Method and device for manufacturing products having a surface provided with embossments, and products obtained thereby

Abstract

A method for manufacturing a product having a surface provided with embossments, includes bringing a material web is in contact with a roller. The roller is provided with a relief at its surface, with which, via this relief, embossments are formed in the material web. The roller has a circumference of which, or at least certain parts thereof that are variable, or alternatively the circumference of the roller is variable by making use of embossing elements, wherein the mutual angular position thereof is adjustable.

Claims

1. A method for manufacturing a product having a surface provided with embossments, comprising the steps of: bringing a material web into contact with a roller, the roller having a variable circumference and a relief at a surface of the roller; forming one of the embossments in the material web by the relief of the roller; placing the embossment in register with a printed motif present on the material web; automatically adjusting a position of the relief in respect to the printed motif by varying the variable circumference; wherein the roller has at least first and second segment-shaped embossing elements, arranged along the variable circumference thereof and defining the relief, at least first and second intermediate spaces disposed about the variable circumference between the at least first and second segment-shaped embossing elements; wherein the at least first and second segment-shaped embossing elements are automatically angularly adjusted relative to one another by rotating one of the at least first and second segment-shaped embossing elements relative to another one of the at least first and second segment-shaped embossing elements about an axis of the roller according to the printed motif, said at least first and second intermediate spaces defining distances relative to one another according to an angular adjustment of the at least first and second segment-shaped embossing elements; wherein the angular adjustment of the first segment-shaped embossing element includes the step of rotating the first segment-shaped embossing element about the axis such that a first end of the first segment-shaped embossing element is closer to a second end of the second segment-shaped embossing element than a second end of the first segment-shaped embossing element to a first end of the second segment-shaped embossing element.

2. The method of claim 1, wherein in a first condition the at least first and second intermediate spaces have generally a same value, wherein in a second condition such that the first segment-shaped embossing element is angularly adjusted about the axis at a first angle relative to the second segment-shaped embossing element, the at least first and second intermediate spaces have different values.

3. The method of claim 1, comprising the step of performing the angular adjustment by detection of the printed motif.

4. The method of claim 1, further comprising the step of bending the material web around the roller, such that cooperation between the relief and the material web is over an arc-shaped profile.

5. The method of claim 1, wherein the at least first and second segment-shaped embossing elements each define an arc-shape.

6. The method of claim 5, wherein the at least first and second segment-shaped embossing elements have a same shape and a same length.

7. The method of claim 5, wherein the at least first and second segment-shaped embossing elements are arranged diagonally opposite one another.

8. The method of claim 5, wherein the at least first and second segment-shaped embossing elements are each driven by a separate motor and correspondingly rotated about the axis relative to one another.

9. The method of claim 1, further comprising the step of supplying the material web, or at least a surface thereof to be provided with the embossments, to the roller in a heated condition, and arranging the roller in a cooled condition.

10. The method of claim 1, wherein the material web comprises synthetic material.

11. The method of claim 1, wherein the material web comprises a continuous material web, which, after providing the embossments, the method further comprises the step of cutting the continuous web into floor panels.

12. The method of claim 1, wherein the angular adjustment of each of the at least first and second segment-shaped embossing elements is realized by a drive system integrated in the roller and controlled automatically on the basis of feed forward or feedback of the material web.

13. The method of claim 12, wherein a sensor or a detection mechanism acts on a location of the printed motif after which the variable circumference of the roller is adjusted as a function of detection by the sensor or the detection mechanism and by the drive system.

14. The method of claim 1, wherein the first intermediate space is defined between the first end of the first segment-shaped embossing element and the second end of the second segment-shaped embossing element, and the second intermediate space is defined between the second end of the first segment-shaped embossing element and the first end of the second segment-shaped embossing element, the first intermediate space having a shorter length than the second intermediate space.

