Method for producing a decorated wall or floor panel

Abstract

A method for producing a decorated wall or floor panel, comprises the steps of: providing a pourable carrier material, in particular a granulate; placing the carrier material between two belt-like conveying means; forming the carrier material under the influence of temperature to form a web-shaped carrier; compressing the carrier; treating the carrier under the influence of pressure with use of a twin belt press at a first temperature T1 while forming a first compression factor K1 of the carrier; treating the carrier under the influence of pressure at a second temperature T2 while forming a second compression factor K2 of the carrier, wherein T2<T1 and wherein K2<K1; optionally cooling the carrier; optionally applying a decorative subsurface onto at least part of the carrier; applying a decorative template onto at least part of the carrier; and applying a protective layer onto at least part of the decoration.

Claims

1. A method for producing a decorated wall or floor panel, comprising the method steps: a) providing a pourable carrier material; b) placing the carrier material between two belt conveying means; c) forming the carrier material under the action of temperature while forming a carrier sheet; d) compressing the carrier; e) treating the carrier under the action of pressure by use of a twin belt press at a temperature T1 while reducing the thickness of the carrier by compression factor K1; f) subsequently treating the carrier under the action of pressure at a temperature T2 while reducing the thickness of the carrier by a compression factor K2, wherein T2<T1, and wherein K2<K1, wherein T1 is in a range of between 150 C. and 190 C., T2 is in a range between 100 C. and 150 C., K1 is in a range between >0 and 0.3, and K2 is in a range between >0 and 0.2; g) optionally cooling the carrier; h) optionally applying a decorative subsurface onto at least a portion of the carrier; i) applying a decoration reproducing a decorative template onto at least a portion of the carrier; and j) applying a protective layer onto at least a portion of the decoration.

2. The method according to claim 1, wherein the temperature T1 and the temperature T2 are set by tempering means acting separate from each other.

3. The method according to claim 1, wherein the method steps e) and f) are carried out in a common twin belt press.

4. The method according to claim 1, wherein the method steps e) and f) are carried out in two pressing means separated from each other.

5. The method according to claim 4, wherein the method step f) is carried out in a twin belt press or in a calender.

6. The method according to claim 1, wherein a carrier material based on a plastic or a wood-plastic composite material is provided.

7. The method according to claim 1, wherein the carrier is temporarily stored between method steps e) and f).

8. The method according to claim 1, wherein the carrier is cooled down to a temperature T3 between method steps e) and f), wherein T3<T1 and wherein T3<T2.

9. The method according to claim 1, wherein the carrier prior or subsequently to method step f) is heated to a temperature which is above the crystallization temperature of a plastic component present in the carrier.

10. The method according to claim 1, wherein prior to method step e) an anti-adhesive means is disposed such that at least within the twin belt press it is disposed between the carrier and the conveying means.

11. The method according to claim 1, wherein the carrier is cooled prior to method step e) in particular below the melting point or the softening point of a plastic component of the carrier.

12. The method according to claim 1, wherein the carrier subsequently to method step f) is heated to a temperature above the crystallization temperature of a plastic present in the carrier.

13. The method according to claim 1, wherein method step f) is carried out in a twin belt press, wherein belt conveying means used in method step f) each comprise a steel belt coated with polytetrafluoroethylene.

14. The method according to claim 1, wherein a method step d) is carried out by use of an S-roller.

15. An apparatus for carrying out a method according to claim 1, comprising; two endless belt conveying means; a discharge unit for applying a carrier material between the belt conveying means; a molding unit for forming a carrier sheet from the carrier material; a first pressing means for compressing the carrier; a twin belt press as a pressing means for treating the carrier under the action of pressure at a temperature T1; optionally a further pressing means, wherein the apparatus is further configured such that the carrier after the treatment in the twin belt under the action of pressure at a temperature T1 can be treated further at a temperature T2 in the twin belt press or in the further pressing means such that a compression factor K1 can be set at the temperature T1 and a compression factor K2 can be set at the temperature T2, wherein K2<K1, wherein T1 can be set in a range of between 150 C. and 190 C., T2 can be set in a range between 100 C. and 150 C., K1 can be set in a range between >0 and 0.3, and K2 can be set in a range between >0 and 0.2.

