"ARRANGEMENTS INTRODUCED IN PANEL INTENDED FOR FORMATION OF FLOORS".

The present utility model patent refers to constructive arrangements introduced in panel, which deals with core constituted of a sequence of wood veneer strips, fixed in oblique direction, vertically and in parallel to the length of the inner surface of a rectangular wood veneer, in order to constitute a panel susceptible of industrial application, and that will be used simultaneously as core and back face in the formation of wooden floors and of other materials. As it is of knowledge of technicians specialized in wood floor construction, there are currently floors with particleboard core — manufactured by using wood chips glued under pressure -, or with the core internationally known as H.D.F. [High Density Fiberboard] - manufactured with wood fibers and glued under high pressure -, or with flat plywood core made of wood veneer, or with core of solid lumber lath of approximately one inch of width. However, all these previously mentioned cores present problems resulting from warping and/or from swelling.

Under the most advanced technology, it is presented a core of laths of approximately one inch in width, with laths especially sawed, which obeys the perpendicularity of the growth rings of the slaughtered tree. This type of core is what has lower warping and/or swelling index, while its elaboration requires special cares in the follow-up of the growth rings, aspect that generated excessive wood waste, transforming the product of high quality but highly expensive. It is to be emphasized that this core presents a deficiency relative to the milling of the tongue in the one end of the panel, this is because the mentioned solid lumber laths are disposed horizontally and in parallel in the construction of this core, where it is

noted that after milling the elaborated tongue is treated with a jut of approximately 5 mm of length by approximately 5 mm of thickness, observing that in front of the longitudinal direction of the laths, the longitudinal wood grains become very fragile due to the stress to which they are submitted. In order to solve this deficiency, the manufacturer is obligated to place in the one end of the panel, instead of solid lumber laths, a strip of plywood of the same thickness and size as a lath. This plywood strip is disposed in the end of the last lumber lath, where it is noted that the plywood strip is formed by longitudinal and transversal sections, which gives sufficient resistance for the integrity of the tongue, however the plywood's density is never equal to the solid lumber's density. Obviously, the demand of such complementary constructive aspects contributes to raise even more the final cost of the product.

The arrangements introduced in panel intended for formation of floors, object of the present patent, were secretly idealized and conceived to minimize the problems resulting from warping and/or swelling, mentioned in the report of the state of the technique, for which, the proposed panel presents arrangements that involve inventive act and result in functional improvement in its use, where it is observed that in the sequence of strips of wood veneer in oblique direction, depending on the thickness of the panel to be constituted, are disposed approximately from three to eight wood fillets for the constitution of a strip of wood veneers, where the strips are fixed vertically and in parallel along the inner surface of a rectangular wood veneer, constituting a panel that will be used as core and back face in the formation of floors of wood and of other materials.

It is observed, therefore, that the elaborated core with especially sawed laths, obeying the perpendicularity of the growth rings of the

slaughtered tree, proven in the report of the state of the technique as the most advanced technology of the field, uses laths with more or less one inch of width, each one, presenting deficiencies after the manufacture of the floor itself, once the assembly is dried at more or less eight percent humidity, and in the sequence it is hermetically closed in a plastic packaging with the objective of not absorbing humidity in stocking and in transport. Still, after the removal of the plastic packaging, for the installation of the floor, and if approximately 48 hours have elapsed and the installation does not occur, depending on the temperature and humidity of the environment, the mentioned laths through their width - more or less one inch - absorb with sufficient ease the local humidity, hampering the installation or even making it unfeasible due to swelling of the tongue and groove, destined to fit each other.

Such previously described deficiencies are reduced to a minimum with the use of the panel object of the present patent, once the core is constituted by sequence of strips of wood veneers, where each strip is formed by the union of fillets of wood veneers with approximately 3 mm of thickness each fillet, which are glued to each other with waterproof phenolic glue, while the strips are fixed by gluing in oblique direction, vertically and in parallel along the inner surface of a rectangular wood back face veneer, where the assembly is dried at more or less eight percent humidity, and in the sequence, it is closed in a plastic packaging. Before such aspects, the panel object of this patent, upon being unpacked, permits the absorption of up to twice the initial humidity without harming the conventional fitting of the tongue and groove. It is to be stressed that in the panel object of the present patent, in case of an accident during the transport of the packed floors, with the impairment of the plastic packages,

even if the humidity penetrates, the swelling of the assembly will not occur, this is the situation that occurs with the elaborated core with laths of more or less one inch of width.

Fundamentally, the panel object of the present patent, provides the sufficient resistance for milling or elaboration of the tongue to be done, which has perfect structuring to support the stress to which it will be submitted, where the conventional use of the plywood strip will not be needed, and its density will remain uniform.

Finally, it is to be emphasized that the panel object of the present patent, presents structural and functional advantages and can be elaborated with less wood waste and at lower cost, with relation to the best one in the market, noticing particularly that existing interstices or symmetric crevices between the strips of wood veneer, are responsible for an effect of flexibility, where this does not exist in the tackled material in the report of the state of the technique .

The present patent can be better understood in the light of the enclosed drawings and their comments, for which it is obtained:

Figure 1., which shows in top view the core constituted by sequence of strips of wood veneers fixed in oblique direction, along the inner surface of a rectangular wood veneer.

Figure 2., which shows in top view the rectangular wood veneer of the panel intended for formation of floors.

Figure 3., which shows in side view the panel intended for formation of floors, evidencing the core constituted by sequence of strips of wood veneer fixed in oblique direction, along the inner surface of the rectangular wood veneer.

Figure 4., which shows in perspective the panel intended for the formation of floors, seeing in detail in circle that makes evident the interstice or symmetric crevice of separation between two strips of wood veneers. In accordance with what is illustrated in the figures, the arrangements introduced in panel intended for the formation of floors include core constituted by sequence of strips ( 1 ) of wood veneers, where each strip ( 1 ) is formed by the union of fillets ( 1-A ) of wood veneers with approximately 3 mm of thickness each fillet ( 1-A ), which are glued to each other with waterproof phenolic glue, while the strips ( 1 ) are fixed by gluing in oblique direction, vertically and in parallel along the inner surface of the a rectangular wood veneer ( 2 ) or back face, making evident between the strips ( 1 ) interstices or symmetric crevices ( 3 ) responsible for the effect of flexibility. The core constituted by the sequence of strips ( 1 ) of wood veneers, will receive afterwards a conventional top layer of noble wood or of other materials, which may have diverse thicknesses and sizes, occurring then the sanding and the milling of the tongue and groove at the four edges, thus forming the floor itself.