U.S. patent application number 16/439037 was filed with the patent office on 2019-09-26 for fibre based panels with a wear resistance surface.
This patent application is currently assigned to Valinge Innovation AB. The applicant listed for this patent is Valinge Innovation AB. Invention is credited to Eddy BOUCKE, Niclas HAKANSSON, Jan JACOBSSON, Kent LINDGREN, Darko PERVAN, Goran ZIEGLER.
Application Number | 20190292796 16/439037 |
Document ID | / |
Family ID | 40753683 |
Filed Date | 2019-09-26 |
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United States Patent
Application |
20190292796 |
Kind Code |
A1 |
PERVAN; Darko ; et
al. |
September 26, 2019 |
FIBRE BASED PANELS WITH A WEAR RESISTANCE SURFACE
Abstract
Building panels with a homogenous decorative surface having a
wear layer comprising fibres, binders and wear resistant particles.
A building panel including a surface layer and a core, the core
including wood fibres, and the surface layer including a
substantially homogenous mix of wood fibres, a binder and wear
resistant particles, the substantially homogenous mix of wood
fibres including natural resins.
Inventors: |
PERVAN; Darko; (Viken,
SE) ; LINDGREN; Kent; (Perstorp, SE) ;
JACOBSSON; Jan; (Landskrona, SE) ; BOUCKE; Eddy;
(Kortrijk, BE) ; ZIEGLER; Goran; (ZIEGLER, SE)
; HAKANSSON; Niclas; (Viken, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Valinge Innovation AB |
Viken |
|
SE |
|
|
Assignee: |
Valinge Innovation AB
Viken
SE
|
Family ID: |
40753683 |
Appl. No.: |
16/439037 |
Filed: |
June 12, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15704634 |
Sep 14, 2017 |
|
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|
16439037 |
|
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12270257 |
Nov 13, 2008 |
9783996 |
|
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15704634 |
|
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60996473 |
Nov 19, 2007 |
|
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61042938 |
Apr 7, 2008 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E04F 2201/0153 20130101;
Y10T 428/24612 20150115; B32B 2309/12 20130101; E04F 15/042
20130101; B32B 21/02 20130101; B32B 2260/046 20130101; B32B 2309/02
20130101; B32B 21/14 20130101; B32B 37/00 20130101; B32B 2307/102
20130101; B32B 37/153 20130101; E04C 2/246 20130101; B32B 37/24
20130101; B32B 2307/4026 20130101; B32B 2309/105 20130101; E04F
2201/0541 20130101; B32B 2250/03 20130101; Y10T 428/31989 20150401;
B32B 2250/40 20130101; B32B 2264/105 20130101; Y10T 428/31982
20150401; Y10T 428/269 20150115; B32B 2605/00 20130101; Y10T
428/31848 20150401; B32B 21/13 20130101; B32B 37/1027 20130101;
B32B 2419/00 20130101; E04F 15/02 20130101; Y10T 428/27 20150115;
B32B 2607/00 20130101; B32B 21/10 20130101; B32B 3/06 20130101;
Y10T 428/24901 20150115; B32B 2307/558 20130101; B32B 2260/021
20130101; Y10T 156/10 20150115; E04F 2201/0138 20130101; B32B
2307/718 20130101; B32B 2307/554 20130101; B32B 38/06 20130101;
B32B 2262/067 20130101; Y10T 428/24066 20150115; B32B 2307/75
20130101; Y10T 428/3167 20150401; B32B 38/145 20130101; Y10T
442/695 20150401; B32B 37/156 20130101; B32B 2309/04 20130101; B32B
2471/00 20130101; B44C 5/043 20130101; Y10T 428/253 20150115 |
International
Class: |
E04F 15/04 20060101
E04F015/04; B32B 3/06 20060101 B32B003/06; B32B 21/02 20060101
B32B021/02; B32B 37/10 20060101 B32B037/10; B32B 37/24 20060101
B32B037/24; E04C 2/24 20060101 E04C002/24; E04F 15/02 20060101
E04F015/02; B32B 21/13 20060101 B32B021/13; B32B 21/14 20060101
B32B021/14; B32B 37/00 20060101 B32B037/00; B32B 21/10 20060101
B32B021/10 |
Claims
1. (canceled)
2. A method of manufacturing a building panel comprising a core and
a surface layer, the method comprising a step of: applying a mix
comprising coated wood fibres, a second binder, color pigments, and
wear resistant particles on a first surface of the core; and curing
the mix by applying pressure and temperature to form the surface
layer on the core, wherein the coated wood fibres comprise wood
fibres pre-coated with a first binder, and wherein the coated wood
fibres are at least partially cured with the first binder.
3. The method according to claim 2, wherein the first binder is a
melamine resin.
4. The method according to claim 2, wherein the first binder is
urea formaldehyde resin.
5. The method according to claim 2, wherein the coated wood fibres
are obtained from recycled flooring.
6. The method according to claim 5, wherein the flooring is a
laminate flooring.
7. The method according to claim 5, wherein the flooring is a HDF
or HDF-based laminate flooring.
8. The method according to claim 5, wherein the coated wood fibres
are formed by mechanical cutting and separation of the flooring to
small wood fibres.
9. The method according to claim 2, wherein the coated wood fibers
are obtained from cutting and machines of edges of a wood-based
board.
10. The method according to claim 2, wherein the core comprises
coated wood fibres obtained from recycled HDF or HDF based laminate
flooring.
11. The method according to claim 2, wherein the method further
comprises applying a balancing layer on a second surface of the
core, the second surface being on an opposite side of the core from
the first surface.
12. The method according to claim 2, wherein the panel is a floor
panel.
13. The method according to claim 2, wherein the second binder is a
thermosetting or thermoplastic resin.
14. The method according to claim 2, wherein the coated wood fibres
comprise aluminum oxide or small melamine/paper flakes.
15. The method according to claim 2, wherein the building panel is
formed to a floor panel with mechanical locking systems at opposite
edges.
16. A method of manufacturing a building panel comprising a core
and a balancing layer, the method comprising a step of: applying a
mix comprising coated wood fibres, a second binder, color pigments,
and wear resistant particles on a second surface of the core; and
curing the mix by applying pressure and temperature to form the
balancing layer on the core, wherein the coated wood fibres
comprise wood fibres pre-coated with a first binder, and wherein
the coated wood fibres are at least partially cured with the first
binder.
17. The method according to claim 16, wherein the first binder is a
melamine resin.
18. The method according to claim 16, wherein the first binder is
urea formaldehyde resin.
19. The method according to claim 16, wherein the coated wood
fibres are obtained from recycled flooring.
20. The method according to claim 19, wherein the flooring is a
laminate flooring.
21. The method according to claim 19, wherein the flooring is a HDF
or HDF-based laminate flooring.
22. The method according to claim 19, wherein the coated wood
fibres are formed by mechanical cutting and separation of the
flooring to small wood fibres.
23. The method according to claim 16, wherein the coated wood
fibers are obtained from cutting and machines of edges of a
wood-based board.
24. The method according to claim 16, wherein the core comprises
coated wood fibres obtained from recycled HDF or HDF based laminate
flooring.
25. The method according to claim 16, wherein the core comprises a
surface layer on a first surface of the core, the first surface
being on an opposite side of the core from the second surface.
26. The method according to claim 16, wherein the panel is a floor
panel.
27. The method according to claim 16, wherein the second binder is
a thermosetting or thermoplastic resin.
28. The method according to claim 16, wherein the coated wood
fibres comprise aluminum oxide or small melamine/paper flakes.
29. The method according to claim 16, wherein the building panel is
formed to a floor panel with mechanical locking systems at opposite
edges.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S.
application Ser. No. 15/704,634, filed on Sep. 14, 2017, which is a
continuation of U.S. application Ser. No. 12/270,257, filed on Nov.
13, 2008, which claims the benefit of U.S. Provisional Application
No. 60/996,473, filed on 19 Nov. 2007, and to U.S. Provisional
Application No. 61/042,938, filed on 7 Apr. 2008. The entire
contents of each of U.S. application Ser. No. 15/704,634, U.S.
application Ser. No. 12/270,257, U.S. Provisional Application No.
60/996,473, and U.S. Provisional Application No. 61/042,938 are
hereby incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] The disclosure generally relates to the field of fibre-based
panels with wear resistant surfaces for building panels, preferably
floor panels. The disclosure relates to building panels with such
wear resistance surface and to production methods to produce such
panels.
FIELD OF APPLICATION
[0003] The present disclosure is particularly suitable for use in
floating floors, which are formed of floor panels with a wood fibre
core and a decorative wear resistant surface. The following
description of technique, problems of known systems and objects and
features of the invention will therefore, as a non-restrictive
example, be aimed above all at this field of application and in
particular at floorings which are similar to traditional floating
wood fibre based laminate floorings. The disclosure does not
exclude floors that are glued down to a sub floor.
[0004] It should be emphasized that the disclosure can be used as a
panel or as a surface layer, which is for example glued to a core.
The disclosure can also be used in applications as for example wall
panels, ceilings, and furniture components and similar. It is even
possible to produce components that could for example replace metal
or plastic components generally used in the industry, for example
automotive components. Such components could be produced with an
advanced shape and properties. Wear resistance, impact resistance,
friction and cost structure could be comparable or better than for
other conventional materials.
BACKGROUND
[0005] Wood fibre based direct pressed laminated flooring usually
comprises a core of a 6-12 mm fibre board, a 0.2 mm thick upper
decorative surface layer of laminate and a 0.1-0.2 mm thick lower
balancing layer of laminate, plastic, paper or like material.
[0006] A laminate surface generally comprise two paper sheets, a
0.1 mm thick printed decorative paper and a transparent 0.05-0.1 mm
thick overlay paper applied over the decorative paper and intended
to protect the decorative paper from abrasion. The print on the
decorative non-transparent paper is only some 0.01 mm thick. The
transparent overlay, which is made of refined .alpha.-cellulose
fibres, comprises small hard and transparent aluminium oxide
particles. The refined fibres are rather long, about 2-5 mm and
this gives the overlay paper the required strength. In order to
obtain the transparency, all natural resins that are present in the
virgin wood fibres, have been removed and the aluminium oxide
particles are applies as a very thin layer over the decorative
paper. The surface layer of a laminate floor is characterized in
that the decorative and wear properties are generally obtained with
two separate layers one over the other.
[0007] The printed decorative paper and the overlay are impregnated
with melamine resin and laminated to a wood fibre based core under
heat and pressure.
[0008] The small aluminium oxide particles could have a size in the
range of 20-100 microns. The particles could be incorporated in the
surface layer in several ways. For example they could be
incorporated in the pulp during the manufacturing of the overlay
paper. They could also be sprinkled on the wet lacquer during
impregnation procedure of the overlay or incorporated in the
lacquer used for impregnation of the overlay.
[0009] The wear layer could also be produced without a cellulose
overlay. In such a case melamine resin and aluminium oxide
particles are applied as a lacquered layer directly on the
decorative paper with similar methods as described above. Such a
wear layer is generally referred to as liquid overlay.
[0010] With this production method a very wear resistance surface
could be obtained and this type of surface is mainly used in
laminate floorings but it could also be used in furniture
components and similar applications. High quality laminate
floorings have a wear resistance of 4000-6000 revolutions, which
corresponds to the abrasion classes AC4 and AC5 measured with a
Taber Abraser according to ISO-standard.
[0011] It is also known that the wear resistance of a lacquered
wood surface could be improved considerably by incorporating
aluminium oxide particles in the transparent lacquer covering the
wood surface.
[0012] The most common core material used in laminate floorings is
fibreboard with high density and good stability usually called
HDF--High Density Fibreboard. Sometimes also MDF--Medium Density
Fibreboard--is used as core. Other core materials such as
particleboard are also used.
[0013] HDF is produced as follows: Roundwood such as for example
pine, larch or spruce are reduced to wood chips and then broken
down into fibres in a refiner. The fibres are thereafter mixed with
a binder and then subjected to high pressure and temperature to
form a board.
Definition of Some Terms
[0014] In the following text, the visible surface of the installed
floor panel is called "front side", while the opposite side of the
floor panel, facing the sub floor, is called "rear side". The
sheet-shaped material that comprises the major part of a panel and
provides the panel with the required stability is called "core".