15. A method for manufacturing a product having a surface provided with embossments, comprising the steps of: bringing a material web into contact with a roller, the roller having a variable circumference and a relief at a surface of the roller; forming one of the embossments in the material web by the relief of the roller; placing the embossment in register with a printed motif present on the material web; automatically adjusting a position of the relief in respect to the printed motif by varying the variable circumference; wherein the roller has at least first and second segment-shaped embossing elements, arranged along the variable circumference thereof and defining the relief, at least first and second intermediate spaces disposed about the variable circumference between the at least first and second segment-shaped embossing elements; wherein the first and second segment-shaped embossing elements are automatically angularly adjusted relative to one another by rotating one of the at least first and second segment-shaped embossing elements relative to another one of the at least first and second segment-shaped embossing elements about an axis of the roller according to the printed motif, said at least first and second intermediate spaces defining distances relative to one another according to an angular adjustment of the at least first and second segment-shaped embossing elements; wherein in a first condition the at least first and second intermediate spaces have generally a same value, wherein in a second condition such that the first segment-shaped embossing element is angularly adjusted about the axis at a first angle relative to the second segment-shaped embossing element, the at least first and second intermediate spaces have different values; wherein the at least first and second segment-shaped embossing elements each define an arc-shape.

16. The method of claim 15, wherein the at least first and second segment-shaped embossing elements have a same shape and a same length.

17. The method of claim 15, further comprising the step of supplying the material web, or at least a surface thereof to be provided with the embossments, to the roller in a heated condition, and arranging the roller in a cooled condition.

18. The method of claim 15, wherein the angular adjustment of the first segment-shaped embossing element includes the step of rotating the first segment-shaped embossing element about the axis such that a first end of the first segment-shaped embossing element is closer to a second end of the second segment-shaped embossing element than a second end of the first segment-shaped embossing element to a first end of the second segment-shaped embossing element.

19. A method for manufacturing a product having a surface provided with embossments, comprising the steps of: bringing a material web into contact with a roller, the roller having a variable circumference and a relief at a surface of the roller; forming one of the embossments in the material web by the relief of the roller; placing the embossment in register with a printed motif present on the material web; automatically adjusting a position of the relief in respect to the printed motif by varying the variable circumference; wherein the roller has at least first and second segment-shaped embossing elements, arranged along the variable circumference thereof and defining the relief, at least first and second intermediate spaces disposed about the variable circumference between the at least first and second segment-shaped embossing elements; wherein the first and second segment-shaped embossing elements are automatically angularly adjusted relative to one another by rotating one of the at least first and second segment-shaped embossing elements relative to another one of the at least first and second segment-shaped embossing elements about an axis of the roller according to the printed motif, said at least first and second intermediate spaces defining distances relative to one another according to an angular adjustment of the at least first and second segment-shaped embossing elements; wherein the at least first and second segment-shaped embossing elements each define an arc-shape; wherein the first intermediate space is defined between the first end of the first segment-shaped embossing element and the second end of the second segment-shaped embossing element, and the second intermediate space is defined between the second end of the first segment-shaped embossing element and the first end of the second segment-shaped embossing element, the first intermediate space having a shorter length than the second intermediate space.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) With the intention of better showing the characteristics of the invention, herein after, as an example without any limitative character, some preferred embodiments are described, with reference to the accompanying drawings, wherein:

(2) FIG. 1 schematically represents an embodiment of the method according to the invention, as well as schematically illustrates a device according to the invention applied for this purpose;

(3) FIG. 2 represents a variant to the embodiment of the roller;

(4) FIGS. 3 and 4 in a schematic manner represent two drive systems which can be applied in a roller according to the first aspect of the invention;

(5) FIG. 5 strongly schematized represents another variant of the embodiment of FIG. 2;

(6) FIGS. 6 and 7 schematically represent two possibilities of embodiments of the second aspect of the invention;

(7) FIGS. 8 to 16 still relate to a number of variants of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(8) In FIG. 1, schematically a method is represented for manufacturing, according to the invention, a product 1 having a surface 3 provided with embossments 2, wherein a material web 4 is brought into contact with a roller 5, which roller 5 is provided with a relief or structure 7 on its surface 6, in other words, a profiled surface, wherein said embossments 2 are formed in the material web 4 via this relief.

