PLATE, PANEL OR SIMILAR, OF THERMOFORMABLE MULTILAYER MATERIAL AND METHOD FOR ITS FABRICATION

Abstract: A plate, panel, or similar, of thermoformable multilayer material, comprises at least one supporting layer (1), made of foamed plastic, and at least one coating layer (2, 6) on at least one of the faces of the supporting layer (1). According to the invention, the coating layer itself and/or an intermediate layer between the said coating layer and the supporting layer made of foamed plastic (1) is made of at least one layer of natural fibers or synthetic fibers or mixtures of said fibers in the form of one or more sheets (2) with small wrinkles, corrugations or similar, that is of creped sheet, namely of crepe paper. The invention also provides a method for fabrication of the said plate.

Description: PLATE, PANEL, OR SIMILAR, OF THERMOFORMABLE MULTILAYER MATERIAL AND METHOD FOR ITS FABRICATION The invention relates to a plate, panel, or similar, of a multilayer material made of thermoformable material, comprising at least one supporting layer made of foamed plastic, and at least one coating layer on at least one of the faces of the supporting layer. It is an object of the invention to provide a plate, a panel, or similar, of a multilayer, thermoformable material of the type described hereinbefore, in such a way that it can have a good stiffness and solidity, with no excessive increase of the specific weight, without compromising the thermoformability of the panel, and with no considerable cost increase for the material and the abrication. Particularly, the invention aims at providing plates, panels, or similar of a thermoformable material, with supporting layers made of foamed plastic, with such properties of stiffness, weight and cost as to allow for use in the fabrication of lining panels, and especially vehicle lining panels, or similar, such as the so-called hatracks, the lining of the body sides, of the doors, and particularly the headlining, etc. The invention achieves the above stated purposes by providing a multilayer panel of thermoformable material of the type described hereinbefore, in which the coating layer itself, or an intermediate layer between the said coating layer and the foamed plastic supporting layer, is made of at least one layer of natural fibers or synthetic fibes or mixtures of said fibers, in the form of a sheet with small wrinkles, corrugations or similar, that is of creped sheet. Particularly, the invention provides a sheet of natural, cellulosic material, namely crepe paper, which is fixed, glued or similar, on the supporting layer. Alternatively, the sheet provided with wrinkles, or creped sheet, may be made of plastic fibers. The fixing of the wrinkled or creped sheet, that is the crepe paper layer, can be made in any way. As preferred examples, the invention provides glueing of the said sheet on the supporting layer, for example by glues, resins, or thermoplastic materials, properly heated, or by sandwiching between the said sheet and the supporting layer, a tacky or a thermoplastic film, or similar. Thus, the wrinkled or creped sheet may form either the actual outer coating layer of the supporting layer or an intermediate layer, between a different outer coating layer and the supporting layer. The said outer coating layer, too, may be fixed to the crepe paper layer in the same way as described above about the latter, or even otherwise. The type of glues, resins, thermoplastic materials, or tacky films, depends on the typology of the foamed plastic used for the supporting layer and on the typology of materials and structure of the eventual coating layer. As outer coating layers, there may be used textiles, felts, not woven textiles, mat, or similar, of natural fibers, synthetic fibers or combinations of the said fibers, or even plastic films, sheets, or similar, sheets of natural or synthetic leather, or other types of coatings. Preferably, the supporting layer is coated on both faces by at least one wrinkled or creped sheet, particularly by a crepe paper sheet. In a preferred embodiment, the crepe paper layer or layers are fixed to the supporting layer by means of resins or thermoplastic materials, which have been previously spread, while in the heated condition at the melted or anyway pasty/plastic state, on the face of the wrinkled or creped sheet or sheets, that is of crepe paper, which is meant to adhere against the supporting layer. The wrinkled or creped sheet so prepared is fixed to the supporting layer made of foamed material through heating of the side on which the layer of resin or thermoplastic material is spread, and through its compression on the supporting layer. Thanks to the expedients disclosed above, the material according to the invention allows to achieve in a simple and cheap manner the forming and stiffness properties, suitable for the use of the latter in the fabrication of lining panels, or similar. During thermoforming, the crepe paper, that is the wrinkled or 97/27998 PC17EP97/O0396 creped sheet complies to the deformations transmitted to the panel, without tearing. Furthermore, the use of crepe paper allows to limit the specific weight of the material and to increase the percentage of recyclable and/or degradable material, reducing its environmental impact. The invention also provides other characteristics which form the subject of the dependent claims. The characteristics of the invention and the advantages derived therefrom will appear more clearly from the following description of some non-limiting embodiments, illustrated in the annexed drawings, in which: Fig. 1 shows a cross section through a first embodiment of the plate, panel, or similar, according to the invention. Fig. 2 shows, like fig. 1 , a variant embodiment of the invention. Fig. 3 schematically shows an example of fabrication of a plate or panel according to the invention. Referring