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Title:
MULTI-LAYER PARQUET BOARD.
Document Type and Number:
WIPO Patent Application WO/2021/060997
Kind Code:
A1
Abstract:
The multilayer parquet board containing at least a surface layer and a wear layer which are joined together by means of a water resistant adhesive, whilst the shape of the sides of the board is adapted to the system of joining adjacent boards, according to the invention, is characterized in that the surface layer (1) has the form of a wooden sheet formed from a cut block (4) arranged from multiple sheets of water-resistant plywood (5) so that in the entire volume of the surface layer (1) wood fibers (5a) and (5b) are arranged alternately, whilst wood fibers (5a) are directed vertically and perpendicularly to the wear layer (2) and wood fibers (5b) are directed horizontally and parallel to the wear layer (2) and moreover plywood boards (5) in the block (4) are joined together by means of an adhesive (3) with an advanced water resistance class, applied linearly at intervals ensuring the layout of the adhesive (3) on the whole surface of the joined plywood sheets (5).

Inventors:
GRZEGORCZYK ZBIEGNIEW (PL)
Application Number:
PCT/PL2020/000079
Publication Date:
April 01, 2021
Filing Date:
September 24, 2020
Export Citation:
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Assignee:
HOLTZEXPORT SPOLKA Z OGRANICZONA ODPOWIEDZIALNOSCIA (PL)
International Classes:
B27L5/00; B27M3/04; B32B3/14; B32B21/00
Foreign References:
DE20105808U12001-08-23
EP1231038A22002-08-14
FR697624A1931-01-20
Attorney, Agent or Firm:
BASA, Graźyna (PL)
Download PDF:
Claims:
Patent claims

1. The multilayer parquet board containing at least the surface layer and the wear layer which are joined together by means of a water- resistant adhesive, whilst the shape of the sides of the board is adapted to the system of joining adjacent boards, is characterized in that the surface layer (1) has the form of a wooden sheet formed from the cut block (4) arranged from multiple sheets of water-resistant plywood (5) so that in the entire volume of the surface layer (1) wood fibers (5a) and (5b) are arranged alternately, whilst wood fibers (5a) are directed vertically and perpendicularly to the wear layer (2) and wood fibers (5b) are directed horizontally and parallel to the wear layer (2) and moreover plywood boards (5) in the block (4) are joined together by means of an adhesive (3) with an advanced water resistance class, applied linearly at intervals ensuring the layout of the adhesive (3) on the whole surface of the joined plywood sheets (5).

2. The parquet board, according to claim 1, is characterized in that the height ”h” of the block (4) out of which the sheet constituting the surface layer (1) was formed equals the width ”b” of the parquet board.

3. The parquet board, according to claim 1, is characterized in that the length ”1” of the block (4) out of which the sheet constituting the surface layer (1) was formed equals the length ”a” of the parquet board.

4. The parquet board, according to claim 1, is characterized in that the block (4) out of which the sheet constituting the surface layer (1) was formed, was cut to a thickness ”g” corresponding to a thickness ”c”of the surface layer (1).

5. The parquet board, according to claim 1 , is characterized in that the floor space of the surface layer (1) is additionally decorated.

6. The parquet board, according to claims 1 and 5, is characterized in that the floor space of the surface layer (1) is decorated by lengthwise brushing or lengthwise brushing and diagonal kerf- cutting.

7. The parquet board, according to claim 1 , is characterized in that the floor space of the surface layer (1) is decorated by sealing and staining or painting or making a decorative print design.

8. The parquet board, according to claim 1 or any of the claims from 6 to 7, is charactrized in that the floor space of the surface layer (1) is impregnated.

Description:
Multilayer parquet board

The subject of the invention is a multilayer parquet board where at least one surface layer is a wooden layer.

Growing competition in the market of producers of floor coverings and the expectations of customers concerning high functional properties of these products, while ensuring attractive purchase prices encourage the companies to seek new possibilities to apply alternative material and structural solutions in this industry. The ecological aspect is also significant. Hardwood harvested from slow- growing trees is becoming less available in the market due to increased deforestation caused by a growing market demand, while regeneration of forests with such a tree stand lasts very long.