Description

DRAWINGS

(1) The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

(2) FIG. 1 schematically shows an embodiment of an apparatus according to the disclosure for carrying out a part of the method according to the invention;

(3) FIG. 2 schematically shows an embodiment of a further apparatus according to the disclosure for carrying out a part of the method according to the disclosure; and

(4) FIG. 3 shows an exemplary S-roller for carrying out a method step of the method according to the disclosure.

(5) Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

(6) Example embodiments will now be described more fully with reference to the accompanying drawings.

(7) The apparatus according to FIG. 1 is suitable for a method for producing a decorated wall or floor panel. Here, with respect to FIG. 1 in particular processing stations for the following method steps are described: a) providing a pourable carrier material 20, in particular granules; b) arranging the carrier material 20 between two belt-like conveying means 12, 14; c) molding the carrier material 20 under the influence of temperature while forming a web-shaped carrier 36; d) compressing the carrier 36; e) treating the carrier 36 under the action of pressure by use of a twin belt press, wherein the carrier is cooled prior to or within the twin belt press at a temperature T1 while forming a compression factor K1 of the carrier; f) treating the carrier 36 under the action of pressure at a temperature T2 while forming a compression factor K2 of the carrier 36, wherein T2<T1 and wherein K2<K1; g) cooling the carrier 36, if necessary.

(8) Following these method steps the method may comprise further method steps in order to obtain the finished wall or floor panel.

(9) The apparatus 10 according to FIG. 1 comprises two endless belt-like conveying means 12, 14, which are guided in particular by deflection rollers 16 in such a way that between them a receiving space 18 or processing gap for receiving and processing a provided pourable, in particular granular carrier material 20, for example on the basis of a plastic, e.g. PVC, or a wood-plastic composite material, e.g. wood and PP, PE or a block copolymer comprising PP and PE or based on an HDF material based on PVC is formed. The conveying means 12, 14 can be at least partially made of polytetrafluoroethylene, for example coated therewith. Moreover, the conveying means 12, 14 can at least partially be roughened or structured in particular on their side facing the receiving space 18. Moreover, the conveying means 12, 14 may have a width in a range of about 1.5 m.

(10) In order to apply the carrier material 20 between the belt-like conveying means 12, 14 or in the receiving space 18, a discharge unit 22 with one or a plurality of discharge heads 24 is provided, by means of which the carrier material 20 can be placed on the lower conveying means 14. The discharge heads 24 can comprise a funnel 25 which applies the carrier material 20 onto corresponding scattering rollers 26, whereupon the carrier material 20 can be scattered onto the lower conveying means 14.

(11) In order to ensure a homogeneous application of the carrier material 20 onto the lower conveying means 14 a sensor for checking the placement of the carrier material 20 between two belt-like conveying means 12, 14 may be provided. The sensor can in particular be coupled with the discharge unit 22 in order to avoid a potentially inaccurate filling of the accommodating space 18.

(12) In order to enable a particularly homogeneous distribution of the carrier material 20, vibrators may be provided. These may, for example, act on the lower conveying means 14 and may be arranged, for example, below the lower conveying means 14, such that the carrier material 20 is finely distributed.

(13) In order to prevent unwanted contamination and a damage of downstream processing stations, moreover a sensor for detecting metals can be provided, which is able to detect inadvertently introduced metal.

(14) Furthermore, a device for introducing a fiber material into the receiving space 18 and thus into the carrier may be provided. For example, the fiber material may be configured band-like and be unwound from a roll. Herein, the fiber material can be disposed between two discharge heads 24 in order to be able to dispose different materials above and below the fiber material. Thus, the fiber material can be introduced, for example, in such a way that above and below the fiber material a desired quantity of carrier material 20 is disposed.

