SK23395A3 - Light wood-wool building panel and method of its manufacturing - Google Patents

Abstract

The invention relates to a light wood-wool building panel with an open-pored structure of compressed wood-wool in which the wood-wool particles are incrusted at the surface with a binder, with the following features: the incrustation has a foam structure which extends at least partially into the pores of the light wood-wool building panel and is introduced during the panel shaping process by the infiltration of a foamed binder into a wood-wool random structure which is deformed while its volume is reduced at the same time.

Description

Technical field

BACKGROUND OF THE INVENTION The present invention relates to a lightweight wood wool board with a densified open-pored wood wool skeleton, wherein the wood wool particles are coated with a binder on their surface and to a method for producing the wood wool.

BACKGROUND OF THE INVENTION

Such lightweight wood wool panels have long been known under the trade name herakli t '.

It is an object of the present invention to provide a lightweight wood wool board of the above type which has a larger pore volume than the known heraclitic boards, i.e. wood wool particles will be less crowded, and preferably less binder will be required.

Problems to achieve this: wood particles are hindered by the following technical waves, which typically have a length greater than S cm, a width of 3 to 6 quite irregular geometry mm and a thickness of 0.2 to 05 mm, have and are brittle. These wood wool particles, which may also be referred to as wood wool particles.

therefore, they are fundamentally different from fibers that are much shorter and thinner and usually have a thickness of only a few micrometers.

While the fibers can be densified, for example, into mats or the like relatively easily, this densification of said wood wool chips is very difficult to perform.

The mixing of e ** wood wool particles with the binder also presents a particular problem. According to the prior art, wood wool chips are first coated with a binder suspension. The preformed chips are then processed into loose wood mass and then densified, whereby the densification is carried out at the points of contact adjacent to the pre-treatment of the chips until the bonding binder bridges are solidified. With this wood wool coating of the binder suspension, only relatively very densified boards can be produced in this way, the appearance of which is shown schematically in FIG. First

The basis of the solution according to the invention is surprisingly the finding that brittle wood wool chips of very low density can also be used for mass production of a stable wood wool building board as long as the binder joining these particles together is prepared as binder foam.

However, the use of a binder foam instead of a conventional binder sludge does not allow to solve the basic problem of the invention.

In addition, it has been found according to the invention that the unitary three sheets of free wood mass can be coated entirely on their surface and can be joined together in free configuration if the binder foam is introduced into the free wood mass during densification.

The basis for this is to have a density only in the range from A to the following: wood free mass up to 10 kg / m ³ . In other words, more than 90% contains air. The bonding of the wood wool chips with a binder foam mixer with forced mixing is excluded.

The connective foam would be destroyed (DE 25

912 A1) and wood wool chips would break.

The impregnation of wood wool particles with a binder foam (such as DE 20 04 246 C3) could be carried out in a relatively dense fiber mat.

but not a very low density loose wood mass.

Also, impregnation of the pre-fabricated fiber mat described in DE 20 04 246 C3 cannot be transferred to lightweight wood wool building boards of the kind described above, and impregnation after pre-densification would no longer allow the entire surface of the individual wood wool chips to be completely coated. connection points between individual chips.

On the basis of similar considerations, the solution according to DE 1 117 467 B1 can also not be transferred to lightweight wood wool boards. In the solution according to this patent, a cementitious mortar and fiber mass is first produced, which is subsequently foamed by a suitable means. In the processing of wood wool chips, the mass thus prepared cannot be used for the above reasons.

A completely different approach is therefore described in German patent specification 899 470. In this document, it is recommended that the magnesium cement treated in the form of a foam be poured into molds and allowed to cure, whereby individual particles of wood wool can be incorporated into the foam.

Obviously, molded parts manufactured in this way cannot be produced continuously. In addition, foamed magnesium cement articles are extremely fragile, even when individual wood wool chips or other additives have been introduced into the foam. Mass production technical products such as lightweight building boards made of wood wool cannot be produced in this way.

According to DE-AS 1 025 778, lubricants and other materials are also produced by mixing the binder foam with a plnidoma (e.g. wood flour). Addition of the artificial resin and / or resin to the foam will stabilize it.

SUMMARY OF THE INVENTION Mentioned above shortcomings eliminates easy board made of wood wool with skeleton of densified woody waves with open pores. where the wood wool particles are on

the surface of which is provided with a binder coating according to the invention, which is characterized in that the coating has a foam structure which extends at least partially into the pores of the lightweight woodboard and during infiltration of the lightweight woodboard has been introduced into the molded loose wood while reducing the volume.

With a lightweight wood wool board may be from stabilizing the connective foam. as well as any mixing, abandoned.

The binder foam is thus pushed into the loose wood mass, i.e. when the loose wood mass is compacted to the desired final dimension. In this way, the binder foam may first penetrate into the relatively loose wood mass, wrap the surface of the individual chips there and during the further densification of the loose wood mass optimally dispose therein. In this case, the binder foam is subjected to minimal mechanical stress, so that the foam structure remains almost completely preserved. The densification of the loose wood mass is carried out continuously and flat, so that the individual chips can be re-orientated individually in this densification, whereby the still solidified foam coating acts as a resilient surface coating.

In FIG. 2 shows a typical structure of a lightweight wood wool board according to the invention. Compared to the prior art embodiment shown in FIG. 1, a very loose structure and thus a very large pore volume (corresponding to a distinctly lower density) can be seen.

However, the strength of the lightweight board is surprisingly high. At the same time, this board has excellent soundproofing properties.

The loose structure means optimal use of this lightweight board for insulation and damping purposes.