Due to being economical with expensive material, such as hardwood harvested from long- growing trees, for example oak, nut-tree, hornbeam or beech, parquet boards are made of at least two layers, i.e. the surface layer and the wear layer. A good quality wear layer should not only have aesthetic qualities, but also has to fulfil certain technical requirements, at least such as: high hardness, resistance to bending and dimensional stability at humidity and temperature fluctuations. Due to the fact that not all wood species possess such properties, wood of a better quality harvested from long- growing trees (oak, beech, exotic wood) is used in present solutions in each case in the wooden wear layers of the multilayer parquet boards. The wear layers from such wood are produced in a solid or veneer form with a different thickness with visible grains arranged in a longitudinal direction of the plank. Softer and simultaneously cheaper wood (birch, poplar, spruce) is used, however, as a wear layer of the multilayer parquet not visible after laying it, whereby, the wear layer can have a solid or glued structure. The wear layer can also be made of plywood, fireboard or composite plate.

In the current state of the art in multilayer parquets with a wooden surface layer there is a tendency to make a wear layer of the parquet from cheaper materials, whereas, the structure of the surface layer always comes down to solid wood or veneer and eventually finishing and decorative elements.

For instance, from the patent application US2017282505 a two-layer parquet is known which contains a surface layer and a wear layer in the form of multiple layers from solid wood, whereby, the layers from solid wood consist of many strips from solid wood arranged next to each other. The adjacent layers from solid wood are arranged tightly next to each other with an overlap on the contact line and are glued together. The surface layer and the wear layer are firmly glued together.

From patent PL/EP2206851 a two-layer parquet board is known where the surface layer is made of solid wood, whereas, the load-bearing board is made of solid wood of a worse quality or of fiberboard, whereby, on the bottom side of the load-bearing board gaps are foreseen which are arranged transversally to the length of the surface layer and are characterized by the fact that each gap has two areas of depth.

From the patent application CN101550759 a solution is known where the parquet board or parquet floor is formed from the wear layer made of plywood and the surface layer made of veneer. In this solution plywood for the wear layer is cut into strips which after being rotated by 90° are arranged next to each other and glued along the sides maintaining a gap between the strips. Thus, some fibers of the load-bearing board are arranged longitudinally and the others perpendicularly to the surface layer of the veneer. It is still the case, however, that the upper layer is made of veneer with grain arranged longitudinally.

In known solutions where the wear layer consists of cut plywood or timber stripes arranged towards the surface layer revealing a mixed structure of plywood, pads are used at the joining points of the respective stripes. By applying pads gaps between stripes are formed and these gaps reduce stress in the wear layer.

Three-layer parquet boards are also known where the wear layer is placed between the surface layer and the lower layer, but in each case even in small quantities hardwood is used in the form of a surface layer with fibers arranged along the parquet.

As can be seen from the above examples, the problem of using cheaper wood material on the surface layer of the multi-layer parquet board by simultaneously maintaining the functional properties of the hard solid wood such as hardness, resistance to scratches, high abrasion resistance has not been solved yet.

Higher and higher standards in the parquet industry make the customers seek a more structured parquet than solid wood which would be deprived of inherent defects of solid wood with anisotropic properties. In order to meet the expectations, the producers must look for high quality wood for the surface layer which is reflected in the price of the parquet.

The aim of the invention is the development of a multilayer parquet board where at least the surface layer is the wooden layer and, at the same time, it will be an ecological and cheap board and will demonstrate technical parameters not worse from the solutions known in the market.

The multilayer parquet board containing at least the surface layer and the wear layer which are joined by means of a water- resistant adhesive, whilst the shape of the sides of the board is adapted to the system of joining adjacent boards, according to the invention, is characterized by the fact that the surface layer has the form of a wooden sheet formed from the cut block arranged from multiple sheets of water-resistant plywood so that in the entire volume of the surface layer, the wood fibers are arranged alternately, whilst some fibers are directed vertically and perpendicularly to the wear layer and the other fibers are directed horizontally and parallel to the wear layer. Preferably, the height of the block from which the sheet constituting the surface layer is formed equals the width of the parquet board. Preferably, the length of the block out of which the sheet constituting the surface layer is formed equals the length of the parquet board. Preferably, the block is cut into sheets of a thickness equal to the thickness of the surface layer. Preferably, the plywood sheets in the block are joined by means of an adhesive with an advanced water resistance class applied linearly at intervals ensuring the layout of the adhesive on the whole surface of the joined plywood sheets. Preferably, the floor space of the surface layer is additionally decorated and impregnated. Preferably, the floor space of the surface layer is decorated by lengthwise brushing or lengthwise brushing and diagonal kerf cutting or by staining or painting or by making a print design on the sealed surface. Preferably, the surface layer is impregnated with oil and varnish.