When the core is coated with a surface layer closest to the front
side and preferably also a balancing layer closest to the rear
side, it forms a semi-manufacture, which is called "floor board" or
"floor element" in the case where the semi-manufacture, in a
subsequent operation, is divided into a plurality of floor
elements. When the floor elements are machined along their edges so
as to obtain their final shape with the joint system, they are
called "floor panels". By "surface layer" are meant all layers
which give the panel its decorative properties and its wear
resistance and which are applied to the core closest to the front
side covering preferably the entire front side of the floorboard.
By "decorative surface layer" is meant a layer, which is mainly
intended to give the floor its decorative appearance. "Wear layer"
relates to a layer, which is mainly adapted to improve the
durability of the front side.
[0015] By "horizontal plane" is meant a plane, which extends
parallel to the outer part of the surface layer. By "horizontally"
is meant parallel to the horizontal plane and by "vertically" is
meant perpendicularly to the horizontal plane. By "up" is meant
towards the front side and by "down" towards the rear side.
Known Technique and Problems Thereof
[0016] The wear resistant transparent layer which is used in many
floors, especially laminate floors, is generally placed on top of a
decorative printed paper or on top of a decorative printed surface
that is applied to a wood fibre based core. The decorative layer
will be destroyed when the thin and transparent protective wear
layer has been worn out.
[0017] The wear resistance of such floors is in many applications,
primarily in shops, hotels, restaurants and similar areas not
sufficient. The major reason is that people walk on the floor with
sand under their shoes. The decorative layer of a laminate floor is
often destroyed in a rather short period if time especially around
entrance areas or other areas of heavy traffic and wear such as
corridors. Laminate floors cannot reach the same wear resistance as
stone floors or a floor made of ceramic tiles.
[0018] Linoleum is a well-known floor covering which is made from
solidified linseed oil in combination with wood flour, cork dust,
limestone and colour pigments. It has a solid surface layer that
combines decorative features and wear resistance. This floor has
however several disadvantage. The impact and wear resistance is low
and it is difficult to create advanced designs. The production cost
is also rather high.
[0019] Several methods have been used to increase the wear
resistance of a laminate floor and they are all based on the
principle to include more wear resistant particles such as
aluminium oxide in the upper transparent layers over the printed
paper or the printed design. The major disadvantage of this method
is that the printed design becomes less clear since such thick
overlay creates a grey layer, which is not completely
transparent.
[0020] It is also known that several transparent overlays could be
pressed over the decorative paper to form a wear resistant surface
layer and that such multi overlays also could have a printed
pattern on their lower side. The designs could be coordinated such
that when an upper layer is worn out, a lower transparent layer
will protect the printed pattern. Due to uncontrolled swelling of
the overlay during impregnation it is very difficult to create an
attractive and wear resistant surface layer. Another disadvantage
is that such multi-layer overlays also give a grey and less
distinct design pattern, create more tension and a surface, which
is more sensitive to humidity changes.
[0021] Laminate floorings have many good properties and are more
cost efficient to produce than many other floor types such as wood
floorings and stone floor. Many improvements have been made since
the floor was invented in March 1977. The production is however
still very capital intensive and comprises many steps such as:
[0022] 1. Production of HDF. [0023] 2. Sanding of HDF in order to
create an even surface. [0024] 3. Production of decorative papers.
[0025] 4. Printing of decorative papers. [0026] 5. Production of
overlays. [0027] 6. Impregnation of decorative papers. [0028] 7.
Impregnation of overlays. [0029] 8. Pressing of decorative papers
and overlay to a HDF core and forming a floorboard. [0030] 9.
Dividing the floorboard into individual floor elements. [0031] 10.
Machining the edges of the floor panels to form locking
systems.
[0032] It would be a major advantage if some of these production
steps could be eliminated.
[0033] It is known that the printed paper in a laminate floor panel
could be replaced with digital or direct printing on the surface of
the HDF core. The quality of such direct printed floorings is
however still inferior to the print of the traditional decorative
paper used in laminate floorings and no major cost improvement has
been reached yet. The printed layer is protected with a traditional
overlay or a coating with a transparent wear resistant layer. The
wear resistance and impact resistance is generally inferior to
traditional laminate floorings.
[0034] Laminate floorings could be produced with very advanced
designs where a printed pattern is coordinated with an embossed
structure of the surface. The embossing is made during lamination
when the surface is pressed against a steel sheet with an embossed
structure. This requires that the steel sheet and the printed paper
are positioned accurately in a pre-determined position. Special
cameras must be used to obtain the positioning and uncontrolled
swelling of the decorative paper during impregnation creates major
problems. The depth of the embossing is limited by the paper that
could be damaged when the embossing is made with sharp edges or to
a depth, which exceeds a few tenths of a millimeter. Embossed
surfaces similar to a rough stone surface or a hand scraped wood
surface or deep grooves that could be used to make bevels in a
panel are not possible to make with the present pressing technology
and with a reasonable cost structure maintaining the present
technical properties and design.
[0035] Wood fibre based floorings similar to laminate floorings and
direct printed floorings could capture a considerable larger market
share if the wear and impact resistance could be increased, if one
or several production steps could be eliminated and if more
attractive designs could be obtained.
OBJECTS AND SUMMARY
[0036] An overall objective of embodiments of the disclosure is to
provide a building panel, preferably a floor panel, which has
better properties and/or cost structure than the known building
panels.
[0037] A first objective of embodiments of the disclosure is to
provide a fibre based panel, preferably a floor panel, with a wear
layer, which has a higher wear resistance and preferably also a
higher impact resistance than the present wood fibre based
floorings.
[0038] A second objective of embodiments of the disclosure is to
provide a fibre based flooring and a production method to produce
such flooring wherein the floor panel is produced in a more cost
effective way than the known floor types and where one of several
production steps are made in a more cost effective way or
completely eliminated.
[0039] A third objective of embodiments of the disclosure is to
provide a fibre based floor with new attractive design features
which preferably could be combined with high wear resistance and
cost effective production.
[0040] A fourth objective of embodiments of the disclosure is to
provide core materials and surface layers or combination of surface
layer and core which could be used to make panels, preferably floor
panels, with more favorable cost structure and/or design and/or
properties such as wear, impact and sound.
[0041] According to a first aspect of the disclosure a building
panel is provided comprising a surface layer and a core, which
comprises wood fibres. The surface layer comprises a substantially
homogenous mix of wood fibres, comprising natural resins, a binder
and wear resistant particles.
[0042] Embodiments of the disclosure offer several advantages over
known technology and especially over conventional laminate
floorings, for example: [0043] The wear resistant surface layer,
which is a homogenous mix, could be made much thicker and a wear
resistance, which is considerably higher, could be reached. [0044]
New and very advanced decorative effects could be obtained with
deep embossing and by separate decorative materials, which could be
incorporated into the homogenous surface layer and coordinated with
the embossing. [0045] An increased impact resistance could be
reached with a homogenous surface layer, which is thicker and has a
higher density. [0046] The homogenous surface layer could comprise
particles that have a positive impact on sound and moisture
properties. [0047] Production costs could be reduced since cheaper
materials could be used and several production steps could be
eliminated.
[0048] The wear resistant particles are preferably aluminium oxide
particles. Other suitable materials are for example silica or
silicon carbide. In general all materials with a hardness of
Rockwell C hardness HRC of 70 or more could be used.
[0049] Embodiments of the disclosure offer the advantage that the
wear resistant surface layer which is a homogenous mix and not
separate layers, could be made much thicker and a wear resistance,
which is 5-10 times better than in the present laminate floors
could be reached. It is possible to make a wear resistant surface
layer where abrasion of the surface will only reduce the thickness
with for example 0.10 mm for each 10,000 revolutions. 50,000
revolutions will only decrease the thickness with about 0.5 mm and
the wear resistance and the decorative properties will be
maintained. The wear resistant particles are preferably aluminium
oxide and the binder is preferably a synthetic thermosetting resin
such as for example a melamine resin.
[0050] Decorative effect could be obtained with wood fibres, other
types of fibres and/or decorative wear resistant particles only.
The decorative effects are however in the most preferable
embodiments obtained by colour pigments that are applied into the
homogenous surface layer.
[0051] Wood fibres in the surface layer comprising natural resins,
for example lignin, could be of the same type as used in HDF or
particleboard. They are therefore opaque and not transparent as in
an overlay paper sheet. The raw material price for such fibres is
much lower than for .alpha.-cellulose fibres where the natural
resins have been removed in the production process in order to
obtain transparency.
[0052] A particularly preferred embodiment is a floor panel
comprising a surface layer and a wood fibre based HDF or
particleboard core. The surface layer comprises a substantially
homogenous mix of wood fibres, comprising natural resins and of the
same type as used in HDF or particleboard, a binder of a synthetic
thermosetting resin, aluminium oxide particles and colour
pigments.
[0053] It could be mentioned as a non-restricting example that the
surface layer could comprise of for example about 25% (weight)
aluminium oxide, about 25% wood fibres, about 25% melamine
formaldehyde resin and about 25% colour pigments. The surface layer
could have a thickness which is for example in the range of 0.1
mm-3 mm or even more. Other combinations are of course also
possible. The melamine part could vary for example between 10-35%.
The content of the colour pigments could be very low for example
only about 0.1-5%. Wear resistant particles could be in the same
range and could for example vary from a few percent to 35% and even
higher. The mixture should be adapted to the desired properties and
cost structures. The binders contribute in general to give the
surface a high impact and moisture resistance but they are rather
costly. Some wear resistant particles are also rather costly. Wood
fibres and other fibres are in general rather cheap, especially if
they are derived from recycled material.
[0054] The wear resistant particles, for example aluminium oxide,
give only a very limited contribution to the impact resistance in a
laminate floor since they are only applied as a very thin layer
(0.1 mm) and the content is generally only about 10-30 gram/m2. The
disclosure gives however the possibility to use much more particles
in the solid homogenous surface layer and such particles could also
increase the impact resistance of the floor considerably. The wear
resistant particles are preferably distributed at random and fixed
in the surface layer by fibres and binders that surround them. It
could be mentioned as a non-restricted example that a 0.5-1.0 mm
surface layer according to the disclosure could comprise for
example 100-400 gram/m2 of wear resistant particles and even
higher. It is obvious that there is no lower limit and even rather
small amounts could be sufficient in some applications if such
particles are incorporated at least partly into the fibre
structure.
[0055] A wear resistant and decorative surface layer could be
formed in several alternative ways. It is possible to produce a
strong surface layer with small amounts of wear resistant particles
by for example increasing the content of the binder and/or
incorporating fibres, preferably wear resistant fibres that could
be used to replace a part of the wear resistant particles. Plastic
fibres, for example nylon fibres or mineral fibres such as glass
fibres, could improve the wear resistance considerably in a
homogenous surface layer material.
[0056] According to a second aspect of the disclosure a building
panel is provided comprising a surface layer connected to a core,
which comprises wood fibres. The surface layer, which gives the
panel decorative effects and wear resistance, is a homogenous layer
comprising parts of fibres, colour pigments, a binder and wear
resistant particles.
[0057] The wood fibres in the surface layer are according to this
second aspect completely or partly replaced with other fibres.
Preferable embodiments comprises fibres such as vegetable fibres
for example jute, linen, flax, cotton, hemp, bamboo, bagasse and
sisal and such fibres could be mixed with wear resistant particle,
for example aluminium oxide, to create a vegetable fibre based wear
resistant surface layer. Plastic fibres, for example nylon fibres
or mineral fibres such as glass fibres could also be used in
specific preferred embodiments. All fibres mentioned above could be
mixed together for example wood/bamboo, nylon/glass fibres etc.
Ceramic bubbles could be mixed with fibers in order to for example
increase the thermal insulation and acoustical absorption. Such
particles could also be non-flammable.
[0058] Wood fibres in the core could also partly or completely be
replaced with plastic fibres, mineral fibres or vegetable fibres in
the same way as described above for the surface layer.
[0059] Thermosetting binders are preferred but thermoplastic
binders could also be used. It is preferred to have the same type
of binder in the core and the surface in all embodiments of this
disclosure but combinations are not excluded for example a
thermosetting binder in the core and a thermoplastic binder in the
surface layer or the opposite.
[0060] A surface layer which comprises wear resistant particles
with high density, for example aluminium oxide, and where such
particles are distributed over a substantial thickness of the
surface layer, for example 0.2-1.0 mm, as described above could
have a density which is higher than the present laminate surfaces,
especially if such a layer also comprises a high degree of binders.
