A PROCESS FOR PROVIDING PRODUCTS WITH A HARD AND DECORATIVE SURFACE

Abstract: A process for the manufacturing of products provided with a decorative and hard surface layer (2), the products being for example a wall board, a floor board, a panel, a casing, a dilatation device, a floor beading or the like. At least a) a post-forming quality decorative thermosetting laminate (2'''') or, b) a thermosetting resin impregnated decor sheet (2") or, c) a closest to the surface placed thermosetting resin impregnated so-called overlay sheet (2') of alpha -cellulose and an underlying decor sheet (2"), are placed towards the wall in a mould cavity (1). A predetermined amount of a moulding compound (3) of thermosetting resin, preferrably melamine formaldehyde resin is thereafter placed in the mould cavity (1). The mould is closed and its contents are exposed to heat and pressure so that the moulding compound (3) deliquesces and the resin cures while bonding the surface layer (2), wherein a rigid and non-moisture sensitive product with a decorative surface layer (2) is achieved.

Description: A process for providing products with a hard and decorative surface. The present invention relates to a process for the manufacturing of products provided with a decorative and hard surface layer Products covered with thermosetting laminate are well known They are used foremost where the demands of abrasion resistance is great As example of such products can be mentioned floors, floor headings, table tops and wall panels These products are manufactured by gluing a thermosetting laminate towards a carrier of particle board, fibre board or the like A disadvantage with this method is that details with a complex shape are very difficult and costly to achieve It is for example relatively simple to mill a profile which has the same cross section over its whole length, and then cover the surface thereof with a thermosetting laminate It will become increasingly difficult to manufacture a beading with for example guiding rods on the back side Another disadvantage with this method is that the carriers that normally are used are sensitive to moisture This will lead to that the products achieved will not be suitable for use in wet rooms such as bath rooms or other humid environments According to the present invention the above mentioned problems have been solved so that moisture resistant products with a hard and decorative surface layer can be achieved The invention relates to process for the manufacturing of products provided with a decorative and hard surface layer The products being for example a wall board, a floor board, a panel, a casing, a dilatation device, a floor beading or the like The invention is characterised in that at least, a) a post-forming quality decorative thermosetting laminate or, b) a thermosetting resin impregnated decor sheet or, c) a closest to the surface placed thermosetting resin impregnated so-called overlay sheet of α-cellulose and an underlying thermosetting resin impregnated decor sheet or, d) a closest to surface placed thermosetting resin impregnated so-called overlay sheet of α-cellulose and an underlying non-impregnated decor sheet, are placed towards a wall in a mould cavity A predetermined amount of moulding compound of non-cured or partially cured thermosetting resin, preferably of melamine formaldehyde resin is thereafter placed in the mould cavity The mould is then closed and its contents are exposed to heat and pressure so that the moulding compound deliquesces and the resin cures while bonding the surface layer Hereby a rigid and moisture resistant product with a decorative surface layer is achieved The thermosetting resin utilised for impregnating the decor sheet and the overlay sheet is preferably a melamine formaldehyde resin By this procedure a product with a hard and an abrasion resistant decorative surface can be manufactured in one step, since the thermosetting resins in the different initial materials cure together so that they will form a unit A product can in a corresponding way be provided with additional sheets on other surfaces This can be necessary on products that tends to warp or bend after the compression moulding A second sheet, or a combination of sheets can then be placed on a second surface, opposite to the first surface The two sheets or sheet combinations will then co-operate so that warping and bending are avoided The sheets can be held in place in the mould cavity by means of vacuum. Hereby it will also be possible to place sheets towards the upper surface of the mould cavity The pressure that the contents in the mould cavity will be exposed to is generally within the interval 2 - 500 bar, preferably 50 - 100 bar The temperatures in the mould cavity is normally held between 120 - 200°C, while the interval 130 - 170°C is preferred The process time, as to say the time the mould cavity is closed, pressurised and within the temperature interval is suitably 30 seconds - 10 minutes, preferably 1 - 5 minutes The decor sheet can be monochromatic or patterned with for example wood pattern, marble pattern or a completely fantasy based pattern The inner surfaces of the mould cavity can also be provided with a surface structure, which in the finished product can simulate pores in wood, stone, leather structure or the like This will enhance the realism radically in the finished surface According to one embodiment of the invention a core of particle board, fibre board or the like is placed in the mould cavity so that it is completely surrounded by moulding compound This is normally done by distributing the moulding compound so that one part is placed under the core and a second part is placed on top of the core The moulding compound will, when the mould is closed deliquesce when heated so that it completely surrounds the core The product can by containing a core with a lower density be made lighter This can be specially suitable on products with thick walls Hereby also a considerable saving of the amount of moulding compound can be achieved The good qualities such as a good moisture resistance can be maintained in spite of a relatively large moulding compound saving To further increase the rigidity of the product the moulding compound can suitably contain reinforcing materials such as glass fibres, carbon fibres or the like Also pervious fabrics for example of canvas, glass fibre or the like can be placed in the mould cavity together with the moulding compound. If the product is to be exposed to very high charges prefabricated metal inserts or nets of metal can be placed in the mould cavity together with the moulding compound. The mould cavity is suitably provided with raised surfaces, tracks, groves, ribs, holes or the like which give the shape of the finished product whereby abrasive shaping will become unnecessary By providing the mould cavity with a negative reproduction of a functional detail, this detail can be moulded together with the product in one piece This will give a considerable saving since abrasive shaping will become unnecessary Furthermore some armatures, that normally are applied afterwards utilising screws, glue or the like, be avoided by integrating these functions at the compression moulding process Often at least one of the thermosetting resin impregnated sheets, preferably the outermost one is coated with hard particles for example of silicon dioxide, aluminium oxide and/or silicon carbide with an average particle size of 1 - 80 μm, preferably around 5 - 60 μm These particles are preferably evenly distributed over the surface of the sheet The hard particles will increase the already good abrasion resistance of the surface further They will also give a less slippery surface which can be an advantage in products associated with floors The abrasion resistance is tested according to the European standard EN 438-2/6 1991 According to the standard the wear of the decor layer on the finished product is measured to the so-called IP (initial-point), where initial abrasion starts Suitably at least the surface of the product that is constituted by the decorative hard surface layer has an abrasion resistance measured as IP > 3000 revolutions, preferably > 6000 revolutions The invention will be explained further together with the enclosed figures that show two different embodiments of the invention wherein, -figure 1 shows in cross section a part of an open mould for compression moulding containing a moulding compound, an overlay and a decor sheet, while, -figure 2 shows in cross section a part of a closed mould for compression moulding containing a deliquesced moulding compound, a core of particle board, an overlay, a decor sheet and a post-forming laminate Figure 1 shows in cross section a part of an open mould 1 for compression moulding of products provided with a decorative hard surface 2 A thermosetting resin impregnated overlay sheet of α-cellulose 2' and a thermosetting resin impregnated decor sheet 2" are placed towards the wall in a mould cavity A predetermined amount of thermosetting resin 3 of non-cured or partly cured melamine formaldehyde resin is placed in the mould whereupon the mould is closed and the contents in the cavity 1 is exposed to heat and pressure so that the moulding compound deliquesces and the thermosetting resins cures, whereby a rigid and moisture resistant product provided with a firmly attached decorative and hard surface layer is received Figure 2 shows in cross section a part of a closed mould 1 The deliquesced moulding compound 3 contains a core of particle board 4 A thermosetting resin impregnated overlay sheet 2' of α-cellulose and a non-impregnated decor sheet 2'" are placed towards the lower wall of the mould cavity 1 A decorative thermosetting laminate 2"" of post-forming quality is placed towards the upper wall of the mould cavity 1 The moulding compound 3 is distributed between the upper and the lower side of the core 4 so that this after the compression moulding procedure is completely surrounded by moulding compound The invention is of cause not limited by the embodiments shown since they can varied in different ways within the scope of the invention

