Floor covering for covering removable floor panels, floor construction with floor covering, and method for production of the floor covering

Abstract

There is described a floor covering (6) for covering removable floor panels (1), especially of raised floors. To minimize laying costs, there is uniformly applied on the underside of the floor covering (6) a conductive fixing adhesive (2) that has been air-cured to ready-to-lay condition and that is protected externally against drying out by a backing film (7).

Description

[0001] The invention relates to a floor covering, especially for raised floors, according to the preamble of claim 1, as well as to a floor construction comprising removable floor panels covered with the floor covering, according to the preamble of claim 5, and to a method for production of an inventive floor covering, according to the preamble of claim 12.

[0002] Raised or installation floors are used in order to create a second plane that can support foot traffic or other loads above the subfloor of a room. Between the building's subfloor or bare floor and this second plane there is created a clear void space, which can then be used for installation or laying of cables, pipes, air ducts, etc.

[0003] The plane for supporting foot traffic or other loads is very generally constructed from individual, usually square supports or floor panels, which are braced relative to the building floor via a plurality of pedestals or underground structures and on the upper side are lined with floor-covering tiles, which are fixed to the support panels in slip-proof manner by means of fixing adhesive.

[0004] For this purpose it must be ensured that the floor-covering tiles can be removed without problems, in order to permit easy access to the underfloor installation for the purpose of undertaking maintenance tasks. It must therefore be possible to loosen the fixative easily and without destroying it, and so a permanent bond is out of the question.

[0005] Additional requirements are imposed on the fixative, such as provision of a conductive layer, in order thereby to prevent leakage of electrostatic charges that may build up on the surface or to ensure that such charges are conducted to ground.

[0006] Further requirements include ease of laying and good stability of the floor-covering tiles against slipping.

[0007] For this purpose a coat of fixing adhesive, known as a “tackifier”, is commonly applied on the laid base or support panels. An example is Thomsit T425 tackifier of the Henkel Co. or Forbo-Antirutsch 541 [Forbo anti-slip compound 541], on which the floor-covering tiles can be laid without becoming permanently bonded but without danger of slipping after a required setting time of about 30 to 120 minutes has elapsed. The fixing adhesive is based, for example, on an acrylate dispersion, into which an additional conductive additive has been intermixed to ensure the desired conductivity.

[0008] The problems which commonly occur during the laying of floor coverings described in the foregoing can be explained by referring here and now to FIG. 1, which shows a schematic overhead view of a raised floor.

[0009] It is evident that no adhesive is applied in the region of the joints (gap A in FIG. 1) between the support panels. As can be inferred from FIG. 1, it is only in this way that bonding of the support panels to one another can be avoided and the necessary easy access to the underfloor region can be ensured.

[0010] On the whole, therefore, the installation of such a floor is laborious, time-consuming and mistake-prone:

[0011] Once the base construction containing the floor panels has been laid, the fixing adhesive must be applied. In this process, care must be taken that, if at all possible, no adhesive is applied in the region of the abutting joints. On the other hand, sufficient adhesive must be applied in the region of the corners of the base panels, as shown in FIG. 1, in order to fix the floor-covering tiles adequately and to provide a continuous, conductive layer.

[0012] Thereafter the applied coat of fixing adhesive must be hardened or set; during this period, further processing is not possible. The necessary hardening time depends on ambient conditions such as atmospheric humidity, temperature, surface of the floor panels, etc. and is therefore difficult to determine. Thus an unnecessary waste of time can result if the adhesive has already set, or—which is a much worse problem—the floor-covering tiles have become undesirably bonded to the support panels of the floor, so that the floor-covering tiles can no longer be lifted up thereafter without damaging them.

[0013] Finally, the floor-covering tiles must be laid without destroying the fixative and conductive layer, for example by excessive foot traffic. Thus the floor-covering tiles must be laid on the slip-proof adhesive, which can be achieved only with the skill of a craftsman.