Such surface layer could have a density of 1500-2000 kg/m2 or even
higher and the impact resistance could be considerable higher than
in traditional laminate floorings where aluminium oxide is only
used in very thin well defined overlays with a thickness below 0.10
mm. The density could be lower but should preferably not be lower
than 1000 kg/m3. Sufficient impact resistance could be obtained
with a high density surface layer even with a rather soft core
material such as MDF or particleboard. The high density could also
give the floor a sound and feeling, which is similar to a real
stone floor.
[0061] The core could also be produced with high density especially
if small compact fibres are mixed with a high amount of binders and
pressed under high pressure.
[0062] It is obvious that all preferred embodiments of the first
aspect could be combined with the preferred embodiment of the
second aspect. This means for example that the same pressure,
pressing times, binders, fibres, wear resistant particles, material
compositions etc. could be used.
[0063] According to a third aspect of the disclosure a production
method is provided comprising the steps of: [0064] 1. Mixing
particles comprising fibres or fibres with binders, colour pigments
and wear resistant particles. [0065] 2. Bringing the particles or
the fibres, the colour pigments, the binders and the small wear
resistant particles under high pressure and temperature and forming
them to a building panel.
[0066] This production method could be used to produce all
embodiments of the disclosure.
[0067] The production method is in a preferred embodiment based on
a surface layer comprising wood fibres, aluminium oxide and a
thermosetting resin wherein the surface layer is formed and
connected to a HDF core or a particle board core in a pressing
operation such that it forms a floor board. This preferred
production method comprises the following steps: [0068] 1. Wood is
reduced to chips and then broken down into wood fibres. [0069] 2.
The wood fibres are mixed with a synthetic thermosetting resin,
colour pigments and aluminium oxide particles. [0070] 3. The wood
fibres, the colour pigments, the aluminium oxide particles and the
synthetic thermosetting resin are applied on a surface of a HDF or
particleboard core and subjected to high pressure and temperature
and formed to a homogenous and solid surface layer on the core such
that a floor board is formed.
[0071] A separate balancing layer of for example impregnated paper
could preferably also be applied on the rear side of the core
during the pressing.
[0072] Colour pigments are preferable to create an attractive
design. It is of course possible to use the production method to
produce the panel without colour pigments. Decorative effect could
be obtained with different fibres or wear resistant particles only.
Aluminium oxide could for example be produced in different
colors.
[0073] Seven of the ten production steps (2-8 above) could be
eliminated since paper is not used and lamination is not required.
Printing could be made in line with the production of the
floorboard. The binder is preferably a melamine-formaldehyde or
urea-formaldehyde or phenol-formaldehyde resin or combinations of
these resins. The pressure is preferably about 300N-800N/cm2 and
the temperature could be 120-220 degrees C. The pressing time could
vary for example from 20 seconds to 5 minutes. It is possible to
use very short pressing times, for example about 10 seconds or
shorter, especially in embodiments where a rather thin fibre layer
is applied on an HDF core before pressing. Thermoplastic binders
such as PVC, PE, PP, etc. could also be used. Other possibilities
are for example natural resins such as sugar or lignin.
[0074] The production method could preferably comprise an
intermediate pressing step where the fibres are partly compressed
but not cured. Printing or application of decorative materials
could be made between the intermediate and the final pressing.
[0075] Decorative features could also be applied after the curing.
Laser could for example be used to engrave the surface and
decorative grooves could be made such that surface material is
removed to a lower part of the surface, which comprises a layer
with a different colour or design than the upper surface portion.
Further heat and pressure could be applied to change the colour or
to create further embossing of the surface.
[0076] Laser could also be used prior to final pressing in order to
create decorative patterns and effects such as dark lines or spots
that for example are used to copy wood or stone.
[0077] The method could be used to produce a whole floorboard. The
method could also be used to produce an upper and/or lower layer,
which is applied on a known fibreboard or particleboard core,
preferably a HDF core. The method could also be used to produce
individual floor elements and even the finished floor panels where
the edges and even parts or the whole locking system could be
formed during pressing.
[0078] According to one preferred embodiment, the whole panel is
made in a continuous production line where fibres, binders, colour
pigments and wear resistant particles or fibres are applied in
preferably at least three layers with different material
compositions in order to form a panel with a core and a surface
layer. A preferred embodiment where the surface layer and the core
are integrally formed, continuously or discontinuously, in
substantially the same pressing operation is referred to as
"integrally formed panel" or IFP. The lower layer or part could be
a balancing layer comprising substantially wood fibres and binders
only, which are adapted to balance the surface layer. The balancing
layer could also be applied as a separate pre-fabricated material
that could be fused to the core during pressing. It could also be
used as a carrier for the fibres when they are transported into a
press. The middle layer or middle part is preferably a core layer
comprising wood fibres and binders only and the upper layer is a
surface layer comprising wood fibres, colour pigments and wear
resistant particles or chemicals.
[0079] The layers are preferably applied and transported on a
conveyor belt and optionally pre-pressed from an initial thickness
of for example 30-50 mm to an intermediate thickness of for example
10-20 mm. A decorative pattern could then be applied in line on the
pre-pressed surface with for example an ink jet digital device
which allows the ink to penetrate into the pre pressed surface. The
board is finally pressed under heat and pressure to a thickness of
for example 4-10 mm in preferably a continuous pressing operation
at the end of the production line where optionally a sanding of the
lower balancing layer could be made in order to obtain an accurate
thickness if necessary.
[0080] An IFP panel could also be produced in a production line
comprising a discontinuous press of the conventional type generally
used in laminate floor production. The core, the surface layer and
preferably also the balancing layer are formed and connected to
each other in the discontinuous press.
[0081] The production could preferably also be made in a two-step
process where the production steps to obtain a core and a surface
layer are performed in two separate operations. This production
method is referred to as "surface on core" production or SOC. A
core of a wood fibre based board such as for example HDF, MDF,
particleboard, OSB, plywood and similar sheet materials could be
produced in the conventional way. A lower and/or upper layer,
comprising the surface layer and optionally also the balancing
layer, is thereafter applied to the core with scattering equipment
and this could be integrated with the steps that give the surface
its decorative properties. A separate balance layer could be
applied in a separate production step. The core with preferably the
upper and lower layers is thereafter pressed in a continuous or
discontinuous press such that the upper surface layer and
optionally even the balancing layer are cured and laminated to the
pre-fabricated core. All types of core materials could be used and
the method is very suitable even for soft core materials and core
materials with rough surface portions. The decorative surface layer
could fill up irregular surface portions in the core and reinforce
the core such that an impact resistant panel is obtained with any
kind of decorative surface structures. This decorative surface is
not affected by the core surface as in traditional laminate and
wood veneer floorings.
[0082] The core material and an upper surface layer or lower
balancing layer could according to a preferred embodiment also be
produced separately in three production steps and the separate
layers could be connected to the core by for example gluing.
[0083] A separate wood fibre or fibre layer, which could be used
primarily as a surface layer but of course also as a balancing
layer, hereafter referred to as "separate surface layer" or SSL,
could be produced continuously or discontinuous in thickness of for
example 0.3-2 mm. Such a surface layer could be used to replace
laminate sheets, wood veneer or wood layers in laminate and wood
floorings with for example a core of HDF, MDF, particle board,
plywood, lamella wood core and similar. The surface layer could
have a high density and impact resistance even if it is combined
with rather soft core materials.
[0084] All these three basic embodiments, IFP, SOC and SSL could be
used to produce a floor according to the disclosure. Such floor is
in this application generally referred to as a Fibre Composite
Floor or FCF. It could be produced as described above with
continuous or discontinuous presses and the production steps could
be combined in parts. It is for example possible to produce the
core and the surface layer or the core and the balancing layer in a
integrally formed operation similar to IFP and to apply a balancing
layer or surface layer in a separate production step similar to
SOC. A pre curing and a final curing with various intermediate
steps are also possible to use.
[0085] The decorative properties could be obtained in several ways.
The surface is in one embodiment made decorative by colour
pigments, which preferably are mixed into wood fibres. The whole
panel could be colored. Alternatively colour pigments could be
mixed with for example wood fibres, binders and wear resistant
particles in the upper layer. A printed pattern could be provided
on the basic colour. The printing should be made preferably before
the final pressing and curing operation and this will allow the
print to penetrate deep into the upper fibre layer. The print could
be applied in such a way that it extends a considerable distance,
for example 0.1-1.0 mm, into the upper fibre layer after pressing.
Vacuum could be used to facilitate and to guide the penetration of
the print into the basic fibres. Such a print could create very
accurate copies of stone and wood products and it will maintain its
pattern even when the surface layer has been worn down
considerably. A very durable, decorative and wear resistant surface
could be created in a very cost effective way. Fine and
well-distributed fibres in the surface layer make it possible to
create very distinct and accurate wear resistant printed
patterns.
[0086] The decorative effects could also be obtained with rather
soft separate materials, for example different types of fibres,
chips or particles of wood, textiles, plastic, cork, and similar
which optionally could be mixed with colour pigments and applied by
for example scattering or extrusion as a protruding pattern on the
basic fibre surface before the final pressing.
[0087] Fibres could also be used to improve mechanical properties.
Mineral fibres such as for example glass fibres could increase the
strength and flexibility and improve resistance against heat and
fire. Natural fibres could also have a positive impact on the
properties. Variations in the fibre orientations could be used to
increase the decorative effects.
[0088] Separate materials applied on the basic surface will after
pressing penetrate into the basic surface fibres. The penetration
could be controlled very accurately. A hard material composition
will penetrate deep into the softer basic fibres. A softer separate
material will be more compressed and distributed over a larger
surface area. The separate materials should preferably have a
different size and/or structure and/or orientation and/or optical
effects than the basic fibres and they will automatically create a
perfect fit between a desired pattern and a surface structure. The
design effects could be even more pronounced if the separate
materials have different wear resistance than the basic fibre
structure. The surface could be brushed and the different fibre
structures will be more visible as in real wood or stone floors. A
similar effect could be obtained if the printing paint comprises
wear resistant particles, which are applied locally during the
printing process. The surface could comprise particles that could
swell, expand or shrink after pressing and thereby create an uneven
or embossed surface. All these design effects could be maintained
when the surface is subject to considerable wear during a long
period of time since they extend deep into the surface layer.
Repetition effects of a printed pattern could be avoided.
[0089] Special hard wear resistant and decorative non wood fibre
based materials could also be incorporated into the surface for
example synthetic diamond powder or diamond particles preferably
with a size of 0.01-0.10 mm. Such diamond particles could also
increase the wear resistance and improve friction properties of the
floor. Other alternatives are metal powder or flakes, stone powder,
ceramic powder or particles, sand and other similar known
decorative materials.
[0090] Nano particles could also be incorporated and this could for
example be used to give the surface improved properties related to
glossiness, cleanability, UV stability, friction, wear resistance
etc.
[0091] Traditional methods where the surface is pressed against an
embossed steel sheet or belt or a paper matrix in order to create
decorative effects could also be used. The advantage is that the
embossing could be made much deeper that in traditional laminate
floorings since there is no paper that could be damaged during
lamination. Grout lines, grooves and bevels at the edges or in the
main surface parts could be made and such structures could have the
same or different design type as the main surface. The grooves
could be partly or completely filled with separate materials as
described above.
[0092] All these design effects could be combined. The invention
does not exclude additional transparent or non-transparent layers,
coating or similar over the basic fibre structure. The design
effects could also be used independently in a fibre panel that does
not comprise wear resistant particles or colour pigments. In this
case the wear resistance could be created with wood fibres and
binders only.
[0093] All these design effects are preferably created, contrary to
the known technology, by methods where prints and colors penetrate
deep into a preferably pre formed semi-finished surface layer or
where separate decorative materials are incorporated into or
applied on the main surface layer.
[0094] It is also possible, according to embodiments of the
disclosure, to create a very glossy surface similar to present
laminated or lacquered surfaces. The disclosure offers the
advantages that such surface could be polished or brushed in a
further production step to an even more attractive surface or it
could be polished several times after installation with for example
brushes comprising hard particles for example diamond powder. The
original glossy surface could be recreated even after several years
of hard wear.
[0095] Special decorative effects and mechanical properties could
be obtained with a surface layer comprising fibres of different
wood types or combinations of two or more wood species for example
any combination of oak, ash, maple, beach, pine, spruce, birch,
merbau or similar. These different wood fibres could also be
colored, heat-treated or modified in similar ways before they are
applied as a surface layer.
[0096] Advanced decorative effects could be obtained with fibres
and decorative particles that could be applied and positioned
electrostatically. This method makes it possible for example to
position and orient wood fibres and to create a structure similar
to a wood veneer. Gravity and airflows could also be used to
distribute fibres and particles in a controlled way.
