direction and in a thickness direction of the tape and a fourth surface which is opposite to the third surface and which also extends in the longitudinal direction and the thickness direction, the third surface or a coating is arranged on the fourth or the third and fourth surface. This is preferably a coating of the type described above.

Furthermore, the sealing strip is preferably manufactured using a method of the type described above (not claimed).

In a further advantageous embodiment (not claimed), the sealing tape is rolled up in a state compressed in the thickness direction. Therefore, preferably the third and fourth surfaces each face outwards or are sides or faces of the roll of sealing tape in the rolled-up state.

Further advantages and embodiments result from the attached drawings:

Show in it:

1

a schematic representation to illustrate a method according to the invention; and

2

a schematic representation of an unrolled sealing tape.

1 shows a schematic representation to illustrate a procedure not according to the invention. In this case, a foam carrier 2 with a surface 2c is transported in a transport direction T in an area B1. This transport direction also corresponds to the longitudinal direction of the sealing tape to be produced later. On the foam backing a coating 14 is applied. This coating 14 can be a surface element which is unwound from a roll. This coating 14 has a surface 14a. In addition, it would also be conceivable to apply a further corresponding coating (not shown) to the surface 2d (not shown) opposite the surface 2c.

In a region B2, a multiplicity of cuts S are made in the foam carrier 2, which has already been provided with the coating 14. These cuts are parallel to one another and also extend in the transport direction T. These cuts produce a multiplicity of strips 22, 24, 26 which are parallel to one another and which extend in the transport direction T.

In a region B3, these individual strips are each rotated counterclockwise by 90°, so that the surfaces provided with the coating 14 each point to the right, viewed in the direction of transport. If corresponding coatings are applied both to the surface 2c and to the opposite surface 2d, a corresponding coating would also be present after the rotation on the left-hand surface viewed in the transport direction.

Finally, in an area B4, an adhesive layer 12 is attached to the underside of the individual cut strips. It is possible that the strips (not shown) are already compressed onto these adhesive layers. The individual sealing tapes are then rolled up (not shown) onto a sealing tape roll 20. Reference numerals 22b and 24b identify two surfaces on which the coating is arranged.

2 shows a schematic representation of a sealing tape 1 in an unrolled state. This sealing strip has a longitudinal direction L, as well as a width direction B perpendicular to this longitudinal direction L and a thickness direction D. Reference number 2c refers to a surface of the sealing strip on which a coating 14 is arranged. A coating could also be arranged on the rear surface 2d. The coating 14 on the side surface 2c and the optionally present coating on the side surface 2d preferably differ from one another in at least one physical property.

Numeral 12 denotes an adhesive layer which is arranged on a downwardly facing surface 2b. The surface 2a is neither coated nor provided with an adhesive layer.

Reference List

1

sealing tape

2

foam backing

2a - 2d

surfaces

12

self-adhesive

14

coating

14a

surface of the coating

20

sealing tape roll

22, 24, 26

stripes

22b, 24b

surfaces

B1 - B4

working area

S

cuts

T

transport direction

B

latitude direction

D

thickness direction

L

direction of length

Claims (8)

1. A method for producing a sealing tape comprising the steps of:

   - providing a foam carrier (2) and transporting it at least temporarily in a predetermined transport direction (T),

   - applying a coating (14) to a first surface (2a) of the foam carrier;

   - cutting said foam carrier into at least two and preferably a plurality of strips (22, 24, 26, 28);

   - displacing and/or offsetting at least some of the cut strips with respect to each other in such a way that their side surfaces along which the cuts have been made become accessible for the application of a self-adhesive;

   - applying a self-adhesive to a further surface (22b, 24b) of the individual strips.
2. The method according to claim 1,
   characterized in that
   the foam carrier (2) is an impregnated foam carrier (2), preferably impregnated for delayed recovery.
3. The method according to at least one of the preceding claims, characterized in that
   the strips (22, 24, 26, 28) are at least partially rolled up, wherein preferably during this rolling-up process the strips (22, 24, 26, 28) being compressed in at least one direction.
4. The method according to at least one of the preceding claims, characterized in that
   the strips are guided to an adhesive tape for applying the self-adhesive.
5. The method according to the preceding claim,
   characterized in that
   the strips are compressed onto a double-sided adhesive tape.
6. The method according to at least one of the preceding claims, characterized in that
   the coating is a film lamination and/or a sealant.
7. The method according to at least one of the preceding claims, characterized in that
   a coating is applied to a second surface (2d) of the foam support (2), wherein this second surface (2d) being different from the first surface (2c) and, in particular, being opposite the first surface (2c).
8. The method according to claim 7,
   characterized in that
   coatings with different properties are applied to the second surface (2d) of the foam carrier (2) and the first surface (2c).

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