to fig. 1, a multilayer thermoformable material according to the invention is made of a supporting layer of foamed plastic, preferably polypropylene or foamed polyethylene, referred to with 1. The said supporting layer 1 may be of several thicknesses, according to the final use of the part made therewith, and the thickness may vary from 1 to some mm, preferably from 1 to about 10 mm, especially from 3 to 5 mm. The density of the supporting layer 1 may also vary according to the final use and preferably in a range from 5 to 150 Kp/m 3 . The supporting layer 1 is coated on one or both faces by at least one additional layer 2, made of a sheet provided with wrinkles, small corrugations distributed in a substantially homogeneous way over its extension, or creped. Particularly and preferably the said sheet 2 is made of crepe paper or of woven or not woven textiles, mat, felts, other synthetic and/or natural materials, even in combination to each other, as well as thermoplastic materials, for example polypropylene fibers. The application of these materials on one or both faces of the supporting layer 1 allows for a good stiffness of the part, keeping the specific weight reduced with respect to prior art materials. Particularly, the creped sheet 2 has good properties of stretching on molding of the material, thus preventing from tearing in case of very marked deformations. Crepe paper, in particular, is a natural and biodegradable component of the material, and reduces the environmental impact of the latter. The sheet 2 made of crepe paper or thermoplastic fibers or similar, is applied on the supporting layer 1 of foamed material in several ways. According to a first embodiment, it is possible to make use of adhesives, particularly thermosetting adhesives. In an alternative embodiment, ther are provided thermoadhesive films and/or thermoplastic films, referred to with 3 in figs. 1 and 2. Alternatively to what described above, it is possible to use resins or thermoplastic materials, which are spread at the melted state on the side for adhesion with the sheet 2 made of crepe paper or of other coating material, and which are referred to with 3' in fig. 3. The said adhesives, the said resins and the thermoplastic material spread on the layer 2 are obviously to be compatible with the material which forms the supporting layer 1. Particularly, with a supporting layer made of foamed polypropylene, advantages are drawn from the use of polypropylene as adhesive thermoplastic material 3' , spread over the coupling side of the sheet 2 of crepe paper, or as thermoplastic film 3 for mutual adhesion of the two layers 2 and 1. A possible method for coupling the crepe paper sheet or sheets to the supporting layer 1 is schematically shown in fig. 3. The face of the crepe paper sheet or sheets 2 which is in front of the supporting layer 1 and on which a layer 3' of resin or thermoplastic material has been previously spread, are heated by heating means 4 so as to reach a state of softening or substantial melting. Further, the said crepe paper sheet or sheets 2 are pressed against the supporting layer made of foamed material 1, fixing to it thanks to the layer 3' made of heated thermoplastic material. The crepe paper sheet or sheets 2, with one side spread of thermoplastic material 3' , are reelable in reels 5, and the method for coupling to the supporting layer 1 may be executed in a continuous operation. Referring to figs. 1 and 2, the crepe paper sheet 2 may directly be the outer coating layer of the supporting layer 1 or may be an intermediate layer between the supporting layer 1 and an outer coating layer 6. This outer coating layer 6, though shown in the form of textile in figs. 1 and 2, may be of any type, and be made of natural or synthetic material, particularly it may be a woven textile, a not woven textile, a mat, a felt, or similar made of natural fibers, of synthetic fibers or of a mixture of said fibers. Alternatively, the coating layer 6 may be made of a layer of natural leather or synthetic leather. On one or both sides of the supporting layer 1 made of foamed material, there may be applied, in the form of outer coating or intermediate layer, even more overlapping layers, each made of a wrinkled or creped sheet, particularly at least one of these layers being made of a crepe paper sheet. The considerable stretching which may be imposed particularly to crepe paper, allows for its application both in a processing phase taking place previously and separately with respect to the molding phase of the multilayer material, like, for example, according to the method of fig. 3, and during the molding phase itself, of the material eventually together with the possible additional outer coating sheet or sheets 6. There may be also assumed a previous coupling between the crepe paper sheet or sheets and the outer 97/27998 PC17EP97/00396 8 overlapping coating layer 6, before fixing both said layers 2, 6 with the supporting layer, both according to a method analogous to that of fig. 3 and during the thermoforming itself of the material. Moreover, there may be also provided that the crepe paper sheet or sheets 2 and the coating layer or layers be fixed to each other and, at the same time, to the supporting layer 1, through a method according to fig. 3 or while thermoforming them. Naturally the invention is not limited to the embodiments described and illustrated herein, but may be greatly varied, especially as regards construction. So, for example, noteworthy results may be also reached by using smooth paper sheets or plastic films, that is withouts wrinkles or crepes. Furthermore, the fixing of the paper or plastic sheet, either creped, or smooth, may also be carried out through melting of the surface layer of the foamed plastic supporting layer. All this without departure from the guiding principle disclosed above and claimed below.