[0097] Cork material in the form of small particles or dust could
also be used to partly or completely replace wood fibers in all
embodiments of the disclosure.
[0098] It is known that cork could be used as a surface or backing
layer in a floorboard. The layers could be made from granules of
cork that are glued or they could be in the form of a cork veneer.
The cork is used mainly to reduce sound but also for decorative
purposes. It is also known that cork granules could be mixed into
for example concrete in order to obtain low thermal conductivity,
low density or good energy absorption. It is not known that cork
dust could be mixed with a binder, preferably a synthetic
thermosetting binder, and wear resistant particles to form a
surface layer in a floorboard.
[0099] According to a fourth aspect of the disclosure a building
panel is provided comprising a surface layer and a core, which
comprises wood fibres or cork particles. The surface layer
comprises a substantially homogenous mix of cork particles, a
synthetic binder and wear resistant particles.
[0100] The core could be a traditional wood fibre based core, for
example HDF or similar or it could be a core comprising partly or
completely cork particles and a binder, preferably a thermosetting
binder. Colour pigments could be included.
[0101] A particularly preferred embodiment is a floor panel
comprising a surface layer and a core, which comprises wood fibres
or cork particles. The surface layer comprises a substantially
homogenous mix of cork particles, comprising natural resins, a
synthetic thermosetting binder and wear resistant particles of
aluminium oxide.
[0102] The density of the cork surface layer is preferably 800-1400
kg/m3 and the density of the core could be 600-1000/m3.
[0103] Embodiments of the disclosure offer the advantage that the
surface layer could be made more flexible and softer than in
traditional laminate floorings and this could be combined with a
maintained or even improved wear and impact resistance. This could
also result in a more attractive sound level and lower thermal
conductivity. The result could be a more silent and warmer
floor.
[0104] A floor panel comprising cork particles could be produced
according to the same three basic embodiments, IFP, SOC and SSL as
described above.
[0105] The principles of the disclosure could also be used to
produce a core comprising cork that could be used to replace a
traditional wood fibre based core for example a HDF panel.
[0106] It is known that cork chips with a size of 2-5 mm could be
glued together with very low pressure to panel with a density that
does not exceed 300 kg/m3. It is not known however that very small
cork particles, for example smaller than 1.0 mm, could be mixed
with a thermosetting binder and pressed together with high pressure
to form a high-density panel that could for example be used as a
core material in a floor panel.
[0107] According to a fifth aspect of the disclosure a building
panel is provided comprising small cork particles and a
thermosetting binder that are pressed together to a panel with a
density exceeding 600 kg/m3. Such a cork particle based core could
be used together with a surface layer comprising cork particles or
a surface layer according to the first and second aspects of the
disclosure but it could also be used as a core in a floor with
traditional surface layers.
[0108] A cork core or surface layer could have properties, for
example moisture resistance, shearing strength, density and impact
resistance similar to or even better than normal HDF material and
it is possible to form a strong and a high quality locking system
in the cork core edge. The flexibility of the cork particles makes
it possible to reach a high impact resistance. The properties are
mainly achieved by mixing a thermosetting resin, for example
melamine in powder form with small cork particles, preferably with
a size of a few tenths of a millimeter or even smaller down to some
hundredths of a millimeter, which are thereafter pressed with a
pressure of about 300-400 N/cm2 and a temperature of 140-180
degrees C.
[0109] The cork core could be used in combination with known
surface materials such as laminate, resilient surfaces, fibre based
surfaces, wood, wood veneer, linoleum, cork veneer, wall to wall
carpets and similar. Several advantages could be reached. A thin
surface layer, for example a wood veneer could be applied, prior to
pressing, on a sub layer comprising cork particles and binders.
Pressing could take place against a press plate, which could create
a deep embossing, or deep grooves. The thin surface layer will be
formed and laminated to the sub layer. The thin surface layer will
not be damaged since the cork particles will be compressed and
formed according to the structure of the press plate. This forming
technology could also be used in a panel where the sub layer
comprises wood fibers or other type of fibres that could be formed
by pressing.
[0110] A combination core or panel could also be produced with
different layers that comprise only cork particles or wood fibre
particles or a mixture of wood fibres and cork particles.
[0111] It is preferred in all embodiments to use a dry process
where the different materials and mixtures of different materials
such as fibres, wear resistant particles, binders and colour
pigments are distributed and scattered in a dry form. A liquid or
semi liquid process where for instance the binder is mixed into the
fibres or particles in liquid form is however not excluded.
Scattering could be made with several stations comprising embossed
or engraved rollers and brushes that could apply one or several
layers of preferably dry materials.
[0112] All embodiments with and without wear resistant particles
could be used to make panels, which could be applied vertically on
a wall as wall panels in interior or exterior applications. Such
panels could have a mechanical locking system on long edges that is
possible to lock with angling and on short edges a locking system
with for example a flexible tongue that allows vertical folding as
described in for example WO 2006/043893.
BRIEF DESCRIPTION OF THE DRAWINGS
[0113] The disclosure will in the following be described in
connection to preferred embodiments and in greater detail with
reference to the appended exemplary drawings, wherein
[0114] FIGS. 1a-1d illustrate a conventional laminate floor
panel;
[0115] FIGS. 2a-d Illustrate surface layers in conventional floor
panels;
[0116] FIGS. 3a-d Illustrate a floor panel according to an
embodiment of the disclosure;
[0117] FIGS. 4a-4b illustrate production methods according to a
preferred embodiment of the disclosure;
[0118] FIGS. 5a-5c illustrate a production method according to a
preferred embodiment of the disclosure and methods to create a
decorative surface;
[0119] FIGS. 6a-6f illustrate preferred methods to create
decorative effect;
[0120] FIGS. 7a-7d illustrate a floor panel and methods to produce
an edge portion;
[0121] FIGS. 8a-8d illustrate a panel surface and a method to form
such surfaces;
[0122] FIGS. 9a-b illustrate a scattering station;
[0123] FIGS. 10a-c illustrate a method to form a surface layer;
[0124] FIGS. 11a-c illustrate methods to create decorative effect
on the surface layer;
[0125] FIGS. 12a-e illustrate discontinuous pressing and forming of
a surface layer on a prefabricated core;
[0126] FIGS. 13a-k illustrate locking of a floor panel with a
decorative surface on front and rear side;
[0127] FIGS. 14a-e illustrate a method to create advanced patterns
in floor panels made from floorboards with different designs;
[0128] FIGS. 15a-d illustrate preferred embodiments of floor panels
made from floor boards with different designs;
[0129] FIGS. 16a-e illustrate a method to obtain in register
embossing of a surface layer; and
[0130] FIGS. 17a-f illustrate in detail an example of a preferred
embodiment of an integrally formed panel.
DETAILED DESCRIPTION OF EMBODIMENTS
[0131] FIG. 1a shows a laminated floor panel 1 according to known
technology comprising a surface layer 5, a core 6 and a balancing
layer 7.
[0132] FIG. 1c shows the surface layer 5. It has an upper wear
layer 13 of a transparent material with great wearing strength.
Such a wear layer comprises generally a transparent paper (overlay)
impregnated with melamine resin and with aluminium oxide particles
12 added. Aluminium oxide particles are generally positioned in the
lower part of the overlay in order to protect the press plates from
wear during pressing. A decorative layer 10, comprising of paper
with a printed pattern 11 is impregnated with melamine resin and
placed under this transparent wear layer 13. The wear layer 13 and
the decorative layer 10 are laminated to the core, generally a
fibre based core such as HDF, under pressure and heat to an about
0.2 mm thick surface layer 5.
[0133] FIG. 1b shows the balancing layer 7 that generally also is a
melamine-impregnated paper. This balancing layer keeps the floor
panel flat when humidity varies over time. The transparent wear
layer is generally 0.05-0.10 mm thick. The decorative printed
pattern 11 will be destroyed when the wear layer is worn out.
[0134] FIG. 1d shows in detail the upper surface part of a
conventional laminate floor as explained above. The aluminium oxide
particles 12, which are transparent, are included in the pulp
during the production of the transparent overlay 13.
[0135] FIG. 2a shows a known surface layer with multiple overlays
13 that have a coordinated print on the lower side in order to
improve wear properties. The layers are also in this surface layer
placed over a decorative layer 10.
[0136] FIG. 2b shows a known overlay, which generally is
semitransparent, colored with colour pigments 15 and placed on a
decorative layer 10.
[0137] All overlays are made of refined .alpha.-cellulose fibres.
In order to obtain the transparency, all natural resins that are
present in the virgin wood fibres have been removed. The known
surface in a laminate floor is in all embodiments made up of
well-defined paper layers with constant thickness. Separate layers
are used to accomplish the decorative properties and the wear
properties. The total thickness of all wear resistant layers does
not exceed 0.2 mm. There is a clear distinction between the refined
and expensive fibres that are used in the upper surface layers and
the non-refined low cost wood fibres that are used in the core.
[0138] FIG. 2c shows a known direct print on a HDF panel. A base
colour 16 comprising colour pigments 15 is applied on a core 6. A
print 11 is applied on the base colour and protected against wear
by a transparent varnish 18 and in some applications even with a
top coating layer 17 that could comprise aluminium oxide. Such a
surface layer is colour based and no fibres are used.
[0139] FIG. 2d shows a known colored HDF panel where colour
pigments are 15 are included in the core. The surface is covered
with a transparent top coating layer 17. The wear and impact
resistance of such a panel is low.
[0140] FIG. 3a shows a floor panel 1 according to one embodiment of
the disclosure. A panel 1 is provided with a wood fibre based core
6, a homogenous non-transparent decorative surface layer 5 and
preferably a balancing layer 7. The panel 1 is integrally formed in
a production process where the surface layer, the core and the
balancing layer are formed in the same pressing operation.
[0141] FIG. 3b shows the surface layer 5. It comprises a mixture of
wood fibres 14, small hard wear resistant particles 12, 12' and a
binder 19. Preferably the wood fibres are unrefined, of the same
type as used in HDF and particleboard and they comprise natural
resins such as lignin. The wear resistant particles (12,12') are
preferably aluminium oxide particles. Other suitable materials are
for example silica or silicon carbide. Diamond crystals or powder,
could also be added into the surface layer. In general all
materials with a hardness of Rockwell C hardness HRC of 70 or more
could be used and they do not have to be transparent. A mixture of
two or more materials could be used. The connection 34 between the
core 6 and the surface layer 5 is not a distinct layer, as can be
seen in FIG. 3b due to the fact that fibres of the two layers are
mixed are fused together. This gives a very strong connection
between the core and the surface layer.
[0142] The surface layer comprises preferably also colour pigments
15 or other decorative materials or chemicals.
[0143] Embodiments of the disclosure offer the advantage that the
wear resistant surface layer 5 could be made much thicker than in
the known floor panels. The thickness of the wear resistant and
decorative surface layer could vary from for example 0.1-0.2 mm to
for example 2-4 mm or even more. Wear resistance with maintained
decorative properties could be extremely high, for example in the
region of 100,000 revolutions and more in a surface layer that is
about 1.0 mm thick.
[0144] Such a panel could be used as a floor panel but also as a
component in a machine, car etc. where a high wear resistance is
required and complex injection moulded or extruded components could
be formed which also could be reinforced with for example glass
fibres.
[0145] The surface layer according to a preferred embodiment of the
disclosure comprises a vertical portion P with a first upper
horizontal plane H1, located in the upper part of the surface layer
that comprises a first wear resistant particle 12. It has a second
intermediate horizontal plane H2, located under the first wear
resistant particle 12 that comprises wood fibres with natural
resins. It has a third lower horizontal plane H3, located under the
second horizontal plane H2 that also comprises a second wear
resistant particle 12. The fibres and wear resistant particles
could preferably be mixed with colour pigments. Such an embodiment
will give a very wear resistant surface layer that will maintain
its decorative properties. The surface will be undamaged when the
abrasion has removed the first upper fibres to the second
horizontal plane H2. Only about 0.1 mm of the surface will be
removed. The abrasion will then remove material to the second
horizontal plane H2 and the surface will still maintain its
decorative properties. The abrasion must remove materials to the
third horizontal plane and only then, provided that there are no
further horizontal planes comprising wear resistant particles or
colour pigments, will the surface change its decorative properties.
The surface layer could comprise many horizontal planes adjacent to
each other and located at different distances from the front side
of the panel, for example 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm
etc. and they could comprise wear resistant particles or wood
fibres. Embodiments of the disclosure offer the advantage that a
wear resistance, which is considerably better, for example 5-10
times better than in the present laminate floors, could be reached.