(9) In the represented example, the material web consists of a substrate 8 and at least a decor layer 9 which is made as a film and is laminated on the substrate and which comprises a printed motif 10. Moreover, preferably also a transparent wear layer 11 is provided on top of the whole, which wear layer preferably also comprises thermoplastic synthetic material.

(10) Herein, the roller 5 forms the most important part of a processing station 12 for forming the embossments 2. The substrate 8 can be supplied prefabricated from a reel or the like or can also be produced upstream of said processing station 12 in a production unit 13, either by forming the substrate 8 there from a basic material substantially on the basis of synthetic material, for example, synthetic material pellets, or by laminating various prefabricated layers on top of each other, or also by forming a substrate by means of a so-called gelling process. According to variants, other manufacturing techniques for the substrate are not excluded. The printed decor layer 9 and the wear layer 11 are laminated on the substrate and can be supplied from not represented supply reels. Lamination can take place by means of mutual fusion and/or by the intermediary of additionally added substances, such as plastisols, or also in any other manner. In consideration of the fact that various known techniques are possible, providing the decor layer 9 and the wear layer 11 on the substrate is illustrated in a schematic manner only.

(11) The particularity of the invention consists in that for the roller 5, use is made of a roller, of which the circumference, and in this case the length of the circumference, is variable, such that with length variations occurring in the printed motif 10, which means that the distance over which a motif is repeated, will vary, also the average length over which the relief 7 extends per rotation can be adapted, in such a manner that the relief 7, seen on average, remains in register with the passing printed motif 10.

(12) In the example, for this purpose use is made of a plurality, in this case three, of segment-shaped embossing elements or structuring elements 14, which are arranged along the circumference and can be moved radially apart, with the consequence that the total circumference thereof alters in size in that the intermediate spaces T then also change. The radial displacement is indicated by arrows R. This displacement can be realized in any manner and, as schematically represented, is performed by a drive system 15 integrated in the roller 5. This drive system 15 preferably is controlled automatically on the basis of, for example, either a feed forward 16 or a feedback 17. Herein, by means of a sensor or any other detection mechanism, 18 and 19, respectively, a control is performed on the location of the print, possibly by means of marks provided in the decor layer 9, after which the circumference of the roller 5 is adjusted in function hereof and by means of the drive system 15.

(13) As described in the introduction, the material web 4 preferably is bent around the roller 5, such that the cooperation between the relief 7 and the material web 4 is performed at least over an arc-shaped part B, by which a longer contact of preferably at least three seconds is maintained between the surface of the roller and the material web 4.

(14) In the example, the pressing on and bending over the roller 5 is performed by means of a roller 20, preferably with a relatively soft surface, for example, of rubber, and a bending roller 21, which may consist of any material. It is clear that possible other pressing on means can be applied, or also additional pressing on means, such as the represented rollers 22, may be applied.

(15) As mentioned in the introduction, the material web 4 possibly can be supplied to the roller in a more or less heated condition, either with residual heat originating from a preceding manufacturing process, or by preceding heating, whereas the whole is cooled during providing the embossments, preferably via a cooling of the roller 5, in this case by means of a cooling liquid flowing through a cooling circuit 23 of the roller.

(16) Subsequently, the final product possibly may be cut to smaller pieces, such as, for example, LVT tiles 24.

(17) Possibly, a glass fiber reinforcement layer 25 can be incorporated into the substrate.

(18) It is noted that the various layers of the material web 4 are represented schematically. In reality, the layers 9 and 11 are thin films, whereas the substrate 4 determines the fundamental thickness. Backing layers may be applied, too.

(19) In the case of vinyl or the like, the material web 4 preferably has a thickness of 2 to 6 mm.

(20) It is noted that the segment-shaped embossing elements 14 do not necessarily have to be radially displaced in a simultaneous manner, but that they can also be controlled separately, for example, in that each segment, immediately before coming into contact with the material web, is brought into the desired radial position.

(21) It is also clear that the roller 5 preferably is driven by a not represented motor. Also, the rollers 20-21 may or may not be driven.