Claims: Claims 1 . A process for the manufacturing of products provided with a decorative and hard surface layer (2), the products being for example a wall board, a floor board, a panel, a casing, a dilatation device, a floor beading or the like, characterised in that at least a) a post-forming quality decorative thermosetting laminate (2"") or, b) a thermosetting resin impregnated decor sheet (2") or, c) a closest to the surface placed thermosetting resin impregnated so-called overlay sheet (2') of α-cellulose and an underlying thermosetting resin impregnated decor sheet (2") or, d) a closest to the surface placed thermosetting resin impregnated so-called overlay sheet (2') of α-cellulose and an underlying non-impregnated decor sheet (2'"), are placed towards a wall in a mould cavity ( 1 ), whereafter a predetermined amount of a moulding compound (3) of non-cured or partially cured thermosetting resin, preferably melamine formaldehyde resin is placed in the mould cavity ( 1 ) whereupon the mould is closed and the contents of the mould cavity ( 1 ) are exposed to heat and pressure so that the moulding compound (3 ) deliquesces and the resin cures while bonding the surface layer (2), wherein a rigid and non-moisture sensitive product with a decorative surface layer (2) is achieved 2. A process according to claim 1 characterised in that a core of particle board or fibre board (4) or the like is placed in the mould cavity ( 1 ) so that it is completely surrounded by moulding compound 3 A process according to any of the claims 1 or 2 characterised in that the moulding compound also contains reinforcing materials such as glass fibres, carbon fibres or the like. 4 A process according to any of the claims 1 - 3 characterised in that the mould cavity ( 1 ) is provided with raised surfaces, tracks, groves, ribs, holes or the like which give the shape of the finished product whereby abrasive shaping will become unnecessary 5 A process according to any of the claims 1 - 4 characterised in that at least on of the thermosetting resin impregnated sheets, preferably the outermost one is coated with hard particles of for example silicon dioxide, aluminium oxide and/or silicon carbide with an average particle size of 1 - 80 μm, preferably about 5 - 60 μm A process according to any of the claims 1 - 5 characterised in that at least the surface of the product that is constituted by the decorative hard surface layer (2) has an abrasion resistance measured as IP > 3000 revolutions, preferably > 6000 revolutions

Inventors: KNUTSSON ANDERS, NILSSON JONAS, KNUTSSON, ANDERS, NILSSON, JONAS
Applicants: KNUTSSON ANDERS, NILSSON JONAS, PERSTORP AB, KNUTSSON, ANDERS, NILSSON, JONAS
Application year: 1996
Main classification: B44C5
IPC codes: B29C43, B29C70, B32B21, B32B27, B44C5