Abrasion of the surface will only reduce the thickness of the
surface layer. The wear resistance and the decorative properties
will be completely or essentially maintained or changed in a
controlled and pre-determined way.
[0146] A preferable binder is melamine or urea formaldehyde resin.
Any other binder, preferably synthetic thermosetting resins, could
be used.
[0147] FIG. 3c show that a balancing layer 7 comprising preferably
wood fibres 14'' and a binder could be provided on the lower side
of the floor panel. The fibres, the binder and also the pressing
temperature should be adapted in an appropriate way to balance the
surface layer and to keep the panel flat. The balancing layer 7 is
preferably pressed with a higher temperature for example 5-20
degrees higher than the surface layer 5
[0148] It could be mentioned as a non-restricting example that the
surface layer could comprise of for example 25% (weight) aluminium
oxide, 25% wood fibres, 25% melamine resin and 25% colour pigments.
The surface layer could have a thickness which is for example in
the range of 0.1 mm-3 mm or even more. The most preferable
thickness is 0.5-1.5 mm.
[0149] FIG. 3d show a panel where the surface layer 5 has been
formed on a core 6 that has been produced in a prior separate
operation according to the SOC principle. There is a distinct
connection 34 between the core 6 and the surface layer 5. The
connection 34 could be very strong since binders 19 from the
surface layer 5 penetrate into the upper part of the core 6,
especially if the core is HDF or a wood based panel such as for
example particle board. The binders 19 in the surface layer 5 could
be specially adapted to penetrate and reinforce the upper parts of
the core in order to for example increase the moisture resistance.
Different binders or binder contents could be used in the upper and
lower parts of the surface layer 5.
[0150] FIGS. 4a, 4b and 5a schematically show preferred production
methods, which could be used to produce a fibre based panel. The
methods are described schematically and with the surface layer as
the upper layer. It is obvious that the production could take place
with the surface layer as a lower layer.
[0151] FIG. 4a shows production of a panel, preferably a floor
panel according to the preferred IFP principle. A scattering
station is used to apply a first layer 7, comprising the balancing
layer, on a conveyor 20. A second layer 6 comprising the core layer
is applied on the balancing layer in the same way. These two layers
comprise preferably wood fibres and a binder only. A third layer,
the surface layer 5, is applied by the scattering station on the
core layer 6. The surface layer 5 comprises preferably wood fibres,
a binder and wear resistant particles. The surface layer 5
comprises preferably also a colour pigment that gives the surface
layer a basic colour. The production method could preferably
comprise an intermediate pressing step, where the wood fibres are
partly compressed with a roller 21 or with continuous pressing
equipment or a similar device. The fibres are preferably not cured,
at least not completely, at this intermediate production step.
[0152] The scattering station 60 could comprise several scattering
units 60a, 60b, 60c, one for each material composition. An advanced
production line could comprise up to ten scattering units and even
more.
[0153] Printing, coloring and similar design effects on the surface
with for example an ink jet printer 22 or similar production
equipment that gives the surface layer 5 decorative features could
be used in line with the production of the floorboard. Printing is
preferably made on a pre-pressed surface prior to the final
pressing.
[0154] A scattering station could also be used after the pre
pressing in order to for example apply additional decorative
particles. A second pre pressing and even further applications of
decorative materials could be made prior to the final pressing.
[0155] The pre pressed layers are after printing, if such
production step is used, pressed under heat and pressure and the
fibres and the wear resistant particles are bonded together with
the binder, which cures under heat and pressure. A panel with a
hard and decorative surface layer is obtained.
[0156] Continuous pressing is preferred but discontinuous presses
with one or several openings could also be used.
[0157] Pressing could take place against an embossed pressure
matrix such as a steel belt 23, an embossed sheet or a paper-based
embossed matrix in order to create an embossed surface that
optionally could be coordinated with the surface design. High
quality coordinated design and embossing could be obtained with an
integrated pressing and design method which is not used in the
flooring industry since all such design features are based on two
separate steps of printing and pressing.
[0158] According to embodiments of the disclosure an integrated
pressing and design "stamp" method could be used whereby an
embossed pressure matrix comprising protrusions, which are covered
with a selected paint, for example with a rubber roller that
applies the paint only on the protrusions and not on the matrix
parts located at lower portions between the protrusions, could be
used. During pressing, it is possible to apply the selected paint
only in the sections of the surface that are pressed below the top
parts of the surface layer and a perfect coordinated design and
structure could be obtained. The "stamp" method is described more
in detail in FIGS. 16a-e. The paint and the pressing could be
chosen such that the paint penetrates into the fibre structure
during the initial part of the press cycle. The same method could
be used to apply other materials than paint for example special
fibres or particles on protrusions located on a pressing matrix and
to apply them into deeper structures than the top parts of the
surface.
[0159] The binding agent is preferably a melamine-formaldehyde
resin. The pressure is preferably about 300N-800N/cm2 and the
temperature could be 120-220 degrees C. The pressing time could
vary for example from 20 seconds to 5 minutes depending on the
production speed, panel thickness, binders etc. The density of the
floorboard is preferably 700-1000 kg/m3. It is possible to produce
very moisture and impact resistant floorboards with a density of
1000-1500 kg/m3. The surface layer may comprise or consist of wood
fibers that are essentially smaller than 1 mm. The surface layer
may comprise or consist of wood fibers in powder form that are
essentially smaller than 0.5 mm. The surface layer comprises
preferably or consists of fibres in wood powder form with particles
which are in the range of about 0.1-0.3 mm or even smaller. The
fibre particles in the core part could be 0.1-1.0 mm or even
larger.
[0160] A particularly high quality surface layer 5 could be
achieved if the wood fibres, which are mixed with the binder,
colour pigments and wear resistant particles, are already pre
coated and fully or partly pre cured with a binder, for example a
melamine or urea formaldehyde resin, or pressed and then separated
mechanically into wood fibre powder or wood fibre chips which are
preferably smaller and more compact than the original wood fibres.
Such a fibre composition is especially well suited to be mixed with
wear resistant particles and could create a compact and
well-defined base for the printing operation. The wear resistant
particles could be evenly spread over the whole surface layer and a
high wear and scratch resistance could be reached. Such coated
fibres could be obtained from recycled HDF or HDF based laminate
floorings, which could be mechanically cut and separated to small
wood fibre chips and/or wood fibres. The chips and fibres could be
used in all layers (5, 6, 7) even if they comprise aluminium oxide
or small melamine/paper flakes. The wood fibres could also be
separated from the melamine and paper particles and used as
melamine coated fibres in the surface 5 and/or in the core 6 and/or
the balancing layer 7.
[0161] FIG. 4b shows substantially the same production method,
which in this preferred embodiment is used to produce a SOC panel.
A balancing layer 7 is applied on a conveyor. The balancing layer
could be a wood fibre based layer as described above or a
traditional balancing paper used in conventional laminate flooring
production. A pre-fabricated core 6, for example a HDF or a
particleboard or any other type of board is placed over the
balancing layer. A surface layer 5 is applied with a scattering
station 60 on the core, according to the same method as described
above, and the upper and lower layers are connected to the core in
a press such that a panel is formed with a surface layer 5, a core
6 and a balancing layer 7.
[0162] The balancing layer 7 could be decorative and could comprise
wear resistant particles. This means that a panel according to the
disclosure could have a surface layer 5 and 5' on each side. Such
surface layers could preferably have different designs and this
will reduce the number of articles that have to be transported and
stored. Embodiments of the disclosure are very suitable for such
double-sided panels since the cost for providing the rear side with
a decorative layer is very limited. Mechanical locking systems
could be adapted to allow locking of such panels preferably with
horizontal or vertical snapping.
[0163] FIG. 5a shows the SSL principle where a panel is formed
which could be used as a separate surface layer. The production
equipment is in this case used in the same basic way as in the
other two methods described above. The main difference is that the
floor board 3 is a surface layer 5 with preferably a thickness of
about 0.5-3 mm. This surface layer could be connected, preferably
with glue, to any type of core material.
[0164] Decorative features could be obtained in many alternative
ways. In the most basic embodiment the surface could comprise
substantially only wood fibres and wear resistant particles. A
design with one basic colour only could be sufficient and in such a
case colour pigments are mixed with the wood fibres and no
intermediate pre pressing is needed in order to form a base
structure for further design steps. Pre pressing could however be
used for other purposes as will be explained in the text below.
[0165] FIG. 5b shows that a decorative pattern could be obtained by
mixing fibres with different colors 30, 31 and/or different fibre
structures, fibre sizes, fibre types etc.
[0166] FIG. 5c shows an ink jet spray head 24 that could be used to
apply a print 32 or a pattern similar to a print on a preferably
pre pressed surface. The ink penetrates into the fibres prior to
pressing and could be positioned deep into the cured surface after
pressing. Ink or colour particles could be applied for example with
a depth under the upper part of the surface of 0.1-1.0 mm or even
more. The ink should preferable penetrate to a level below the
upper wear resistant particles.
[0167] FIG. 6a shows that for example an extruder 25 with an
extruding head 26 could apply separate extruded fibres 33, with a
different colour and/or structure and/or density and/or wear
resistant properties, on the basic fibre layer. The extrude fibres
are preferably mixed with a binder and optionally also with wear
resistant particles.
[0168] FIG. 6b shows that the separate fibres 33 could be pressed
and bonded into the surface layer 5.
[0169] FIG. 6c shows that the separate fibres 35 could be applied
with a lower wear resistance then the basic fibre surface. The
surface could be brushed and this will remove a part of the upper
surface of the separate fibres 35 and a decorative groove will be
obtained. This will give a perfect match between the structure and
the colored design.
[0170] FIG. 6d shows that other separate materials such as flakes
36 of wood, metal, plastic etc. could be used to give the surface
decorative properties and these separate materials could be pressed
into the basic wood fibre surface.
[0171] FIG. 6e shows that pressing a matrix to the surface could
create grooves, bevels, grout lines and similar. Such embossing
could be made much deeper than in traditional laminate floorings
where the paper will be damaged. Embossing with a depth of for
example 1-2 mm or even more could easily be obtained.
[0172] FIG. 6f shows that a surface design could be obtained with
for example wood fibres, preferably essentially individual fibres
or clusters of individual fibres that are located in patterns on
the surface. They could be applied in several layers, which are
coordinated such that they build up a material layer similar to
real wood.
[0173] All the above described methods to create design effects
could be used in IFP, SOC and SLL embodiments with or without a
pre-pressing operation.
[0174] FIG. 7a shows a panel according to an embodiment of the
disclosure. It comprises a surface layer 5 which is produced
according to an embodiment of the disclosure and which is glued or
laminated to a known core material 6. A balancing layer 7 is
applied at the rear side as shown in FIG. 7b. The floor board 3 is
produced according to the IFP, SOC or SSL principles described
above. FIG. 7c shows the floor board after it has been cut into
several floor elements 2. FIG. 7d show a floor element which have
been formed to a floor panel 1 with mechanical locking systems 4,
4' at the long edges. A mechanical locking system is generally also
formed on the short edges. All known locking systems allowing
locking with angling, horizontal and vertical snapping, side push
etc. could be used. The floor panels could however also have rather
simple locking systems or only straight edges similar to tiles and
stone and they could be glue down to the sub floor.
[0175] FIG. 8a shows a panel according to an embodiment of the
disclosure that could be produced with the same basic equipment
that is generally used in conventional laminate floor production.
The panel comprises a surface layer 5, a HDF core 6 and a balancing
layer 7. The surface layer is preferably in a powder form such that
it could be scattered as a thin layer and formed to for example a
0.1-0.5 surface layer on a pre-fabricated fibre based core,
preferably a 6-8 mm HDF core. The binder could be adapted such that
pressing could be made in conventional continuous or discontinuous
direct lamination presses with pressing times, temperature and
pressure similar to the parameters used today. The thickness of the
surface layer could vary but it is preferred that the final
thickness of the surface layer exceeds the depth of the embossing
or at least that these parameters are essentially in the same
range. Recycled HDF fibres from the cutting and machining of the
edges could be used in the surface layer.