The interior of the pores in the skeleton formed between the densified wood wool particles may be more or less completely filled with hardened binder foam. The degree of filling is selected according to the desired properties and use of the finished product. The degree of filling can be influenced, for example, by a suitable additive which is admixed in the binder and which changes the curing time of the foam or its porous structure. These additives (retarders, accelerators, pore formers) are known in the art and will therefore not be described in detail.

The same applies to the binder itself, which can be made of hydraulic cement as well as of Sorel cement. Foam-forming agents such as soaps, surfactants, sulfonates (e.g. lignosulfonates), but also metals or metal combinations in the form of powders, such as aluminum / zinc or magnesium, as well as hydrogen peroxide, are prior art and will not be described in detail .

They are selected according to an exemplary embodiment such that the cured binder foam has a density of from 100 to 700 g / l and / or pores with a mean diameter of from 0.2 to 5 mm.

A typical wood wool ratio of binder foam ranges from 16 to 2: 1.

Depending on the field of application, a binder foam may be used, the foamed body of which will disintegrate over time. The stability of the lightweight wood wool board is then primarily dependent on the bond contact points of the chips between each other.

However, it is also possible to provide a foam matrix which is designed in a targeted manner, even in individual parts of the light board. It is therefore easily possible, above all, to provide a thin foam layer on the surface of the board, so that - purely optically - the board has a continuous ** surface, which can then be coated with a paint or other coating.

The lightweight wood wool board described above can be produced continuously and continuously. In each case, a binder foam is applied to at least one planar portion of the free wood mass, which then infiltrates into the free wood mass as the volume decreases. In this process, a stable volume of the infiltrated binder foam board is maintained until the binder foam has its own rigidity.

A continuous manufacturing process can be achieved particularly easily when the binder foam is applied to the continuously supplied loose wood mass in the form of a strip and then infiltrates into the loose wood mass (up to the desired final board dimension) when the loose wood mass is compacted.

A further optimization of this method is that the binder foam is fed between two continuously fed bands of loose wood mass and both bands are then brought together into one loose wood mass while simultaneously infiltrating the binder foam and then compacted into a single board.

Thus, in this case, the foam is pushed into the loose wood mass almost ** isotropically "on one side and the other, whereby a single board is formed from both parts.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail below with reference to the accompanying drawing, in which: FIG. 1 shows the structure of a lightweight wood-based board according to the prior art, FIG. 2 shows a structure of a lightweight wood board according to the invention, and FIG. 3 shows a schematic process for the production of a lightweight wood board according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

A first loose wood mass 12A is fed to the first conveyor belt 10 in the direction of the arrow T.

A second conveyor belt 14 is provided spaced therefrom, on which a binder foam 17 is supplied, which is passed to the first loose wood mass 12A at the end of the second conveyor belt 14.

Again, at a certain distance above the binder foam 17, a third conveyor belt 16 is provided on which a second loose wood mass 12B is fed. which is transferred to the first loose wood mass 12A and the underlying binder foam 17 thereon, whereby the first infiltration of the binder foam 17 into both loose wood masses 12A occurs. 12B (see arrow I).

Then take a stream of material. composed of two loose wood materials 12A. 12B and the binder foam 17 therebetween, densify continuously between the schematically indicated rollers 18, during which the binder foam 17 enters the hollow spaces in the loose wood mass 12A. 12B and encapsulates the surface of the individual wood wool chips and fills the pores between the chips.

The densification is then carried out to the desired schematically indicated final dimension 20 until the binder foam 17 is solidified so that the lightweight wood wool board produced has sufficient intrinsic stability to be removed and further processed. Other operations include, in particular, cutting to the desired dimensions, possibly also painting the surface and / or making the connecting parts by gluing further plates or the like.

Claims (9)

PATENT CLAIMS 1. Light wood wool board p A skeleton of densified wood wool with open leeks, at Som 1.2 wood wool particles are provided with a binder coating on their surface, characterized in that Se 1.3 the coating has a foam-like structure which extends at least partially into the pores of the lightweight wood wool board; and 1.4, during the forming of the lightweight wood wool board, it was introduced into the molded loose wood mass by the infiltration of the connective foam while reducing the volume. Lightweight board according to claim 1, characterized in that the pore space in the carcass of densified wood wool particles is completely filled with hardened binder foam. Lightweight board according to claim 1 or 2, characterized in that the hardened binder foam has a density of 100 to 700 g / l. Lightweight board according to one of Claims 1 to 3, characterized in that the hardened binder foam has pores with a mean diameter of 0.2 to 5 mm. Light board according to one of Claims 1 to 4, characterized in that the weight ratio wood wool: the binder foam is 1: 6 to 2 ^: 1. Lightweight board according to one of claims 1 to 5, characterized in that it is provided with a cured binder foam coating covering the lightweight wood wool board surfaces. - 10 TM Zi3. - ° | Γ Method for producing a lightweight wood wool board according to one of claims 1 to 6, with the following operations 7.1. Bonding foam is applied to at least one surface portion of the loose wood mass; 7.2 the binder foam then infiltrates into it, while reducing the volume of free wood mass to the desired final dimension of the light wood board, 7.3 the compacted lightweight wood wool board with infiltrated join iv foam keep e with stable volume up to achievement own stiffness i C po hardening connective foam) • 8. Method according to claim 7, you from us j ú c i sa in that the binder foam is applied to the continuously fed loose wood mass in the form of a belt and then infiltrates into the desired final dimension of the light wood wool board as it compacts the loose wood mass. Method according to claim 7 or 8, characterized in that the binder foam is fed between two loose wood masses continuously fed in the form of strips and these strips are then brought together and compacted to the desired wood mass while the binder foam is infiltrated into the loose wood mass. final dimension of the light board. Method according to one of Claims 7 to 9, characterized in that a binder foam is used which contains substances which change the curing time and / or the porous structure.