THERMOCOMPRESSION DEVICE FOR PRODUCING RECYCLABLE HONEYCOMB PLATES AND METHOD IMPLEMENTED USING SAME

Abstract

The invention relates to a thermocompression device for producing recyclable honeycomb plates with high mechanical strength, which, by means of the proposed configuration, enables high-speed production with an optimised operating width. For this purpose, the device comprises an area for continuously heating and pressing the supplied sheet, a cooling area, a calendering area and a moulding area. Advantageously, the moulding area comprises forming rollers provided with protuberances arranged in continuous rows distributed on the surface of the forming rollers, such that the rows are arranged cross-wise with respect to the sheet supply direction. Recyclable honeycomb plates are thus obtained. The invention also relates to a method implemented using the described thermocompression device.

Claims

1. A thermocompression device for producing recyclable honeycomb plates of the types supplied with sheets of recyclable material including a fabric and a thermoplastic material, the thermocompression device comprising: a plurality of drive rollers, a plurality of heated thermocompression rollers and a plurality of forming rollers having protuberances with a half-hexagon geometric shape; the thermocompression rollers and the forming rollers being arranged in pairs, and whereas the thermocompression device is defined by: an area for continuously heating and pressing the sheet having at least a first infrared radiation heating element and thermocompression rollers, wherein the temperature of the area for continuously heating and pressing is equal to or higher than the melting temperature of the thermoplastic material of the sheet, a cooling area for cooling the sheet having a water-chilled cooling element, a calendering area for calendering the sheet having at least a second infrared radiation heating element at a temperature equal to or higher than the melting temperature of the thermoplastic material of the sheet, a moulding area where the forming rollers are arranged at a temperature lower than the temperature of the calendering area, wherein the protuberances of the forming rollers are arranged in continuous rows distributed on the surface of the forming rollers, such that the rows are arranged cross-wise with respect to the direction for supplying the sheet.

2. The thermocompression device for producing recyclable honeycomb plates of the types supplied with sheets of recyclable material according to claim 1, further comprising in that a pressure of at least 7 MPa is applied in the area for continuously heating and pressing and in the moulding area.

3. The improved thermocompression device for producing recyclable honeycomb plates of the types supplied with sheets of recyclable material according to claim 1, further comprising in that the speed of supplying the sheet of recyclable material is at least 4 m/min.

4. The improved thermocompression device for producing recyclable honeycomb plates of the types supplied with sheets of recyclable material according to claim 1, further comprising in that the fabric of the sheet is a non-woven fabric, a low-grammage fabric with a grammage between 40 and 150 g/m.sup.2 or a fabric with filament yarns.

5. The improved thermocompression device for producing recyclable honeycomb plates of the types supplied with sheets of recyclable material according to claim 1, further comprising in that the thermoplastic material of the sheet is made up of thermoplastic fibres or a thermoplastic film with a grammage between 20 and 75 g/m.sup.2.

6. The improved thermocompression device for producing recyclable honeycomb plates of the types supplied with sheets of recyclable material according to claim 1, further comprising in that the honeycomb plate obtained in the moulding area has a width between 100 and 200 cm.

7. A method for producing recyclable honeycomb plates according to the thermocompression device of claims 1 comprising: supplying a sheet including a fabric and a thermoplastic material to the area for continuously heating and pressing by means of the drive rollers, heating and pressing the sheet at a temperature equal to or higher than the melting temperature of the thermoplastic material, by the first heating element and the thermocompression rollers, supplying the sheet to the cooling area by the drive rollers, cooling the sheet by means of the water-chilled cooling element, supplying the sheet to the calendering area by the drive rollers, calendering the sheet by the application of heat and pressure with the second heating element at a temperature equal to or higher than the melting temperature of the thermoplastic material of the sheet, supplying the sheet to the moulding area by the forming rollers, cooling and moulding the sheet by the half-hexagon shaped protuberances of the forming rollers for producing the recyclable honeycomb plate.

8. The method for producing recyclable honeycomb plates according to claim 7, further comprising in that the honeycomb plate obtained in the step of cooling and moulding the sheet has a width between 100 and 200 cm.

9. The method for producing recyclable honeycomb plates according to claim 7, further comprising in that the honeycomb plate obtained in the step of cooling and moulding the sheet is subjected to a step of gluing to another honeycomb plate by the deposition of an adhesive.