[0176] FIG. 8b shows floor panels 1, 1' with a mechanical locking
system comprising a strip 46 with a locking element 48 that
cooperates with a locking grove 44 and locks the panels 1, 1'
horizontally. The locking system comprises also a tongue 40 that
cooperates with a tongue grove 49 and locks the panels 1, 1'
vertically. A flexible sealing material 50 could be applied during
production or during installation between two edges in order to
create a decorative effect and/or to prevent moisture to penetrate
into the joint. A thermoplastic material could be incorporated into
the fibres during production and could be machined to an edge
sealing that is integrated into one or both adjacent edges.
[0177] The forming of the edges could be made in the conventional
way with large rotating diamond tools. The upper edges, which in
some embodiments could be extremely wear resistant, could be formed
with high quality diamond tools that break and separate the wear
resistant particles from the wood fibre matrix. As an alternative
laser or carving with diamond tools could be used. A preferable
embodiment is a combination of laser and carving where straight
cuts and preferable the top edges are formed with laser while
U-formed grooves, cavities and rounded parts preferably in the
softer core material under the surface layer are formed with
carving. A laser beam could also be used to seal the edges,
preferably the upper part of the edges, with heat.
[0178] Laser cutting is especially suitable to form edges or
grooves with a rough structure that looks similar to a rough stone
or tile edge. Such rough edges could be formed with a laser cutting
head having a beam with a focus position and/or focus distance
and/or beam geometry that varies along an edge when for example a
part of a panel edge is displaced in relation to the laser cutting
head. Such edges are not possible to form with conventional cutting
tools. All these methods and embodiments could also be used in
traditional laminate and wood floorings.
[0179] FIG. 8c shows floor panels with a combination core that for
example could comprise of a surface layer 5, a core layer 6a
comprising for example cork particles bonded together according to
an embodiment of the disclosure, a wood fibre based core comprising
wood fibres and a balancing layer that for example comprises cork
particles. All layers could have different densities.
[0180] FIG. 8d show that an essentially horizontally extending
groove 52 could be formed with for example carving, conventional
machining or laser cutting, in the core under the surface layer. An
essentially vertical cut 51 could be formed in the surface layer in
the same way and an upper surface could be removed with limited
machining and tool wear. Rough bevels could be formed in an edge in
similar ways.
[0181] FIG. 9a,b show a scattering station 60 which could be used
to distribute dry materials in layers. Fibres, wear resistant
particles, binders in powder form and colour pigments in powder
form could for example be mixed and applied into a container 55
that is in contact with an engraved roller 53. This roller 53
brings during rotation the mixed material 56 into contact with a
brush roller 54 and the material 56 is applied on a conveyor belt
20 or on another layer or board material
[0182] The direction of the material flow could effect the position
of the particles as can be seen from FIG. 9a where larger and
heavier material are applied under lighter particles and FIG. 9b
where the opposite takes place. This separation of particles in
different layers is obtained by the brush roller 54 that causes the
heavier particles to be distributed further away than lighter
particles that falls more vertically towards the conveyor belt
20.
[0183] Hard wear resistant particles create high abrasion on steel
plates during production. This problem could be avoided if one of
several of the below mention methods are used.
[0184] The upper layer could comprise melamine powder and essential
flat aluminium oxide particles.
[0185] A very thin upper layer, for example only fibres and
binders, which does not comprise aluminium oxide particles, could
be applied over a wear resistant layer. This thin layer will
disappear shortly after installation. The decorative effects will
however be maintained due to the solid structure of the surface
layer.
[0186] The upper part of the surface layer could comprise a thin
layer, which comprises of for example essentially only
melamine.
[0187] Wear resistant particles in the upper part of the surface
layer could be extremely small and have a nano particle size.
[0188] Thin wood veneers could be combined with a fibre layer in
order to produce a surface layer that has a similar appearance as
thicker and more solid wood surface layers. A wood veneer could
also be formed and connect to a wood fibre based core in the same
production step that is used to form the core. This method could
reduce costs and eliminate production steps according to the
overall objective of an embodiment of the disclosure.
[0189] FIGS. 10a-c show how a thin surface layer 5, preferably a
wood veneer layer with a thickness of for example 0.3-1.0 mm, could
be formed with deep structures that give an appearance similar to
solid wood. FIG. 10a shows how a floorboard could be produced. A
thin surface layer 5 is applied on a sub layer 6b comprising for
example cork 6a or wood fibres mixed with a binder, preferably a
thermosetting binder. The sub layer 6b is applied on for example a
wood fibre based core, preferably a HDF core. Other core materials
could be used such as particleboard, plywood, plastic materials,
non-woven impregnated materials of natural fibres etc. A balancing
layer 7 could also be applied to the core 6. FIG. 10b show how the
core and the layers are pressed together with an embossed pressure
matrix 23. This pressing forms the sub layer 6b and the surface
layer 5, which are cured and connected to each other under heat and
pressure. Very deep embossing could be obtained and a rough surface
similar to hand scraped solid wood could be created with a thin
wood veneer. The sub layer could be used to improve the properties
of the surface layer, for example sound absorption and impact
resistance. This method could also be used to apply a wood veneer
directly on a core according to the IFP principle or it could also
be used in a traditional HDF production line. HDF is formed and the
wood veneer is laminated to the core in the same production step.
This method gives cost savings, since sanding of HDF and gluing of
the veneer could be avoided.
[0190] All of the above described embodiments could be used
individually or in combinations.
[0191] A floor panel with a very wear resistant surface layer
according to an embodiment the disclosure could be difficult to cut
with an ordinary saw. It is preferred that the floor panel is cut
from the rear side where a groove 39 could be made up to the lower
part of the surface layer 5 as shown in FIG. 6f. The floor panel
can then be bended and split or broken apart.
[0192] Individual floor elements 2 or floor panels 1 could also be
produced and parts of the locking system could for example be
formed in the pressing operation. Tile and stone shaped products
could also be produced as individual products without any locking
systems and they could be formed at the rear side with pre-glued
layers such that they could be easier to install in the traditional
way by attaching them to the sub floor. Mechanical locking system
could also be used to facilitate glue down installation in the
conventional way. A rear side could be produced with a rough
structure or a specially adapted structure, which facilitates the
gluing.
[0193] In order to simplify production and decrease tool wear,
special softer fibres or material without wear resistant particles
could be applied locally in the surface where separation of the
floor board into floor panels will be made and where part if the
locking system will be formed. Pre formed grooves on the rear side
could also facilitate separation.
[0194] FIG. 11a shows a panel with two separate surface layers 5,
5' with preferably different design or structure. Decorative
grooves 8 could be formed to a depth such that the lower surface
layer 5' is visible, as shown in FIG. 11b. Very accurate and
attractive design effects could be obtained.
[0195] Scattering through a pattern form or schablon 27 as shown in
FIG. 11c could be used to create decorative effects. Fibres 14 of
different colour and structure, preferably mixed with binders 19
and/or colour pigments 15 and/or wear resistant particles 12, could
be applied on well-defined surface portions.
[0196] Fibres of different colour or structures could also be used
to form decorative portions on the surface in varies ways for
example by separate extruders that apply fibres in well-defined
surface portions separated by thin walls which are removed before
pressing or that consist of materials that could be included in the
surface, preferably in a production with the panel surface pointing
downwards during the pressing.
[0197] FIGS. 12a-e show in several steps how a panel according to a
preferred SOC principle is formed in a discontinuous pressing
operation and problems related to such production. A pre-fabricated
core 6 of for example HDF is placed on a pre-fabricated balancing
layer 7 as shown in FIG. 12a,b. A surface layer 5 comprising wood
fibres, binders and color pigments, preferably in dry form, is
placed on the core with a scattering or dust spreading equipment as
shown in FIG. 12c. The core with the surface layer and the
balancing layer is pressed in a discontinuous press as shown in
FIG. 12d and formed to a floorboard as shown in FIG. 12e. FIGS. 12c
and 12d show that the soft surface layer 5 comprises prior to final
pressing a lot of air 45 that must be evacuated when the upper 37
and lower 37' press tables are closed. This could create an air
flow 45 that displaces the soft surface material in an uncontrolled
way. This problem could be solved in different ways for example by
a pre pressing of the surface layer prior to the final pressing or
by applying vacuum that extracts the excess air. Vacuum could be
applied on the rear side of the core and used in combination with
for example a matrix or release paper on the surface. A HDF core
has sufficient porosity to allow vacuum, applied on the rear side,
to affect the surface on the front side. Liquid resins or water
sprayed over the fibres could also be used to stabilize the surface
layer.
[0198] FIGS. 13a-k show embodiments of double-sided floor panels
with surface layers 5, 5' on both sides and with locking systems
which allow installations of such panels with vertical (FIG. 13a,
13d) snapping, angling (FIG. 13g,h) and horizontal snapping (FIG.
13i). The locking systems has in the shown embodiments separate
flexible tongues 9 or locking elements 9a which facilitate an easy
snapping with low snapping resistance. Similar one piece locking
systems could also be used. Known locking systems have been
adjusted such that both the front sides and the rear sides of
adjacent panels have edge surface portions 38, 38' that could be
locked to each other with preferably a tight fit. It is an
advantage if both sides of the floor panel could be used, provided
that the extra cost for the second surface layer is limited as
could be the case with a floor panel according to the
disclosure.
[0199] FIGS. 14a-14e shows a method which could be used to produce
floor panels with very advanced surface designs even in a case
where the basic original floor board has a rather simple surface
design. This "combi panel" method is particularly suitable for
composite floorings according to embodiments of the disclosure but
it could also be used in other floor panels with preferably a
surface design based on printing, coloring, or other artificial
designs which are used in for example laminate floorings, linoleum
and resilient floorings.
[0200] The method comprises production steps where a first 3 and
second 3' original floorboard with different designs or structures,
FIG. 14a, are cut into first type of floor elements 2, 2', FIG.
14b. The first type of floor elements is connected to a combi
floorboard 3a that comprise at least one floor element of the first
and second original floorboards, FIG. 14c. The combi floorboard 3a
is cut to a second type of combi floor elements 2a which comprises
surface portions of the first and second original floorboards (FIG.
14d) and formed to a combi floor panel 1, FIG. 14e, with preferably
mechanical locking systems at the edges. The first type of floor
elements 2, 2' is preferably connected to each other with a
mechanical locking system in order to form a combi floorboard 3a. A
conventional tongue and groove could also be used. The method
offers the advantages that a wide range of very advanced combi
floor panels 1 could be produced from a limited range of rather
simple original floorboards 3, 3'. The need for various types of
press plates will be reduced. A broad range of for example laminate
floorings could be produced with a limited range of decorative
papers.
[0201] FIGS. 15a-15d show that the combi panel method could be used
to produce extremely advanced decorative effects in a cost
effective way. A combi floorboard 3a of a first type could be
produced as described above and could be connected with a combi
floorboard of a second type 3a', produced in the same way but with
a different floor element combination or design. The combi
floorboards 3a, 3a' of the first and second type could be connected
to a new combi floorboard 3b as shown in FIG. 15b and cut into new
combi floor elements 2b as shown in FIG. 15c. Such new combi floor
element 2b could have surface portions from two or three or four or
more original floorboards. The combination effects are almost
unlimited even in the case when a few original floorboards are used
to form combi floor elements with different sizes that are combined
into combi floorboards. Floor elements with decorative grooves
could increase the decorative effects. Turning of the original
embossing direction will increase the decorative combinations
further. Even a combination of for example black and white original
floorboard makes it possible to create advanced decorative effects
if combi floor elements of different sizes and preferably with
decorative grooves are used.
[0202] The long edges of the combi floor elements, as shown in FIG.
14c could be formed and connected with locking systems 4a,4b that
could be used as locking systems on the short edges in the combi
floor panel 1 as shown in FIG. 14f. This will decrease the
production cost since no final machining of the short edges will be
needed in order to form a locking system and all combi floor
elements could be of the same size. Special locking systems could
also be made that could be used to form more advanced locking
systems on the short edges in a final machining process, for
example a locking system with a flexible tongue allowing vertical
locking. The final machining could be very simple and limited to
simple horizontal or vertical grooves.
[0203] FIGS. 16a-e show a preferable method to create a surface
layer with an in register embossed surface (EIR), especially in a
composite flooring according to embodiments of this disclosure. An
embossed pressure matrix 23 is provided preferably as a sheet,
structured paper, a roller and similar with a surface that
comprises embossed protrusions 29 as shown in FIG. 16a. A
decorative material for example paint or colored fibres or similar
is applied on the protrusions 29 with an application device for
example a rubber roller 28 or similar. A surface layer 5 comprising
uncured fibres and binders is provided as shown in FIG. 16c and the
pressure matrix 23 is pressed against the surface layer 5, as shown
in FIG. 16d. The decorative material 29 will be positioned at the
lowest surface portions and a perfect in register embossing will be
obtained as shown in FIG. 16e.
