GB2085357A

GB2085357A - Laminated block and method of manufacturing parquet boards or squares by means of such blocks

Info

Publication number: GB2085357A
Application number: GB8125901A
Authority: GB
Original assignee: Tarkett AB
Current assignee: Tarkett AB
Priority date: 1980-08-27
Filing date: 1981-08-25
Publication date: 1982-04-28
Also published as: FR2495056B1; GB2085357B; NO812823L; ATA360381A; FR2495056A1; DK377881A; NL8103889A; FI812654A7; NO152680C; DE3132964A1; NO152680B; FI812654L; AT379845B

Abstract

A flooring block with a body (10) and a thin wearing layer (14) secured thereto. The body has, on its opposite sides, layers (28, 29) of a Brinell surface hardness in excess of about 5 kg/mm<2>. The body layers may consist of, for example, metal foil or melamine paper which is glued to one or more layers of fibre or chip board. The wearing layer is suitably of a thickness of form 0.4 to 0.7 mm. The thus constructed body (10, 11) provided with hard layers effectively prevents deformation of the thin wearing layer (14) on point loading, and thus is highly dimensionally stable. Parquet boards or squares are produced by the edge surfaces of such blocks being provided with tongues or grooves. <IMAGE>

Description

SPECIFICATION Laminated block and method of manufacturing parquet boards or squares by means of such blocks The present invention relates to a block having a body, a wearing layer of wood secured to one face of the body and having a thickness of less than 1 mm, and a crossbanding layer secured to the opposite face of the body of approximately the same thickness as the wearing layer.

Solid wood, in particular pine and oak wood, was long the dominant flooring material because of its good insuiating properties, wearing strength, aesthetically attractive appearance and low price.

However, prices eventually rose and at the same time attempts were made to fine substitutes. One such substitute was the so-called parquet board or square with a body and a wearing layer of but a few millimetres' thickness secured thereto. Thanks to this product, it was possible to cut prices, and wooden floors once again became an interesting alternative. This product, however, suffers from the drawback that it is relatively sensitive to point loading and can be ground only once, or twice at most, because of the insignificant thickness of the wearing layer. Moreover, this parquet board or square has become relatively expensive, for which reason the possibilities of reducing the prices and, at the same time, improving, if possible, the strength properties of the wearing layer are again being studied.

It has been ascertained that the thickness of the wearing layer can be reduced if it is simultaneously hardened, but if a board or block provided with such a wearing layer is to satisfy the normal demands for strength and resistance to abrasion, a satisfactory body must be produced.

The object of the present invention is precisely to provide a body that supports the wearing layer in the correct manner and, moreover, is dimensionally stable.

This object is realized in that the body comprises at least two layers of material which are interconnected by means of an interjacent layer, said material layers having a Brinell surface hardness in excess of about 5 kg/mm2.

Laminated parquet boards or squares are tradi tionaliy manufactured in that wearing layer pieces are placed in adjoining relationship according to a desired pattern on a glue-coated interjacent layer which, on its rear face, has a crossbanding layer which is applied before, or in conjunction with, the application of the wearing layer. One drawback inherent in traditional laminated parquet boards or squares is, apart from the above, that they allow for relatively few long-piece patterns, for example solely longitudinal, parallel pieces or alternatingly longitudinal and transverse pieces. Consequently, many old parquet patterns which were laid in the traditional way have disappeared, for example, the classic herring-bone pattern.

Therefore, the present invention also relates to a method of providing, while employing blocks of the above-mentioned type, parquet boards or squares which, on the one hand, are cheaper than traditional types such that parquet flooring may once again become a realistic alternative to the consumer, and, on the other hand, may be supplied in considerably more pattern types than previously.This method is characterised in that the edge surfaces of the body are provided with tongues or grooves, that at least one tongue and/or groove on each block is gluecoated, that the blocks are oriented in directions dependent upon the desired block pattern of the finished product, with the tongues and grooves of adjoining blocks to be assembled in face-to-face relationship, that the blocks are brought together in the requisite number dependent upon the desired board or square size and subjected, while being held down, to pressure in directions at right angles to one another for purposes of uniting the tongues or grooves of the blocks, and that the wearing layers of the blocks are treated.