10. The method for producing recyclable honeycomb plates according to claim 7, further comprising in that the honeycomb plate obtained in the step of cooling and moulding the sheet is subjected to a step of gluing to another honeycomb plate by a hot plate.

11. The method for producing recyclable honeycomb plates according to claim 7, further comprising in that a pressure of at least 7 MPa is applied in the step of heating and pressing in the area for continuously heating and pressing and in the step of cooling and moulding in the moulding area.

12. The method for producing recyclable honeycomb plates according to claim 7, further comprising in that the speed of supplying the sheet to the thermocompression device is at least 4 m/min.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] To complete the description that will be made below and for the purpose of helping to better understand the features of the invention, a set of drawings is attached as an integral part of said description in which the following is depicted in an illustrative and non-limiting manner:

[0048] FIG. 1 shows a depiction of the thermocompression rollers making up a known thermocompression device.

[0049] FIG. 2 shows a detailed front view of an example of thermocompression rollers which are part of a known thermocompression device.

[0050] FIG. 3 shows the sheet obtained from two thermocompression rollers which are part of a known thermocompression device.

[0051] FIG. 4 shows a thermocompression device according to a preferred embodiment of the present invention.

[0052] FIG. 5 shows a detail of a perspective view of forming rollers arranged in the moulding area of the thermocompression device depicted in the preceding figure.

[0053] FIG. 6 shows a front view of the forming roller depicted in the preceding figure.

PREFERRED EMBODIMENT OF THE INVENTION

[0054] FIGS. 3, 4, 5 and 6 show a preferred embodiment of the thermocompression device for producing recyclable honeycomb plates of the types supplied with sheets (4) of recyclable material including a fabric and a thermoplastic material.

[0055] In that sense, the proposed thermocompression device comprises a plurality of drive rollers (3), a plurality of heated thermocompression rollers (1) and a plurality of forming rollers (2) having protuberances (5) with a half-hexagon geometric shape; the thermocompression rollers (1) and the forming rollers (2) being arranged in pairs, as depicted in FIG. 4.

[0056] It should be indicated that the following areas are defined in the thermocompression device: [0057] An area for continuously heating and pressing (8) the sheet (4) having a heating element made up of at least a first infrared radiation heating element (6) and thermocompression rollers (1), wherein the temperature of the area for continuously heating and pressing (8) is equal to or higher than the melting temperature of the thermoplastic material of the sheet (4).

[0058] Preferably, a pressure of at least 7 MPa is applied in the area for continuously heating and pressing (8). Advantageously, by melting the thermoplastic material with a pressure of at least 7 MPa, the sheet (4) is prevented from shrinking. [0059] A cooling area (9) for cooling the sheet (4) having a water-chilled cooling element (7). Therefore, a sheet of smaller thickness with respect to the thickness of the sheet (4) fed to the area for heating (8) is achieved, and a homogenous distribution of the thermoplastic material across the entire extension of the sheet (4) of non-woven fabric is achieved. This homogenous distribution translates into a final plate with optimum mechanical strength. [0060] A calendering area (10) for calendering the sheet (4) having a heating element made up of at least a second infrared radiation heating element (6) at a temperature equal to or higher than the melting temperature of the thermoplastic material of the sheet (4). The purpose of this step is to slightly melt the thermoplastic material of the sheet (4) again prior to the moulding thereof in order to produce the honeycomb plate. [0061] A moulding area (11) where the forming rollers (2) are arranged at a temperature lower than the temperature of the calendering area (10). Preferably, a pressure of at least 7 MPa is applied in the moulding area (11), such that the forming rollers (2) with the half-hexagon shape cool the sheet (4), with the latter becoming a solid format and acquiring the honeycomb structure permanently. The protuberances (5) of each pair of forming rollers (2) are located offset with respect to one another in order to facilitate the thermocompression of the sheet (4).