Claims: CLAIMS 1. Plate, panel, or similar of thermoformable multilayer material, comprising at least one supporting layer (1) , made of foamed plastic, and at least one coating layer (2, 6) on at least one of the faces of the supporting layer (1) , characterized in that the coating layer itself and/or an intermediate layer between the said coating layer and the supporting layer made of foamed plastic (1) is made of at least one layer of natural fibers or synthetic fibers or mixtures of said fibers in the form of one or more sheets (2) with small wrinkles, corrugations or similar, that is of creped sheet. 2. Plate as claimed in claim 1, characterized in that the sheet or sheets (2) are made of natural, cellulosic material, namely crepe paper, and are fixed, glued or similar, on the supporting layer (1) . 3. Plate as claimed in claims 1 or 2, characterized in that the wrinkled or creped sheet or sheets (2) may form either the actual outer coating layer of the supporting layer (1) or an intermediate layer between a different outer coating layer (6) and the supporting layer (1) . 4. Plate as claimed in one or more of the preceding claims, characterized in that the creped or wrinkled sheet or sheets (2) and/or the outer coating layer or layers (6) are glued to the supporting layer (1) , for example by means of glues, thermosetting glues, resins, or thermoplastic materials, which are properly heated, or by sandwiching between the said sheets (2) and/or the said coating layers (6) and the underlying layer (1) or sheet (2) , a tacky or thermoplastic film, or similar (3) . 5. Plate as claimed in one or more of claims 1 to 3, characterized in that the wrinkled or creped sheet or sheets (2) , that is crepe paper, and/or the outer coating layer and/or layers (6) have at least on one of their faces, a layer of resin or thermoplastic material (3' ) , which is spread at the plastic or substantially melted state on the sheets (2, 6) and is heated up before coupling of the sheets (2, 6) to the underlying layer (1) or sheet (2) . 6. Plate as claimed in one or more of the preceding claims, characterized in that, as outer coating layers (6), there may be used textiles, felts, not woven textiles, mat, or similar, of natural fibers, synthetic fibers or combinations of the said fibers, or even plastic films, sheets, or similar, sheets of natural or synthetic leather, or other types of coatings. 7. Plate as claimed in one or more of the preceding claims, characterized in that the supporting layer (1) is coated on both faces by at least one wrinkled or creped sheet (2) , particularly by a crepe paper sheet. 8. Plate as claimed in one or more of the preceding claims, characterized in that it comprises a supporting layer (1) made of foamed polypropylene. 9. Plate as claimed in claim 8, characterized in that as adhesives for fixing the wrinkled or creped sheet or sheets (2) , particularly the crepe paper sheets (2) and/or the outer coating layers (6) , the material used is polypropylene, either in the form of thermoplastic film (3) or in the form of layer (3' ) spread on the coupling face of the sheets (2) or of the coating layers (6) . 10. Plate as claimed in one or more of the preceding claims, characterized in that the supporting layer (1) has a thickness from 1 to about 10 mm, particularly from 3 to 5 mm. 11. Plate as claimed in one or more of the preceding claims, characterized in that the supporting layer (1) has a density form 5 to 150 Kp/m 3 . 12. Method for fabrication of a plate as claimed in one or more of the preceding claims, characterized in that only the wrinkled or creped sheet or sheets (2) and/or also the coating layers (6) are fixed to each other and to the supporting layer (1) during the thermoforming of the plate itself. 13. Method for fabrication of a plate as claimed in one or more of the preceding claims 1 to 11, characterized in that there is provided a previous phase for coupling at least one sheet (2) and/or at least one coating layer (6) to the supporting layer (1) before the thermoforming of the plate itself. 14. Method as claimed in claim 13, characterized in that there is provided a phase for hot spreading on one side of each wrinkled or creped sheet (2) and/or of each coating layer (6) of a tacky material (3'), particularly a resin or a thermoplastic material, preferably the same thermoplastic material of which the supporting layer (1) is made, for example polypropylene, or a compatible thermoplastic material, and a following phase of simultaneous or sequential coupling, of the sheet or sheets (2) and/or of the coating layers (6) provided with the layer of resin or of thermoplastic material spread (3' ) on the supporting layer (1) , each layer spread (3' ) with resin or thermoplastic material being subject to heating up to a temperature at which the said layer (3' ) takes a pasty or substantially melted state, and the sheet or sheets and/or the layers (2, 6) being compressed against the supporting layer (1) or against their respective directly underlying layer (2) . 15. Method as claimed in calim 14, characterized in that the phase for coupling the wrinkled or creped sheet or sheets (2) and/or the coating layers (6) is executed in a continuous operation, the said sheets (2) and/or the said coating layers (6) being provided with the layer spread (3') with resin or thermoplastic material rolled in reels (5) . 16. Method as claimed in one or more of the preceding claims, characterized in that the fixing of the sheets (2) to the supporting layer (1) may also be carried out through melting of the surface layer of the foamed plastic supporting layer (1) itself. 17. Plate as claimed in one or more of the preceding claims, characterized in that the paper or plastic sheets (2) may eventually be smooth or made of smooth plastic films. 18. Plate, panel, or similar of thermoformable multilayer material and method for its fabrication, substantially as described, illustrated and for the purposes stated above.

Inventors: ODINO ADRIANO, VENERE GIORGIO, ODINO, ADRIANO, VENERE, GIORGIO
Applicants: GOR APPLIC SPECIALI SRL, G.O.R. APPLICAZIONI SPECIALI S.P.A.
Application year: 1997
Main classification: B32B27
IPC codes: B32B3, B32B5