(15) In the conveying direction of the conveying means 12, 14, which is indicated by the arrow 13, a molding unit 28 is provided which is configured to mold the carrier material 20 under the action of temperature or heat in order to melt the carrier material 20 while forming a web-shaped or web-like carrier 36. For this purpose, the molding unit 28 may comprise two plate-like molding means 30, 32 which can be heated by one or two heaters 34, for example by means of a thermal oil. In this way the carrier material 20 can be heated until, depending on the melting point of the carrier material 20 or a portion thereof, it has reached a temperature of, for example, 180 C. to 200 C. depending on the material used, such as PVC or a WPV material. For this purpose, the molding unit 28 or the molding means 30, 32 can, for example, be heated to a temperature of up to 250 C. In this case, for example, one or, for setting a temperature gradient, a plurality of independently adjustable heating areas may be provided. For example, the entire molding means 30, 32 which may have a length of several meters, may be heatable, or only a portion thereof may be heatable.

(16) Furthermore, the molding unit 28 can, in particular, comprise a parallel gap, which may be formed by the plate-like molding means 30, 32. Herein, however, at the inlet an inlet channel may be provided in a conical shape in order to enable an improved inflow of the carrier material 20. The force acting on the carrier material 20 can be in a range of >0 kg/m.sup.2 to 1 kg/m.sup.2. In particular, a uniform pressurization without the provision of a pressure profile or a pressure gradient may be provided.

(17) Furthermore, it can be seen in FIG. 1 that the lower molding means 32 is longer than the upper molding means 30 and also starts upstream of the upper one. As a result, it can be achieved that a processing is not carried out until the carrier material 20 and optionally the film material is already melted or at least partially melted and at least partially softened. As a result, a particularly defined molding process can be achieved.

(18) In the further course in the conveying direction of the conveying units 12, 14, the web-like carrier 36 is fed through a pressing means 38. The pressing means 38 can, for example, include an S-roller, which is shown in detail in FIG. 3. The S-roller may be displaceable substantially perpendicular to the surface of the carrier 36 and thus to the direction of displacement of the carrier 36, as indicated by the arrow 58, so that the desired pressures can be particularly advantageously be adjustable. Furthermore, the pressing means 38 can for example apply a pressure onto the carrier 36 in a range of 1 kg/m.sup.2 to 3 kg/m.sup.2. The S-roller comprises a main roller 60 which acts on the web-shaped carrier 36. Here the belt tension may be sufficient as counter-pressure, however, it is preferred that at least one counter-pressure roller 62 is provided. For a suitable guidance of the web-like carrier 36, moreover, two pairs of calender rollers 64 and optionally deflection rollers 66 may be provided which may provide a suitable belt tension. In FIG. 2 it can be seen that the web-like carrier 36 is fed twice in an S-shaped manner around the deflection rollers 66 and the main roller 60, and it is this type of guidance that specifies the term S-roller. In detail, the main roller 60 can be wrapped by the web-shaped carrier 36 in a range of approximately 50% or more. The temperature of the carrier 36 at the entry into the pressing means 38 corresponds in particular to the temperature present at the exit from the molding unit 28.

(19) Irrespective of the specific embodiment of the pressing means 38 or the apparatus 10 the pressing means 38 can be operated at a temperature which is in a range from 130 C. to 200 C., approximately in a range from 160 C. to 200 C., for example 180 C.

(20) From the pressing means 38 the carrier 36 is subsequently fed to a further pressing means 40. In order to compensate any heat loss of the carrier 36 or to intentionally heat the carrier 36 further or to actively cool the carrier 36 a further tempering means 42 such as a heating means, for example an IR heater, or preferably a cooling means for cooling the carrier 36 can be arranged between the pressing means 38, 40. Herein, the carrier 36 can also be cooled by a heating means provided that it transmits a temperature to the carrier which is below the carrier temperature present before the entry into the tempering means 42, but above room temperature.