[0062] Therefore, to produce a recyclable honeycomb plate using the improved thermocompression device of the present invention, the following method is followed: [0063] Supplying a sheet (4) including a fabric and a thermoplastic material to the area for continuously heating and pressing (8) by means of the drive rollers (3). [0064] Heating and pressing the sheet (4) at a temperature equal to or higher than the melting temperature of the thermoplastic material, by means of the first heating element (6) and the thermocompression rollers (1). Preferably, a pressure of at least 7 MPa is applied in the step of heating and pressing in the area for continuously heating and pressing (8). [0065] Supplying the sheet (4) to the cooling area (9) by means of the drive rollers (3). [0066] Cooling the sheet (4) by means of the cooling element (7). [0067] Supplying the sheet (4) to the calendering area (10) by means of the drive rollers (3). [0068] Calendering the sheet (4) by means of the application of heat and pressure with the second heating element (6) at a temperature equal to or higher than the melting temperature of the thermoplastic material of the sheet (4). [0069] Supplying the sheet (4) to the moulding area (11) by means of the forming rollers (2). [0070] Cooling and moulding the sheet (4) by means of the half-hexagon shaped protuberances (5) of the forming rollers (2) for producing the recyclable honeycomb plate. Preferably, a pressure of at least 7 MPa is applied in the step of cooling and moulding in the moulding area (11).

[0071] Once the honeycomb plates are produced, a step of gluing the plates is performed to generate the panel with a honeycomb structure. For this purpose, a process of gluing two plates by means of the deposition of an adhesive, a technology commonly known as hot-melt lip, is contemplated, obtaining cubic blocks of up to 1 m.sup.3 in size by gradually combining pairs of plates. These blocks are then cut to the desired measurements.

[0072] Alternatively, the step of gluing two honeycomb plates is performed by means of a hot plate, which allows dispensing with additional adhesives, since the thermoplastic material itself present in the honeycomb plate allows the gluing of the plates upon being heated.

[0073] It should be noted that the incorporation of the area for continuously heating and pressing (8) and the cooling area (9) is of vital importance to increase the production speed with respect to the known devices, as well as to ensure the homogeneity of the honeycomb plate produced. This is due to the particular behaviour of non-woven fabrics when being subjected to specific temperatures that prevent the application of high production speeds in the known devices which lack the mentioned areas (8) and (9). In this way, a completely flat sheet is produced in the two first areas (8) and (9) and the desired area is then formed on said sheet in areas (10) and (11), so the combination of these four areas allows increasing production speed when sheets comprising a non-woven fabric and a thermoplastic material are used.

[0074] One of the novel aspects of the improved thermocompression device of the present invention lies in the arrangement of the protuberances (5) in the forming rollers (2). In this sense, as can be seen in FIGS. 5 and 6, the protuberances (5) of the forming rollers (2) are arranged in continuous rows distributed on the surface of the forming rollers (2), such that the rows are arranged cross-wise with respect to the sheet supply direction (4). This cross-wise arrangement likewise allows increasing production speed, ensuring homogeneity across the entire extension of the sheet (4) and making the best use of the surface thereof, since the entire width thereof is utilized.

[0075] The novel arrangement of the protuberances (5) in the forming rollers (2) of the device of the present invention generates a very advantageous effect which could not be achieved with the rollers known (101) depicted in FIGS. 1, 2 and 3.

[0076] In this sense, it can be seen that in the known devices, the protuberances (100) of the forming rollers (101) are arranged length-wise with respect to the direction for supplying the sheet (102), as can be seen in FIG. 3.

[0077] The known devices are limited to both a maximum speed of 1 m/min (this speed is considered very slow) and a formation width of 15 cm (at the industrial level, this would be about 100-200 cm), where processing becomes extremely difficult at a higher production speed or greater formation width to the point where production is practically impossible.

[0078] However, in the improved thermocompression device of the present invention, the protuberances (5) are arranged cross-wise with respect to the direction for supplying the sheet, which translates into a method that is quicker, more efficient and more homogenous.

[0079] The thermocompression device of the invention proposed in the present application allows working with a speed of supplying the sheet (4) of recyclable material of at least 4 m/min.

[0080] Likewise, it should be indicated that the fabric of the sheet (4) is preferably a non-woven fabric, a low-grammage fabric with a grammage between 40 and 150 g/m.sup.2, or a fabric with filament yarns, whereas the thermoplastic material of the sheet (4) is made up of thermoplastic fibres or a thermoplastic film with a grammage between 20 and 75 g/m.sup.2.

[0081] Finally, it should be indicated that the honeycomb plate obtained in the moulding area (11), i.e., after the step of cooling and moulding the sheet (4), has a width between 100 and 200cm, producing a homogenous recyclable honeycomb plate with optimised mechanical strength.