(22) In FIG. 2, a similar roller 5 is represented schematically, however, having only two instead of three segment-shaped embossing elements 14.

(23) In FIG. 3, a mechanical drive system for displacing the segment-shaped embossing elements 14 is represented schematically, which system consists of lever arms 26 carrying the segment-shaped embossing elements on one extremity 27 and which can be displaced on their other extremities 28 via a spindle system 29. The spindle system is driven via transmission elements 30-31-32 by means of a servo motor 33. The transmission system is illustrated for one embossing element 14 only, however, it is clear that via the same servo motor 33 and respective coupled thereto transmission means a plurality of embossing elements can be driven simultaneously.

(24) Driving the roller 5 is performed by means of the motor 34.

(25) Generally, it can be stated that the above-described rollers 5 can be made with any axial length L. A practical length is from one meter to several meters.

(26) In FIG. 4, a variant is illustrated with conical elements 35 which, by an axial drive and displacement A thereof, provide for a radial displacement R on the embossing elements 14, by working in conjunction with parts 36 thereof.

(27) FIG. 5 shows in a strongly schematized manner that the enlargement of the circumference can also be realized with only one segment-shaped embossing element 14, which, for example, can be pressed open, as schematically represented.

(28) In FIG. 6, the second aspect of the invention is represented schematically, wherein the roller 5 is provided with one replaceable embossing element 14, in this case in the form of a press plate which is tensioned around a basic part 37. In principle, this tensioning can be performed in any manner. A practical possibility consists in that, as schematically illustrated, the press plate, on one extremity, is fixedly hooked in a seat via a formed thereon hook-shaped part 38, and on the other extremity is clamped into a seat by means of another attachment element 39.

(29) FIG. 7 schematically represents another possibility of the second aspect, wherein a plurality of segment-shaped embossing elements 14 are provided on a basic part 37 in an exchangeable manner. In this case, they can be mounted and dismounted, for example, by means of an axial movement over the basic part 37.

(30) It is clear that the first and the second aspect can also be combined, for example, by working in FIGS. 1 through 5 with replaceable embossing elements or partially replaceable embossing elements. So, for example, may parts 40 be used, which form a carrier for parts 41, for example, in the form of a press plate, which latter then function as the actual embossing parts, wherein the parts 41 are replaceable in accordance with the second aspect of the invention.

(31) Also, in respect to the methods as well as in respect to the devices, all herein above-described operations and components pertaining to the first aspect may also be applied in the second aspect and reverse; such in all possible combinations, in as far as such combinations are not contradictory.

(32) In FIGS. 8 and 9, schematically an important variant of the first aspect of the invention is represented, wherein, as aforementioned, an adjustment is provided of the mutual angular position about axis X of the embossing elements 14, in this case arc segment-shaped embossing elements.

(33) In the example of FIGS. 8-9 two approximately half-cylindrical embossing elements 14 are used. In the condition of FIG. 8, those are in positions situated precisely diagonally opposite, with equal intermediate spaces or intermediate distances T1 and T2. If now a larger “repeat” distance is necessary, for example, by a larger stretching, the distance T1 can be enlarged by providing a suitable mutual angular adjustment and, as illustrated in FIG. 9, applying a larger distance T1 before the embossing element, which as next has to be brought into contact with the material web 4, actually contacts the material web. Thus, 14B is adjusted in respect to 14A about the axis X. After then only 14B is in contact with the material web, 14A in its turn can be positioned in respect to 14B in order to then adjust the desired distance T2.

(34) Of course, this all can take place with the necessary controls and in a variety of applications, analogous as herein above described in the introduction or by means of FIGS. 1 to 7.

(35) Each embossing element 14 can be driven by a separate motor, for example, servo motor, and/or be controlled by means of mutual drives. However, other driving systems are not excluded. In consideration of the fact that the drives are of any kind, they are not specifically illustrated in FIGS. 8 and 9 as well as in the FIG. 10 described below.

(36) FIG. 10 shows that the whole can be balanced with counterweights 42A-42B, preferably for each embossing element.

(37) It is clear that in all embodiments the embossing elements 14 can be cooled.