(21) Returning to the pressing means 40, this can advantageously be a twin belt press which in particular may comprise belts 44, 46, such as steel belts or else plastic belts which, for example, may be coated with polytetrafluoroethylene (Teflon) on the side facing the carrier 36, and wherein the belts 44, 46 of the twin belt press may be guided by deflection rollers 48, 50. The deflection rollers 48, 50 can, for example, be heated or advantageously cooled, for example by means of a thermal oil tempering and/or the rollers on the same side of the gap may be disposed at a distance in a range from 1 m to 2 m, for example 1.5 m, from each other, wherein the belts 44, 46 may have a width in a range of about 1.5 m. According to FIG. 1, the carrier 36 disposed between the conveying means 12, 14 is guided between the deflection rollers 48, 50 and thus between the belts 44, 46, such as in particular steel belts. On the side of the belts 44, 46 opposite to the carrier 36 respective pressing and/or tempering means 52, 54 are provided by means of which the carrier 36 can be cooled and, if necessary, heated. These can heat, cool and slightly compress the conveying means 12, 14 and thus the carrier 36. For this purpose, for example, an air cooling system may be provided and a plurality of rollers which can allow intermittent pressing.

(22) The tempering means 52, 54 can set a temperature T1 of the carrier 36 which is in the range from 150 C. to 190 C., for example from 160 C. to 180 C., such as 170 C. At a corresponding pressing pressure, thus, a compression factor K1 of the carrier in a range of 0.1 to 0.3, for example 0.15 to 0.25, is achieved such that the thickness at the abovementioned compression factors, for example, decreases by a value which is in a range of 10% to 30%, in particular 15% to 25%, such as 20%.

(23) Furthermore, the further tempering means 55, 57 can set a temperature T2 of the carrier 36 which is in a range of 100 C. to 150 C., such as 120 C. At a corresponding pressing pressure, thus, a compression factor K2 of the carrier in a range of >0 to 0.2, for example >0.03 to 0.15, such as 0.05 to 0.12, exemplarily at 0.1, is achieved such that the thickness at the abovementioned compression factors, for example, decreases by a value which is in a range of 3% to 15%, in particular 5% to 12%, such as 10%.

(24) The tempering means 52, 54, 55, 57 for setting the temperature T1 and/or T2 can, for example, be designed as NIR radiators or can be fed by or comprise a heating circuit.

(25) This allows different temperature zones to be set in the twin belt press such that the carrier 36 is first compressed at the temperature T1 with a compression factor K1, and wherein the carrier 36 is further compressed at the temperature T2 with a compression factor K2, wherein K1<K2. As a result, the surface of the carrier, in particular the upper surface, is substantially not significantly compressed but rather smoothed.

(26) The same can be realized, as shown in FIG. 2, by providing a further pressing unit 49 in the advancing direction of the carrier 36. For this purpose, a further twin belt press can be provided, or, as shown in FIG. 2, a calender with the calender rollers 51, 53 may be provided in order to smoothen the carrier 36 or its surface.

(27) A cooling means 56 can be arranged downstream of the pressing means 40 in the conveying direction by means of which the carrier 36 can be cooled down to a temperature in a range of 350 C. In this case, the cooling means 56 can, for example, be based on water cooling and may have several cooling zones in order to enable a defined cooling by use of precisely adaptable cooling programs. The length of the cooling zone may correspond to the effective length of the pressing means 40. Downstream of the cooling means 56 there may be provided yet another cooling belt.

(28) Following these method steps the carrier 36 which may have a final thickness in a range from 3 mm to 5 mm, such as 4.1 mm, can immediately be further treated or stored, for example as a web-shaped carrier 36 or as an already separated plate-shaped carrier.

(29) Furthermore, in the traveling direction of the carrier 36 downstream of the rolls 16 at least one heating means 59 or two heating means 59 can be provided which may be arranged above and possibly below the carrier 36 and by means of which the carrier 36 can be heated. As a result, it is possible to heat the carrier 36 after method step f) to a temperature which is above the crystallization temperature of a plastic component included in the carrier 36, wherein a cooling process may follow.

(30) For example following the processings in the pressing means 40 or the heating means 57 the further method steps are carried out in the method according to the disclosure: g) optionally applying a decorative subsurface onto at least a portion of the carrier 36; h) applying a decoration reproducing a decorative template onto at least a portion of the carrier 36; i) applying a protective layer onto at least a portion of the decoration; j) optionally structuring the protective layer; and k) optionally treating the carrier 36 for electrostatic discharge prior to one of the abovementioned method steps.

(31) The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.