[0014] Because of the difficulties outlined in the foregoing, the entire laying process must therefore be performed manually by appropriately trained, skilled craftsmen, thus leading to high costs.

[0015] Starting from this problem, the object is therefore to provide an appropriately pretreated floor covering, whereby the floor-covering laying procedure can be streamlined and the particularly time-consuming and mistake-prone process step of applying the adhesive or tackifier can be separated out from the laying process to be performed manually and achieved in a single process that can be performed externally and in advance by machinery, so that the floor can be installed inexpensively and precisely on the whole, even by less well trained personnel.

[0016] This object is achieved for the floor covering by the features of claim 1, for the overall floor construction by the features of claim 5, and for the method for production of the inventive floor covering by the features of claim 12, in the form of an individual process separated out from the laying process.

[0017] By means of a floor covering pretreated according to the invention with antistatic fixing adhesive applied in ready-to-lay condition on its underside, it is possible to achieve a considerable increase in efficiency during installation of an inventive floor. The adhesive coat is applied on a floor covering according to claim 1 and then allowed to set such that it can be laid without the development of forces of cohesion and without bonding. In addition, it is protected by a film, so that excessive drying out of the conductive or antistatic fixing adhesive is prevented and the desired adhesive effect is preserved until the floor-covering tiles have been laid.

[0018] A requirement often imposed on a floor, namely that the development of electrostatic charges due to friction on a floor acting as an insulating layer be prevented, or that such an effect be compensated by grounding via the floor, can be met in simple manner according to claim 2 by using a tackifier with antistatic effect, obtained from an acrylate dispersion providing the desired adhesive functionality and an intermixed electrically conductive additive.

[0019] A satisfactory antistatic effect is achieved, for example, with carbon, in the form of carbon black, for example, intermixed as an electrically conductive additive in a proportion of about 25% in the tackifier based on an acrylate dispersion. Obviously other substances or substance mixtures having the desired adhesive and/or antistatic properties can be used in the scope of the invention.

[0020] A special additional advantage of the invention is achieved when retrofit operations such as the laying of cable runs are undertaken in the floor under the floor panels. In such a case the floor covering must be lifted off and the floor-covering panels removed and stacked off to the side. Heretofore the electricians have usually walked on the bare floor while performing laying tasks, thus inevitably picking up dust on the soles of their shoes and tracking it onto the exposed adhesive surface when they step out of the duct. This problem is effectively eliminated with the inventive structure of the floor covering. Because, according to the invention, the floor panels are no longer treated with adhesive, they can be simply vacuumed on completion of the retrofit or modification tasks. The undamaged floor covering, for example in the form of covering tiles with underside coating, can be relaid without impairment of their function.

[0021] Finally, a further advantage of the invention becomes clear when the floor covering has to be replaced. Because, according to the invention, the floor covering is not permanently bonded to the base course, such as floor topping, no part of the base course, such as floor topping, is torn up during replacement of the covering, and so there is effectively no need for troweling work. Furthermore, no residual adhesives, which heretofore had to be ground off, are left there. This opens up the opportunity to use the inventive technique with all its advantages even when floor coverings sold by the meter are being laid.

[0022] Furthermore, the inventive floor covering can be produced in a simple method according to claim 12. Because the environmental parameters are adjustable, the setting time of the applied tackifier coat can be precisely maintained and its coat thickness can be kept constant at the optimal value, so that the desired functionality of the adhesive coat as a tackifier but not as a bonding agent is achieved with great reliability. The method can also be performed as a continuous process, thus allowing further cost reductions to be achieved.

[0023] The floor covering according to claim 1 offers the further advantage that, when packaged according to claim 13 in the form of rolls according to claim 3, it is suitable both for direct laying in hand-cut sections and as a commercial precursor product, which can be the starting material for other commercial products in the form of variously sized floor-covering tiles according to claim 4, without the need for changeover times on appropriate machines during its production. Thus, from the floor covering, which can also be sold by the meter, ready-to-lay floor-covering tiles according to claim 4 can be produced by a single operation, in which the floor covering is divided in a manner to be adjusted to the desired tile size, or floor-covering tiles are stamped out from the floor covering by the method the according to claim 14.