[0204] This method is very suitable for all types of surfaces where
decorative parts could be included in the surface during the final
forming and curing of the surface in a pressing operation. Paint
could be used that during pressing penetrates into the basic fibre
structure.
[0205] The description below and the FIGS. 17a-17f are intended to
show explanatory embodiments of some process variations that have
been explored within the scope of this disclosure.
[0206] The first example is related to an integrally formed panel
(IFP) with a total thickness of 8-10 mm, a surface layer of about 1
mm and a balancing layer of about 1 mm.
Example 1
[0207] In the present case the resulting product has a decorative
surface texture achieved through an embossed paper.
[0208] The following raw materials are used: [0209] Melamine resin
in powder form [0210] Aluminium oxide in powder form 70-110 microns
[0211] Colour pigment [0212] Wood fibres of HDF/MDF panels,
mechanically separated, comprising natural resins
[0213] Process Operations:
[0214] Drying & Moisture Control
[0215] The wood fibers are dried to a moisture content suited for
the process, for example 5-8%.
[0216] Sieving
[0217] A sieving operation is used to separate and classify the
fibers into fibers suited for further processing and to fibers that
need to be mechanically milled in order to reduce the size
further.
[0218] Milling
[0219] The fiber fractions with large fibers are milled to a useful
size and recirculated to the sieving operation.
[0220] Mixing
[0221] Raw materials are mixed to compositions suitable for the
different layers, such as the surface layer, the core, and the
balancing layer, using mechanical dry mixing technology ensuring a
homogenous mixture. The different compositions are stored in
separate containers.
[0222] Surface Layer Composition
[0223] The surface layer of the IFP product is based on a mixture
of Melamine resin (e.g., Kauramine 773, BASF, Germany), Aluminum
Oxide (e.g., ZWSK180, Treibacher, Austria), colour pigments for
example a black pigment (e.g., Bone Black, Alfort & Cronholm,
Sweden) and wood fiber (e.g., production waste from laminate floor
profiling) sieved to a fiber size smaller than 150 .mu.m.
[0224] In this explanatory embodiment the following proportions
were used:
TABLE-US-00001 Surface layer composition Material Amount (g/m2)
Wood fiber 670 Melamine resin 670 Pigment 80 Aluminium oxide
670
[0225] Core Layer
[0226] The core layer of the panel is based on a mixture of
Melamine resin (e.g., Kauramine 773, BASF, Germany) and wood fiber
(e.g., production waste from laminate floor profiling) milled to a
fiber size in the range of 150 to 600 .mu.m.
[0227] The composition was used in the following proportions:
TABLE-US-00002 Core layer composition Material Amount (g/m2) Wood
fiber 6700 Melamine resin-773 670
[0228] Balancing Layer
[0229] The balancing layer of the panel is based on a mixture of
Melamine resin (e.g., Kauramine 773, BASF, Germany), Yellow pigment
(e.g., Yellow Ochre, Alfort & Cronholm, Sweden) and wood fiber
(e.g., production waste from laminate floor profiling) sieved to a
fiber size smaller than 150 .mu.m.
[0230] The composition was used in the following proportions:
TABLE-US-00003 Balancing layer composition Material Amount (g/m2)
Wood fiber 670 Melamine resin-773 670 Pigment 80
[0231] Scattering the Top Layer
[0232] The panel is produced with the decorative surface layer
downwards. Hence, the initial step of scattering is to position a
surface texture material such as embossing paper 23 (e.g., Sappi,
US) on a thin aluminum plate as shown in FIG. 17a.
[0233] The top layer material 5 is then scattered on the embossing
paper 23 using the scattering equipment shown in FIG. 9a. This is
shown in FIG. 17b.
[0234] The core layer material 6 is scattered on the top layer 5 as
shown in FIG. 17c.
[0235] Scattering Backing Layer
[0236] The balancing layer 7 is scattered on the core layer 6 as
shown in FIG. 17d and covered with a release paper.
[0237] Loading
[0238] The aluminum plate carrying the scattered layers is loaded
into a press.
[0239] Pressing
[0240] The scattered layers are pressed with an upper 37 and lower
37' press table in the press, as shown in FIG. 17e, with a pressure
of 40 kg/cm2. The press is heated from both sides to 160.degree. C.
and held for two minutes. The laminated material is cooled to
40.degree. C. prior to opening the press.
[0241] Unloading
[0242] When the press is opened the laminated panel is lifted out
of the press and the embossing paper and the release film are
removed. The resulting product, that in this embodiment is a floor
board 3, is shown in FIG. 17f. The floor board is shown with the
decorative surface layer 5 upwards.
[0243] Sawing, Profiling & Packaging
[0244] The floor board is cut to floor elements and machined to
floor panels with mechanical locking systems at the edges. The
finished product could preferably be conditioned to a suitable
climate prior to packaging and shipping.
Example 2
[0245] The process description below is related to a surface on
core panel (SOC) where a surface layer is produced on a separate
pre-fabricated core. The panel has in this preferred embodiment a
decorative surface layer of about 0.4 mm and the total thickness is
about 8 mm.
[0246] The following raw materials are used: [0247] Melamine resin
in powder form [0248] Aluminium oxide [0249] Pigments [0250] Wood
fibers [0251] High Density Fiber Board (DHF) as a core [0252]
Backing paper as balancing layer
[0253] Process Operations:
[0254] Drying and moisture control, sieving, milling and mixing
operations are substantially the same as for the IFP panel
described above.
[0255] Surface Layer
[0256] The surface layer of the product is based on a mixture of
Melamine resin (e.g., Kauramine 773, BASF, Germany), Aluminum Oxide
(e.g., ZWSK180, Treibacher, Austria), Black pigment (e.g., Bone
Black, Alfort & Cronholm, Sweden) and wood fiber (e.g.,
production waste from laminate floor profiling) sieved to a fiber
size smaller than 150 .mu.m.
[0257] The composition for the surface layer was as follows:
TABLE-US-00004 Surface layer composition Material Amount (g/m2)
Wood fiber 130 Melamine resin-773 130 Pigment 130 Aluminium oxide
130
[0258] Scattering on a Core
[0259] The product is produced having the decorative surface layer
upwards. Hence, the initial step of scattering is to position a
core material (7.8 mm Varioboard (High Density Fiberboard (HDF)),
Wiwood, Sweden) under the scattering device shown in FIG. 9a.
[0260] The surface layer material is then scattered on the HDF.
[0261] Loading
[0262] The HDF carrying the scattered surface layer is positioned
on top of a backing paper (e.g., Melamine resin impregnated 200
g/m2 paper, DKB, Germany) that is carried by a release foil. Also
the scattered layer is covered by a release foil. The materials are
loaded into a press.
[0263] Pressing
[0264] The press is closed to a pressure of 40 kg/cm2. The press is
pre heated from both sides to about 180.degree. C. and held for
twenty (20) seconds.
[0265] Unloading
[0266] When the press is opened in hot condition the laminated
product is lifted out of the press and the release films are
removed. The product is left to cool to ambient temperature.
[0267] Sawing, profiling, packaging etc. is made in the same way as
for the IFP panel.
[0268] The described SOC production method makes it possible to
create a surface layer in a floor panel which is about four times
more wear resistant than a conventional laminate flooring. Impact
resistance is also better. The pressing time is substantially the
same which means that the pressing capacity and cost is
substantially the same for both products. The raw material cost for
the surface layer in a SOC panel is however lower even in
embodiments where the surface layer comprises more aluminium oxide
and colour pigment than in a traditional laminate floor panel. The
main cost advantage is the fact that no surface papers has to be
produced, printed and impregnated.
[0269] The fibres in the surface layer are as described above
preferably recycled fibres from the cutting and machining of the
edges. The fibre content in the surface of the SOC panel in the
described example above is about 5% of the total fibre content and
this is substantially the same amount as the amount of fibres that
will be obtained from the edge machining. This means that the fibre
cost could be almost zero. Conventional laminate flooring
production gives a considerable amount of excess fibres and such
fibres could be used in the surface, core and balancing layer of a
floor panel according to the disclosure.
[0270] A particle board core that is generally less costly than
HDF, could be used to reduce the production cost further.
[0271] The present invention is not limited to the described
embodiments and Figures.
[0272] The binders could for example comprise formaldehyde free
binders which are regarded as more environmental friendly than
traditional binders used in laminate floorings. A preferable
formaldehyde free synthetic binder is a liquid or dry thermosetting
binder such as for example carboxy or hydroxy functional polyester
with suitable cross-linking agent. Examples of such is the
combination of the carboxy functional polyester Uralac P880 (DSM,
NE) and the curing agent Primid XL-552. Another synthetic
thermosetting binder that can be used is functionalized
polyacrylates. Suitable fictionalization is for example carboxylic
that can be paired with epoxy and/or hydroxy functionalities. An
example of the combination of hydroxy and carboxy fictionalization
is found in for example Acrodur 950L made by BASF (DE). The binder
ratio, pressing time and pressure are substantially the same as for
a melamine formaldehyde resin. Other formaldehyde free
thermosetting binders which could be used are based on urethane
chemistry such as with the combination of polyol compounds based on
polyester, polycarbonate, polycaprolactone or polyacylate chemistry
with isocyanate functional compounds including basic isocyanates
such as di-phenylmethane diisocyante (MDI). The use of crude MDI
(pMDI) can also be used without further addition of compounds
including isocyanate reactive groups.
[0273] It is also possible to obtain an environmentally friendly
"green" product by using natural resins as a binder for example
lignin, suberin, modified starch or modified proteins or other
similar natural resins.
[0274] Chemical foaming agents such as sodium bicarbonate, together
with a binder, could for example be used in order to decrease the
density and/or to increase the thickness after pressing to make
decorative effects. Other similar exothermic or endothermic
chemical blowing agents are azoisobutyronitrile (AIBN) and
azodicarbonamide (ADC). Gas or liquids could also be used to
facilitate foaming as for example possible through the addition of
liquid filled plastic microspheres such as Expancel.RTM..
[0275] Lower density could also be achieved by the introduction of
low density fillers such as silica aerogels, for example
Cabosil.
[0276] The pressing operation which preferably is a dry process
could alternatively be replaced by a liquid process where a powder
slurry or a paste comprising wood fibres, binders, preferably
synthetic thermosetting binders and wear resistant particles,
preferably aluminum oxide, could be used for continuous or
discontinuous mold filling with low or high pressure such that a
floor panel with for example beveled edges and preferably a locking
system could be formed. Such a production method is more
complicated and more costly than the embodiments described above,
but could be used in special applications such as for example wear
resistant base moldings.
[0277] Printing using the "stamp" method could be replaced with a
"vibration" method. If the panel for example is produced with its
front side downwards against a matrix, a vibration step could be
added after the first surface layer is scattered on the matrix. The
vibration could be used to position the scattered
material--comprising for example particles of a certain colour or
scratch resistance--into the deepest spots of the matrix. This
means that those deepest parts on the matrix will be on the highest
surface points of the final panel. A "perfect" coordination between
a design and an embossing, generally referred to embossing in
register (EIR), could be achieved. Additional decorative layers may
be applied on the matrix such that they comprise upper parts on the
matrix and lower parts on the panel surface.
[0278] Digital or direct printing could for example be used to
apply a print indirectly on the panel surface for example prior or
during the curing of the surface. A "transfer" print could be
provided on a carrier such as an aluminium foil or a press plate or
a structured paper. The print could be transferred from the carrier
to the panel surface prior to pressing or during pressing. The
printing device could for example be placed on the upper side in a
continuous press and the print could be in register with the
embossing of the steel belt. Such transfer printing, may also be
accomplished by first applying a colour on the structured foil with
e.g., a roller, removing the colour with a scraper from the outer
parts of the structured foil and then adding a new colour with
e.g., a rubber roller on these outer parts.
[0279] If an original product, for example stone, is copied both in
relation to colour and embossing a "perfect" reproduction could be
obtained with the above methods. Density and wear resistance could
be adapted such that the reproduced panel feels and performs like a
real stone.
[0280] Colour pigments and other decorative or non-decorative
materials could be included in the surface and could give different
design effects when subjected to different heat and/or pressure.