By applying this method it is thus possible to realize a relatively thin flooring board or square which still possesses better strength properties than previous products of this type. The manufacture of each parquet block separately and the subsequently assembly thereof allow for a greater number of patterns than has hitherto been possible, for example the above-mentioned herring-bone pattern.

The nature of the present invention and its aspects will be more readily understood by the following brief description of the accompanying drawings, and discussion relating thereto.

In the drawings: Figure 1 schematically illustrates in cross-section one of several possible embodiments of a laminated flooring block according to the present invention; Figure 2 schematically illustrates a production line comprising a number of stations; and Figures 3a-3e show examples of square or board patterns which are possible using the method according to the present invention.

The flooring block illustrated in Figure 1 comprises a body 10 which is made from two interconnected layers 10', 10" of fibre board. For attaining the object of the present invention it is sufficient to use one layer, but two layers are shown to illustrate the possibility of laminating the body. The selected fibre board is of a relatively hard type, but there are no particular requirements for hardness in the illustrated embodiment. On the upper face of the thus realized body 10 there is secured a layer 28 which is of a material having a Brinell hardness in excess of about 5 kg/mm2. The layer may consist of thin metal sheeting, a so-called melamine paper or a plastics laminate. A wearing layer 14 of the desired wood type, for example pine or oak, is then glued to said hard layer 28.The wearing layer 14 ids thin and preferably of a thickness of from 0.4 to 0.7 mm and may be hardened in a conventional manner. Similarly, to the surface of the body 10 facing away from the wearing layer 14, there is secured a hard layer 29 corresponding to the layer 28 and, moreover, it is possible to glue a layer of veneer 15 to this layer, if such is desired or necessary.

As will be apparent from the following description, the flooring block manufactured in this manner is preferably arranged fortongue-and-groove jointing.

The different layers are glued together with suitable glue types for each contemplated purpose and by applying technology well-known within the art of parquet board manufacture. When the layers 10' and 10" of fibre board are glued together, the wire faces of the layers are glued to each other. The wearing layer 14 has a lacquer coat, preferably of high-grade polyurethane iacquer, and may, as has been pointed out previously, be hardened in a manner which is well-known in the art.

The hard layers 28 and 29 may also be produced by the use of but one fibre board which, in such an event, is surface-hardened or provided with a coating by brushing such that the desired hardness is obtained. As in the above described embodiment, the wearing surface 14 is thereafter glued to one face while a crossbanding layer 15 is applied to the other face of the board 10.

A laminated block manufactured in this manner is highly wear-resistant and insensitive to point loading. While it is impossible to distinguish it by appearance from prior-art products, it can be produced at a very competitive price. The block is intended in particular for flooring but is, naturally, usable for many other purposes, especially the manufacture of furniture, kitchen fittings etc.

Figure 2 shows, highly schematically, the method of manufacture of parquet squares or boards according to the invention. First, a body or intermediate layer 10 consisting of one or more fibre or chip boards hardened by the gluing thereto of hard layers, hardening or coating, is introduced into a station 11 where it is coated with glue on opposing flat faces. The application of glue is effected by means of conventional glue application rollers 12. In the next station 13, the body 10 is united with a wearing layer 14 and a crossbanding layer 15. The wearing layer 14 consists of veneer which is of a thickness of less than 1.0 mm and may be hardened in a manner well-known in this art. The crossbanding layer 15 also consists of veneer, possibly of poorer quality than the wearing layer 14.In the pressing station 16, the block 19 consisting of the body 10, the wearing layer 14 and the crossbanding layer 15 is pressed between press jaws 30, 30 for rapid curing of the glue. Thereafter, the longitudinal edge surfaces of the block 19 are treated, for example planed, in the station 17, it being also possible at this stage to form tongues or grooves in the body 10. Said treatment may also include bevelling ofthe longitudinal edges of the wearing layer. The transverse edge surfaces are treated in a corresponding manner in the station 18. In the station 20, the requisite number of tongues and grooves is coated with glue prior to the subsequent assembling operation which takes place in the station 21.

