The present invention generally relates to the special construction and manufacturing process of engineered wooden- floorboard which could simultaneously perform surface durability, structural-integrity, stability and mechanical strength, compared to other existing wooden-floorboards either manufactured in solid or in engineered wood process.

Presently, the available options for floorboards are either in solid-wood flooring; engineered wood flooring, or High DensityFiberboard with a thin slice of wood (or plastic) lamination.

Solid-wood flooring is generally known for their more expensive cost; their heavier weights ; their lack of stability due to the nature of the solid-wood itself; and also their random, irregular length and width normally available, because of the method of their manufacturing.

Although they are structurally suitable for various different types of installation, quite often one or other disadvantageous factor described above might prove to be prohibitive.

Engineered-Wood Flooring is generally produced more for aesthetic installation, with limited engineered and structural merits. They are not produced with the intended surface-durability, structural-integrity, stability or mechanical strength, unless otherwise intended.

Laminate Flooring is mass-produced mostly for aesthetic and economical installation only, and works more like a floor-covering product than real wood flooring.

In European patent application EP 1 170 439, which has an earlier priority date than the priority date of the present application, but which was published after the priority date of the present application, a wooden floor board is described that comprises a top layer that is composed of a set of wooden strips, wherein elastomer membranes are placed between the strips to allow dimensional variations. The substrate of the wooden strips comprises a finger joint at one end and a groove on the other end side to allow the floor board to be connected to other floor boards that have similar finger joints and grooves. In French patent FR 1 070 192 a wooden floor board is disclosed wherein wooden strips of a top layer comprise finger joints for interconnecting the wooden strips.

The invention is created to answer requirements of engineered wood flooring with all the merits of durability, structural-integrity, stability and mechanical strength; but without the cost, weight, and disadvantages of solid-wood flooring; and with comparable aesthetics and beauty against any other pre-finished, engineered wood-floorings in market. Product dimension could also be made uniform for the ease of transportation, handling, storage and installation.

All the merits offered in the present invention are obtained by specifically having a particularly extreme thickness for the top layer (wear-layer) of the floorboard; by designing and inventing a unique method for the joints between the wooden-strips of the top layer assembly; and by choosing a specific bonding material and substrate material to be used in the product.

The object of the invention is to provide a wooden-floorboard having a surface-durability as the Solid Wood Flooring; having structural-integrity and mechanical strength as the Solid Wood Flooring; with a lighter weight and a more compatible cost.

The manufacturing, conditioning and assembling processes used the Engineered Wood Flooring process so as to make a high stability of the product as the Engineered Wood Flooring products.

The invention consits in the construction and manufacturing process of a wooden floorboard, as defined in claim 1.

• Figure 1 is a top view of finished wooden-floorboards of the invention.
• Figure 2 is a bottom view of finished wooden-floorboards of the invention
• Figure 3 is a detail of top-layer joint profiling, before being split, of the wooden-floorboards of the invention.
• Figure 4 is a detail of finished top-layer joint, when being split into 2 pieces, of the wooden-floorboards of the invention.
• Figure 5 is a side view of finished wooden-floorboards of the invention.

The present invention is created to diminish the drawbacks of many kinds of wooden-floorboards presently existed, by creating a unique product which could simultaneously perform high surface-durability; structural-integrity; and good mechanical strength; and also could perform high stability with competitive price with other wooden-floorboard products from the same class.

Unlike the solid wood flooring, the present invention can be manufactured with uniform sizes, and the finishing process is held in the manufactory itself, so as to completely provide the ease of packing, transportation, handling, storage and installation.

The present invention relates to a engineered wood flooring consisting of an assembly of top-layer (wear-layer) with an extreme thickness of between 5,0-9,0 mm (± 0,20-0,35") and a substrate of between 5,0-10 mm (± 0,20-0,40") custom rotary-cut plywood with special veneer composition and glue bonding.

As will be define below, a unique method has been found and designed for creating an assembly between wooden-strips of the invention.

In general, a conventional joining method is called butt-joint. In this method, we only need to solely joint the edges of the wooden-strips without any profiling, so that in this kind of joint, there will be no adequate strength since the area of glue-contact is as thick as the wood-strips themselves. When the surface of the wood-strips is worn-out and re-sandpaper, the joint becomes weaker as the surface of the wood-strips is dropped and the glue-contact area will be smaller.