[0024] Furthermore, there is no longer any need to take special care with the butt joints of the floor layout or of the laid floor panels during laying of the inventive floor covering or floor-covering tiles, since the adhesive or tackifier is largely hardened or set. The risk of bonding of the base panels of the floor to one another is therefore effectively ruled out, and the function of an inventive floor construction, especially of a raised floor according to claim 5, in order to provide an installation space that is rapidly accessible but concealed from view, can be achieved with great reliability and little time expenditure.

[0025] Furthermore, better adhesion of the floor covering to the floor panels is also achieved in this way, since the floor covering is uniformly coated with tackifier. Thus adhesion of the floor covering to the floor panels is ensured even in the regions of the butt joints of the base panels, without the risk that the floor panels will become bonded to one another, since the fixing adhesive has already set by the time of the laying operation.

[0026] Particularly good adhesion is achieved when the floor covering according to claim 6 is laid in such a way that it overlaps the butt joints of the base panels. This is achieved in a particularly simple way when, according to claim 7, its size is different from that of the floor panels.

[0027] According to claim 8, the fixing-adhesive coat continues to adhere to the floor covering and is not transferred to the floor panels when the floor covering is lifted up to gain access to the underfloor. Specifically, the fixative coat bonds to the floor covering during the inventive production method and must have a natural cohesion that is stronger than the force of adhesion between the adhesive coat and the floor panels.

[0028] This can be accompanied by measures such as provision of a smooth surface according to claim 9 or of an appropriate upper-side coating according to claim 10 or of impregnation of the floor panels according to claim 11.

[0029] The individual features of the embodiments according to the claims can be combined as desired if it seems technically practical.

[0030] Preferred embodiments of the invention will be explained in more detail hereinafter on the basis of schematic drawings, wherein:

[0031] FIG. 1 shows a schematic overhead view of a conventional raised floor during the laying operation, FIG. 2a shows a sectional side view of a conventional raised floor with applied fixing adhesive, but without floor covering, FIG. 2b shows a sectional side view of an inventive raised floor,

[0032] FIG. 3 shows a sectional side view of an inventive floor covering,

[0033] FIG. 4 shows a perspective view of an inventive floor-covering roll,

[0034] FIG. 5 shows a schematic view of an inventive raised floor.

[0035] The procedure for laying of conventional floor-covering tiles on a floor panel forming a raised-floor plane is evident in FIG. 1. A coat of fixing adhesive is applied on floor panels disposed flush with one another along corresponding butt joints 3 and resting via their respective corners on one quarter of the surface of round pedestal heads. Region A along butt joints 3 is left clear, but fixing adhesive is again applied at the corners of the panels. Some floor-covering tiles that have already been laid are indicated by hatched areas.

[0036] FIG. 2a shows a section of a conventional raised floor while the tackifier is setting. A pedestal head 4 is seated on a pedestal 5. Floor panels 1 rest via their respective corners on pedestal head 4. Between panels 1 there are disposed joints 3, in the area of which (see gap A) no adhesive 2 is applied, in contrast to the rest of the upper side of the floor panels. After hardening or setting of the adhesive, conventional floor-covering tiles can be applied thereon.

[0037] In contrast to this, in the section of an inventive raised floor shown in FIG. 2b, floor covering 6 with fixing adhesive 2 applied on its underside is already laid on floor panels 1, and so joints 3 are also overlapped with adhesive coat 2. The floor panels are braced via pedestal heads 4, to the underside of which there are joined pedestals 5. In this way a rapidly accessible clear void space for ventilation shafts, network installations, etc. is provided underneath the floor panels.