This means that decorative effects could also be obtained by using
varying heat on the press plate surface to create different decor
colors with the same base materials. The structure of the pressing
matrix could be used to create different pressures and this could
also give different designs in the low and high spots on the
surface. An increased pressure could be obtained locally by
applying more material on some surface portions than on other
adjacent portions. Increased density in specific portions that
preferably constitutes edge portions in the final floor panel,
could also be made in a similar way. This could be used to form a
strong locking system and to improve moisture resistance. This
means that the density profile could very along a horizontal plane
in the surface or in the core. An increased amount of wear
resistant particles and/or binders could be applied on the
protruding surface portions in order to increase wear resistance,
impact resistance or to create decorative effects. This embodiment
of the disclosure is characterized in that the panel comprises a
surface with protruding portions and lower parts wherein the
protruding surface portions comprise different material
compositions than the lower parts.
[0281] A printed foil could be used that melts into the top layer
during the pressing operation. Such foil could be combined with
additional wear resistant particles or design particles, chemicals
for water resistance impregnation or special chemicals to create a
glossy surface.
[0282] Decorative particles such as colour flakes or fibres could
be used to produce stone replicas with a 3D "printing" effect.
Thermo plastic particles with colour pigments that completely or
partly will melt during the pressing operation could also be used
in the surface layer and different viscosity of the particles in
heated condition could be used to control the decorative effects
created by the decorative particles.
[0283] Special problems could occur when a core of for example HDF
is placed on a scattered fibre layer that comprises a backing layer
or a surface layer. The air flow of the core, when it is lowered
downwards towards the fibre layer, will blow away fibres,
especially if the aim is to shorten the pressing cycle as much as
possible. The same problem occurs if the press table is closed
against an upper uncured fibre layer. Such problems could be solved
by applying liquids on the fibres, for example liquid binders or
similar. Another solution is to use a special vacuum equipment to
place the board material on the scattered fibre structure in order
to evacuate excess air. A vacuum gripper could be used with the
same properties as a vacuum table often used when thin board
materials has to be machined. Perforated backing material could
also be used in order to stabilize the balancing layer, the core
and the surface layer during the infeed into a press. Vacuum could
be used to completely or partly replace pre-pressing prior to final
pressing.
[0284] To improve wear resistance, the structure paper/foil could
be coated with liquid melamine mixed with Al.sub.2O.sub.3 and
dried. A print could be applied to this dried surface and
transferred to an upper preferably wear resistant fibre surface,
when the panel is cured in the press. Several advantages could be
obtained: [0285] a) grooves in the upper decorative part, extending
to a lower part with different design, could be made in order to
create decorative groove portions. [0286] b) a design could be
created that could be varied during the lifetime of the product
when parts of the surface is worn down, similar to wear of a
natural stone. [0287] This method could also be used to increase
scratch resistance in conventional laminate floorings.
[0288] Random colour distribution can be achieved with airbrush
technique and be programmed and/or created with
"randomgenerator".
[0289] Double sided panels could also be produced with flexible
tongues or separate material that is applied on the edges during
installation such that all panels could be locked against any other
panel with any of the two sides as a surface side.
[0290] Using an overlay with wear resistant particles is not
excluded and this could increase the wear resistance.
[0291] The invention should not be considered as limited by the
above description; rather the scope and limitations of the
invention are defined by the enclosed claims, and equivalents
thereof.
EMBODIMENTS
[0292] 1. A building panel comprising a surface layer and a core,
[0293] the core comprising wood fibres, and [0294] the surface
layer comprising a substantially homogenous mix of wood fibres, a
binder and wear resistant particles, [0295] the substantially
homogenous mix of wood fibres comprising natural resins. [0296] 2.
The building panel as in embodiment 1, wherein the panel is a floor
panel comprising a balancing layer. [0297] 3. The building panel as
in embodiment 2, wherein the binder is a thermosetting or
thermoplastic resin. [0298] 4. The building panel as in embodiment
3 wherein the binder is a thermosetting resin. [0299] 5. The
building panel as in embodiment 4, wherein the wear resistant
particles comprise aluminium oxide. [0300] 6. The building panel as
in embodiment 5, wherein the core is HDF or particleboard, wherein
the surface layer further comprises colour pigments, and wherein
the wood fibres in the surface comprise fibres of the same material
type as in the core. [0301] 7. The building panel as in embodiment
4, wherein the binder comprises a melamine resin. [0302] 8. The
building panel as in embodiment 7, wherein the wear resistant
particles are bonded to the wood fibres with the melamine resin.
[0303] 9. The building panel as in embodiment 5, wherein the
surface layer comprises a vertical portion with three horizontal
planes extending parallel with the main plane of the panel wherein
a first upper plane located in an upper part of the surface layer
comprises a first aluminium oxide particle, a second intermediate
plane located under the first aluminium oxide particle comprising
wood and a third lower plane under the second plane comprising a
second aluminium oxide particle and wherein aluminium oxide
particles are in direct contact with an upper part of the core.
[0304] 10. The building panel as in embodiment 5, wherein the
weight content of the aluminium oxide particles in the surface
layer is in the range of about 5% to about 30% of the total weight
of the surface layer. [0305] 11. The building panel as in
embodiment 5, wherein the weight content of the aluminium oxide
particles in the surface layer is at least 100 gr/m2. [0306] 12.
The building panel as in embodiment 1, wherein the core is HDF.
[0307] 13. The building panel as in embodiment 1, wherein the core
is a particleboard. [0308] 14. The building panel as in embodiment
1, wherein the surface layer further comprises a print that extends
into the surface below upper wear resistant particles. [0309] 15.
The building panel as in embodiment 1, wherein the surface layer
comprises brushed portions with different fibre structures. [0310]
16. The building panel as in embodiment 1, wherein the surface
layer comprises brushed portions with different wear resistance.
[0311] 17. The building panel as in embodiment 1, wherein the
surface layer comprises wood fibres that are unrefined and comprise
lignin. [0312] 18. The building panel as in embodiment 1, wherein
the surface layer wood fibres are essentially smaller than 1 mm.
[0313] 19. The building panel as in embodiment 1, wherein the
surface layer wood fibres are in powder form and essentially
smaller than 0.5 mm. [0314] 20. The building panel as in embodiment
1, wherein a panel edge comprises a mechanical locking system for
locking of the panel with similar other panels and wherein such
locking system is formed in the core. [0315] 21. A building panel
comprising a surface layer connected to a core, [0316] the core
comprising wood fibres, [0317] wherein the surface layer, which
gives the panel decorative effect and wear resistance, is a
homogenous layer comprising parts of fibres, colour pigments,
binders and wear resistant particles. [0318] 22. The building panel
as in embodiment 21, wherein all parts of the surface layer are
present at an outer surface of the surface layer and at an inner
lower part which is connected to the core. [0319] 23. The building
panel as in embodiment 21, wherein the panel is a floor panel
comprising a balancing layer. [0320] 24. The building panel as in
embodiment 21, wherein the binder is a thermosetting or
thermoplastic resin. [0321] 25. The building panel as in embodiment
24 wherein the binder is a thermosetting resin. [0322] 26. The
building panel as in embodiment 21, wherein the wear resistant
particles comprise aluminium oxide. [0323] 27. The building panel
as in embodiment 24, wherein the binder comprises a melamine resin.
[0324] 28. The building panel as in embodiment 27, wherein the wear
resistant particles are bonded to the fibres with the melamine
resin. [0325] 29. The building panel as in embodiment 21, wherein
the surface layer comprises a vertical portion with three
horizontal planes extending parallel with the main plane of the
panel wherein a first upper plane located in an upper part of the
surface layer comprises a first aluminium oxide particle, a second
intermediate plane located under the first aluminium oxide particle
comprising wood and a third lower plane under the second plane
comprising a second aluminium oxide particle and wherein aluminium
oxide particles are in direct contact with an upper part of the
core. [0326] 30. The building panel as in embodiment 26, wherein
the weight content of the aluminium oxide particles in the surface
layer is in the range of about 5% to about 30% of the total weight
of the surface layer. [0327] 31. The building panel as in
embodiment 26, wherein the weight content of the aluminium oxide
particles in the surface layer is at least 100 gr/m2. [0328] 32.
The building panel as in embodiment 21, wherein the core is HDF.
[0329] 33. The building panel as in embodiment 21, wherein the core
is a particleboard. [0330] 34. The building panel as in embodiment
21, wherein the surface layer further comprises a print that
extends into the surface below upper wear resistant particles.
[0331] 35. The building panel as in embodiment 21, wherein the
surface layer comprises brushed portions with different fibre
structures. [0332] 36. The building panel as in embodiment 21,
wherein the surface layer comprises brushed portions with different
wear resistance. [0333] 37. The building panel as in embodiment 21,
wherein the surface layer comprises mineral fibres. [0334] 38. The
building panel as in embodiment 37, wherein the surface layer wood
fibres are essentially smaller than 1 mm. [0335] 39. The building
panel as in embodiment 34, wherein the surface layer wood fibres
are in powder form and essentially smaller than 0.5 mm. [0336] 40.
The building panel as in embodiment 21, wherein a panel edge
comprises a mechanical locking system for locking of the panel with
similar other panels and wherein such locking system is formed in
the core. [0337] 41. A method of manufacturing a building panel
comprising the steps of: [0338] mixing particles comprising fibres
or fibres with binders, colour pigments and small wear resistant
particles; and [0339] bringing the particles or the fibres, the
colour pigments, the binder and the small wear resistant particles
under high pressure and temperature and forming them to a building
panel. [0340] 42. The method as in embodiment 41, wherein the panel
is a floor panel. [0341] 43. The method as in embodiment 41,
wherein the fibres are wood fibres. [0342] 44. The method as in
embodiment 41, wherein the binder is a thermosetting or
thermoplastic resin. [0343] 45. The method as in embodiment 44,
wherein the binder is a thermosetting resin. [0344] 46. The method
as in embodiment 41, wherein the small hard particles comprise
aluminium oxide. [0345] 47. The method as in embodiment 41, wherein
the mixed particles are applied on a core comprising a wood fibre
based board. [0346] 48. The method as in embodiment 47, wherein the
wood fibre based board is HDF. [0347] 49. The method as in
embodiment 47, wherein the wood fibre based board is a
particleboard. [0348] 50. The method as in embodiment 41, wherein
the method comprises a pre pressing prior to the final pressing.
[0349] 51. The method as in embodiment 41, wherein the method
comprises a printing operation prior to the final pressing. [0350]
52. The method as in embodiment 41, wherein the method comprises a
machining operation wherein the building panel is formed to a floor
panel with mechanical locking systems at opposite edges. [0351] 53.
The method as in embodiment 41, wherein the method further
comprises the steps of: [0352] arranging the particles on a core
layer comprising wood fibres and a binder; [0353] arranging said
core layer on a balancing layer comprising wood fibres and a
binder; and [0354] applying heat and pressure to the three layers
comprising the particles, the core and the balancing layer. [0355]
54. The method as in embodiment 53, wherein the method comprises
applying a balancing layer that has a higher density than the core
layer. [0356] 55. The method as in embodiment 53, wherein the
binder is a thermosetting resin and the wear resistant particles
comprise aluminium oxide. [0357] 56. The method as in embodiment
41, wherein the wood fibres, the binder, colour pigments and wear
resistant particles are in dry form. [0358] 57. A building panel
comprising a surface layer and a core, wherein the surface layer is
a homogenous layer comprising cork particles, a binder and wear
resistant particles of aluminium oxide. [0359] 58. The building
panel as in embodiment 57, wherein the core comprises wood fibres
or cork particles. [0360] 59. The building panel as in embodiment
57, wherein the panel is a floor panel. [0361] 60. The building
panel as in embodiment 59, wherein the core comprises cork
particles and a binder of a thermosetting resin and wherein the
majority of the cork particles in the panel are smaller than 1.0
mm, and that the density of the panel exceeds 600 kg/m3. [0362] 61.
A method of manufacturing a floor panels with a decorative surface
layer comprising the steps of: [0363] providing a first and second
original floorboards with different designs or structures; [0364]
separating the original floorboards into a first type of floor
elements; [0365] connecting the first type of floor elements to a
combi floorboard that comprise at least one floor element of the
first and second original floorboards; [0366] separating the combi
floorboard into a second type of combi floor elements, which
comprises surface portions of the first and second original
floorboards; [0367] forming a mechanical locking systems on at
least two opposite edges of the second type of combi floor
elements. [0368] 62. The method as in embodiment 61, wherein the
surface layer comprises a homogenous layer of fibres, binders,
colour pigments and wear resistant particles. [0369] 63. The method
as in embodiment 61, wherein the floor panel is a laminate floor
panel.
* * * * *