A unique method for joining, invented and designed for the present invention, needs some mechanical processes for creating profiles, and the edges of the wood-strips to be joined, as a finger-joint profile and a high-scoring profile, are as can be seen from Fig. 3.

Finger-joint profile is designed for providing strong finger-joints between the wooden-strips when completed. This method is chosen in order to increase the surface of glue-contact area when compared to a conventional butt-joint, and on completion, it gives twice as much as area of glue-contact compared to conventional butt-joint.

After all profiles are ready, the assembly is done using a PVAc (Poly Vynil Acetat). This in turn creates very strong glue bonding and even stronger than the wood-strips themselves.

The high-scoring profile applied to the present joining method is intended to obtain and to maximize the thickness of the top layer (wear-layer) so as to achieve an extra-thick layer, which practically similar to the wear-layer thickness of solid wood flooring of comparable thickness.

The finger-joint profile made with around 10,0-12,0 mm (± 0,40"-0,47") high for creating a strong joint, meets a high scoring made to around 3,55-7,55 mm (± 0,14"-0,30") thick will provide not only an extreme thickness for the layer, but also a surface which is able to resist worn-out or re-sandpaper until the high-scoring is dropped; and even when it happens, the remaining joint area on the below finger-joint profile will still has a glue-contact area of more than 50% of the total width of the original joining area.

The wood-strips being finished to be joined and split into top layer (wear-layer) will be assembled together by using a substrate of custom plywood consisting of 4 until 6 rotary-cut veneers, laid up from top to bottom with alternating "short-long-short" pattern of grain direction, thus the lowermost veneer of the plywood, which will be the "back" of the finished floorboard, is long grain aligned with the grain direction of the top layer (wear-layer).

Veneers are bonded to each other using heat-cured Phenol Formaldehyde Resin glue. After hot pressed under high temperature. The resulted plywood has between ± 6,0-11,0 mm (± 0,24-0,44") thick before process and will get further finishing process.

The final assembly between the top layer (wear-layer) and the substrate plywood is done by cold pressing under high pressure, utilizing the similar PVAc (Poly Vynil Acetat) class B-4 exterior glue-bonding, like the top-layer assembly. After the final assembly, the edges of the floorboards are machined to create the tongue and groove profiles, as well as machined on the backside to create 6 pieces of narrow grooves across the width of the backside at an equidistant of 313,0 mm (± 12,32"), meant to balance the stresses within the floorboard assembly.

Finishing is done using the U.V. (ultra-violet) cured Acrylic lacquer in smooth, fine texture surface type.

There are several dimension of the finished floorboard of the present invention:

1. 1. L X W X H = 2,200 X 57 X 19 mm (± 86, 6 X 2,25 X 0,75")
2. 2. L X W X H = 2,200 X 60 X 19 mm (± 86, 6 X 2,36 X 0,75")
3. 3. L X W X H = 2,200 X 83 X 19 mm (± 86, 6 X 3,27 X 0,75")
4. 4. L X W X H = 2,200 X 90 X 19 mm (+ 86,6 X 3,54 X 0,75")
5. 5. L X W X H = 2,200 X 57 X 14 mm (± 86, 6 X 2,25 X 0,55")
6. 6. L X W X H = 2,200 X 60 X 14 mm (± 86, 6 X 2,36 X 0,55")
7. 7. L X W X H = 2,200 X 83 X 14 mm (± 86, 6 X 3,27 X 0,55")
8. 8. L X W X H = 2,200 X 90 X 14 mm (± 86, 6 X 3,54 X 0,55")
9. 9. L X W X H = 2,200 X 57 X 10 mm (± 86, 6 X 2,25 X 0,39")
10. 10.L X W X H = 2,200 X 60 X 10 mm (± 86,6 X 2,36 X 0,39")
11. 11.L X W X H = 2,200 X 83 X 10 mm (± 86, 6 X 3,27 X 0,39")
12. 12.L X W X H = 2,200 X 90 X 10 mm (± 86, 6 X 3,54 X 0,39") (L X W X H = Length X Width X Height of the product)

With all construction and manufacturing process of the wooden floorboard of the present invention, the need of a wooden floorboard with all advantages mentioned above will be achieved.

Various modifications, dimensions or even variations of the invention will be acceptable as long as they are within the scope of this invention as being claimed in the appended claims.