(38) FIGS. 11 to 16 represent, strongly schematized, still a number of other embodiments, wherein use is made of mutually rotatable embossing elements about axis X, herein below also called segments. Herein, three segments are represented; however, other numbers are not excluded, either.

(39) In FIGS. 11 and 12, an embodiment is represented with springs as well as positioning systems, for example, servos or the like, between the segments or embossing elements I-II-III. Possibilities without springs are possible, too, as explained further on. In FIG. 11, servo PA is switched on and positions segment II so far in respect to segment I that the embossments remain in register with the decor. Servos PB and PC are not active and segment III is being centered by means of the springs between the segments I and II. When segment I leaves the material web, as in FIG. 12, servo PA is switched off and segment I centers between II and III. Then servo PB has to be switched on for positioning segment III in respect to II, and so on. Of course, a general drive is there, too.

(40) FIG. 13 makes clear that the centerings and springs are not necessary. One can also work with control means only, such as servos PA-PB-PC or hydraulic positioning systems and the like, which then each have to provide for the appropriate mutual displacements. The general rotational movement has to be performed via, for example, a drive in the region G.

(41) Instead of using a general drive G, separate main drives can be used as well. FIGS. 14 and 15 schematically illustrate an example. Via supports S-I and S-II, the segments or embossing elements I and II are freely rotatable supported on the shaft and each are rotated around the shaft by motors M1 and M2, for example, servo motors. The supports S-III of segment III are fixedly provided on the shaft, which is driven via motor M3. By simultaneously driving the motors M1-M2-M3 and appropriately providing for a mutually advanced or delayed movement, the distance between two segments successively contacting the material web can be set each time.

(42) FIG. 15 is a schematized cross-section according to line XV-XV in FIG. 14. The embossing element III is not represented in FIG. 14, in consideration of the fact that it is situated on the rear side.

(43) FIG. 16 represents a variant with a central shaft, which can be a large hollow shaft which, via a motor M, provides for the general rotation. The segments I-II-III are made as shells, which are mutually displaceable in order to adjust the intermediate space of the shell which then starts contacting the material web and the preceding shell, by means of drives, such as servos PA-PB-PC. This is possible, for example, in that the servos cooperate with a gearwheel TA, which cooperation determines the position of each segment in respect to the shaft.

(44) It is clear that said segments I-II-III form the herein above-mentioned embossing elements 14.

(45) It is noted that, although in FIGS. 8 to 10 only schematically one layer for the material web 4 is represented, whereas in FIGS. 11 to 16 no material web is represented, the technique described by means of these figures can also be applied in combination with everything described in the introduction as well as by means of FIGS. 1 to 2.

(46) Substantially, FIGS. 5 to 16 aim at describing a roller which applies the technique of the invention and thus also can be applied in a production process according to FIG. 1.

(47) As known, by LVT tiles square tiles as well as rectangular plank-shaped tiles may be understood.

(48) The printed motif can imitate a well-defined material, such as wood or stone, but may also be a fancy motif.

(49) In the case that the motif represents wooden planks, these may be situated with their longitudinal direction parallel to the longitudinal direction of the material web as well as transverse thereto. The embossment motifs on the roller then are directed circumferentially or axially, respectively.

(50) It is noted that the technique of the invention for bringing the embossments into register with the printed motif and maintaining it like this, possibly can also be combined with other techniques aiming at the same effect. Such other techniques are, for example, the controlled stretching of the decor layer prior to the lamination thereof and/or the controlled stretching of the entire material web prior to feeding it to the roller.

(51) Herein above, the “intermediate spaces” and “intermediate distances” form identical terms. When these are “varied” or “altered”, it is meant that the distance thereof is altered in circumferential direction. Thus, an “intermediate space” does not necessarily have to be considered a completely open space, but substantially only aims at an interval which is present between two embossing patterns, or between the beginning and end of the same embossing pattern.

(52) The present invention is in no way restricted to the embodiments described by way of example and represented in the figures; on the contrary, such methods and device can be realized according to various variants, without leaving the scope of the invention.