A number of blocks 19 called for by the desired square or board size is supplied to the assembly station 21,the blocks being placed in approximately those positions they are to assume in the finished product, for example longitudinally, transversely or diagonally of the longitudinal direction of the finished product. In the drawing, the blocks 19 are shown placed for the manufacture of a board with mutually offset longitudinal blocks 19. The blocks 19 thus in place are then exposed to pressure in opposite directions, as shown by the arrows 22-24, at the same time as they are held down by means of a hold-down device (not shown), the tongues of the blocks 19 being caused to penetrate into grooves provided therefor such that a board or square is obtained. Curing of the glue may take place in this station or in a following station (not shown).After curing of the glue, the thus obtained square or board can be surface-treated, for example brushed with a brush 26 or blasted in a station 25 and finally lacquered in a station 27.

Transport of bodies 10, layers 14,15 and blocks 19, as well as finished squares or boards takes place with the use of conventional means, for example, one or more endless conveyors.

Figures 3a-3e show examples of parquet patterns which may easily be produced by means of the method according to the present invention.

The produced square or board possesses very good strength properties because the wearing layer, as a result of its slight thickness, is as hard as the supporting surface of the body. Moreover, as a result of the method, unconventional in this art, of first manufacturing blocks separately and then bringing them together for assembly, it is possible, as has been pointed out above, to produce many different parquet patterns.

Claims

1. A laminated block comprising a body, a wearing layer of wood secured to one side of the body and having a thickness of less than 1 mm, and a crossbanding layer secured to the opposite face of the body of approximately the same thickness as the wearing layer, wherein the body comprises at least two layers of material which are interconnected by means of an interjacent layer and which have a Brinell surface hardness in excess of about 5 kg/ mm2.

2. A block as claimed in claim 1, wherein the material layers consist of plastic laminate, metal foil or a material of corresponding hardness, or of layers produced by hardening or coating the surfaces of the interjacent layer which consists of a fibre or chip board.

3. A block as claimed in claim 1 or claim 2, wherein the interjacent layer is formed of two fibre boards which are glued together with the wire sides facing each other.

4. A block as claimed in any one of the preceding claims, wherein the wearing layer has a thickness of from 0.4 to 0.7 mm.

5. The block claimed in any one of the preceding claims, wherein the wearing layer is hardened in a conventional manner.

6. A block substantially as hereinbefore described with reference to and as illustrated by Figures 1 to 3 ofthe accompanying drawings.

7. A method of manufacturing a parquet board or square using rectangular blocks with a wearing layer of wood and of a thickness of less than about 1.0 mm, a body of fibre or chip board which, on its opposite sides, has material layers of a Brinell hardness in excess of 5 kg/mm2, and a crossbanding layer of substantially the same thickness as the wearing layer, wherein the edge surfaces of the body being provided with tongues or grooves, and at least one tongue and/or groove of each block being coated with glue, and the blocks being orientated in directions dependent upon the desired pattern of the finished product, with the tongues and grooves of adjoining blocks to be assembled in a face-to-face relationship, the blocks are brought together in requisite numbers dependent upon the desired board or square size and subjected, while being held down, to pressure in directions at right angles to one another for purposes of uniting the tongues and grooves of the blocks, the wearing layers of the blocks being then suitably treated.

8. The method claimed in claim 7, wherein the wearing layers of the block are treated by brushing or blasting.

9. The method claimed in claim 7 or 8, wherein the wearing layers of the blocks are treated by bevelling of the longitudinal edges thereof.

10. A method substantially as hereinbefore de scribed with reference to and as illustrated by Figure 2 of the accompanying drawings.