[0038] As covering for the floor panels there is used floor covering 6, which is illustrated in FIG. 3 and which has a continuously applied adhesive coat 7 protected by a film 7 that can be easily peeled off.

[0039] FIG. 4 shows a floor covering 6 rolled up as a roll 6b ready for retail. Floor-covering tiles 6a to be punched out are also indicated by broken lines on a portion that has now been unrolled.

[0040] For comparison with the conventionally laid raised floor shown in overhead view in FIG. 1, there is shown in FIG. 5 a raised floor installed using inventive floor-covering tiles 6b (indicated by dot-dash lines): The pedestal heads denoted by 4 support floor panels 1, on which there are fixed floor-covering tiles 6b with fixing adhesive 7 applied flatly on the underside thereof (see FIGS. 2b, 3). By means of broken lines there is also shown a ventilation shaft 11, which runs in the void space between the plane of the floor panels and the plane of the base floor (such as the concrete slab) and is supposed to be kept accessible. It is also evident that floor-covering tiles 6b have a size which is different from (larger than) that of floor panels 1, thus largely ensuring that joints 3 between floor-covering panels 1 are overlapped by floor-covering tiles 6a.

[0041] Modifications of the illustrated versions are obviously possible without going beyond the basic ideas of the invention. From the foregoing description it follows that the floor covering, such as the floor-covering tiles, does not have to be cut to match the pattern in which the floor panels are laid. In other words, the pattern of the raised-floor panels can be, but is not required to be, identical to that of the coated floor-covering tiles.

Claims

1. A floor covering (6) for covering removable floor panels (1), especially of raised floors, characterized in that there is uniformly applied on the underside of the floor covering (6) a conductive fixing adhesive (2) that has been air-cured to ready-to-lay condition and that is protected externally against drying out by a backing film (7).

2. A floor covering (6) according to claim 2, characterized in that an acrylate dispersion containing an electrically conductive additive is used as the fixing adhesive (7).

3. A floor covering (6) according to claim 1 or 2, in the form of a floor-covering roll (6a).

4. A floor covering (6) according to one of claims 1 to 3, in the form of floor-covering tiles (6b).

5. A floor construction, especially a raised floor, in which a floor covering (6) according to one of claims 1 to 4 is laid on a layer of floor panels (1) disposed flush with one another.

6. A floor construction according to claim 5, characterized in that the floor covering (6) overlaps the butt joints (3) between the floor panels (1) laid flush with one another.

7. A floor construction according to claim 5 or 6 with floor-covering tiles (6b) according to claim 3, characterized in that the floor covering (6b) has a size different from that of the floor panels (1).

8. A floor construction according to one of claims 5 to 7, characterized in that the adhesion of the fixing adhesive (2) to the floor covering (6) is stronger than to the floor panels (1).

9. A floor construction according to one of claims 5 to 8, characterized in that the floor panels (1) are finished with a smooth surface on the upper side.

10. A floor construction according to one of claims 5 to 9, characterized in that the floor panels (1) are finished with a smooth coating on the upper side.

11. A floor construction according to one of claims 5 to 10, characterized in that the floor panels (l) are finished with an impregnation on the upper side.

12. A method for production of a floor covering (6) according to one of claims 1 to 3, characterized in that it comprises the following process steps:

application of a conductive fixing adhesive (2) onto the floor covering (6),

air-curing of the floor covering (6) provided with the conductive fixing adhesive (2), the air-curing time (TL) being chosen such that the adhesive (2) sets sufficiently that the natural cohesion is stronger than the force of adhesion to a backing film (7) to be subsequently applied,

protection of the conductive fixing adhesive (2) with the backing film (7), which can be peeled off without residues.

13. A method according to claim 12 for production of a floor covering (6) according to claim 3, characterized in that the floor covering (6) is then rolled up and packaged as commercial floor-covering rolls (6a).

14. A method according to claim 12 for production of a floor covering (6) according to claim 4, characterized in that the floor-covering tiles (6b) are subsequently punched out of the floor covering (6).