Unexpectedly, it turned out that the parquet board containing the surface layer from plywood with an arrangement of fibers according to the invention does not only constitute a new decorative solution which has not been known until now but, first of all, demonstrates very good technical parameters in relation to the present parquets such as: mechanical resistance, resistance to temperature and humidity changes resulting from the alternating transversal and longitudinal arrangement of wood fibers in adjacent veneer layers; both in the surface layer, as well as, in the bottom layer of the parquet board, thermal insulation, high impact strength, very high dimensional stability even after soaking and drying, high fire resistance. Moreover, the process uses the material in the form of plywood generally available on the market, whereas plywood can be made of wood harvested from fast growing trees without prejudice to the quality of the parquet and simultaneously the price of such material may be significantly lower. Plywood can also be made of hardwood and it does not have to be first quality wood. Furthermore, plywood can be made of chosen veneer segments deprived of knots and other wood flaws, eventually resulting in obtaining a parquet board whose area is homogeneous and the used wood used does not necessarily have to be expensive.

The multilayer parquet board was presented in the illustration where figure 1 shows an exemplary two-layer board made entirely of plywood in an axonometric projection, figure 2 presents a layer pattern of this board in a cross section, figure 3 presents the pattern of plywood sheets in the block, figure 4 shows a compressed block of sheets from plywood and the cutting direction of the block from which the surface layer is formed, figure 5 presents the board in an axonometric projection with an exemplary decoration made by the method of lengthwise brushing and diagonal kerf-cutting from the top view.

The multilayer parquet board contains at least a surface layer 1 and a wear layer 2 which are joined together by an adhesive 3. The shape of the sides of the board is adapted to the system of joining the adjacent boards, in this example it is the tongue 6 and the groove 7, but in other design options the sides of the desk may be smooth, adapted for gluing or may be equipped with other systems of joining the adjacent boards together. The surface layer 1 has a form of a wooden sheet formed from cutting block 4 whose layers are glued and compacted. The layers in block 4 have a form of water resistant sheets 5 from plywood. After cutting block 4 in a direction perpendicular to the planes onto which the sheets 5 from plywood are glued, the surface layer 1 has wood fibers 5a and 5b arranged alternately throughout the entire volume, whilst the wood fibers 5a are directed vertically in the surface layer 1 and the wood fibers 5b are directed horizontally in the surface layer 1. The arrangement of fibers on surfaces where the sheets from plywood 5 are joined is mutually perpendicular as demonstrated in figure 3, similarly as the arrangement of fibers in plywood which enables to maintain the continuity of the structure of the surface layer 1. Moreover sheets 5 out of which block 4 is formed have a length ”1” corresponding to the length ”a” of the parquet board and are arranged in the block 4 at the height ”h” corresponding to the width „b” of the parquet board. PVAc glue with water resistance -D4 class was used as an adhesive 3 between the surfaces of the joined sheets 5 in the block 4. The glue was distributed linearly on one of the adjacent surfaces where sheets 5 are glued at intervals ensuring an even distribution of the adhesive 3 on the entire surface where sheets 5 are glued after gluing and compressing all sheets 5 in the block 4. Such a gluing method and additionally compressing sheets 5 into the block 4 prevents moisture from penetrating into the surface layer 1. The block 4 after drying is cut into sheets constituting the surface layer 1 of a thickness ”g” which is equal to the thickness ”c”of the surface layer 1. In this design example the surface layer was made of birch plywood, but in other variants sheets 5 used on the surface layer 1 can be made of another type of wood, for example from spruce, hornbeam, oak or poplar. The surface layer 1 of the described texture is glued to the wear layer 2 by means of the adhesive 8, i.e. based on polyvinyl acetate (PVAc) with water resistance - D4 class. The wear layer 2 in this example was made of a single water resistant birch plywood sheet, but in other variants plywood can be made of another wood, for example from spruce, poplar, aspen or another cheap wood. The wear layer 2 can also be made of another wood-based material or material not containing wood. Expansion transversal grooves 9 are made at the bottom of the wear layer 2. In other design options the wear layer 2 can have another structure, known from the state of the art, for example a split structure. The surface 1 of the parquet board may additionally be decorated and impregnated. In the presented design example the surface 1 was sealed and then impregnated with an ultra matt varnish. In other variants the board can be offered for sale as a raw, undecorated and unimpregnated board or can be decorated by lengthwise brushing which gives an effect of a ribbed surface of surface layer 1 or lengthwise brushing and diagonal kerf-cutting as a result of which an impression of a chequered surface of the surface layer 1 is obtained as shown in figure 5. Depending on the type of the prepared surface of the surface layer 1 and the requirements of the customer, the parquet board may be impregnated by oiling or varnishing, whilst prior to varnishing the board may be stained or painted or a designed decorative pattern may be printed on it.