WALLBOARD AND METHOD OF MAKING AND USING SAME

Abstract

The invention relates to a material board (1) which comprises a core (2) and a first cover layer (3) and a second cover layer (4), each of which is formed by a mixture (7, 8) formed by lignin-containing particles (5, 6) and binder, which mixture is designed to form a solid body structure in a chemical binding process. The aim is to provide a material panel, which, for ecological and economical reasons, comprises a high proportion of particles based on annual plants and still exhibits good mechanical properties. Another object of the invention can be considered that of ensuring that the system load is kept relatively low during the production process. Another object can be considered that of keeping the proportion of stock removal low. According to the invention, at least 70%, preferably at least 80%, most preferably at least 90% of the particles (5) associated with the mixture (7) of the core (2) are obtained from annual plants, and at least 70%, preferably at least 80%, most preferably at least 90% of the particles (6) associated with the mixtures (8) of the two cover layers (3, 4) are obtained from perennial plants. The invention further relates to the use of a material board and to a method for producing a material board. Finally, the invention relates to a system for producing a material board.

Claims

1. In a wallboard comprising a core layer and first and second cover layers each formed from a mixture of a binder and lignin-containing particles and together formed into a solid body by a chemical and/or mechanical bonding process, the improvement wherein the particles of the mixture of the core are at least 70% from annual plants, and the particles of the mixtures of the two cover layers are at least 70% from perennial plants.

2. The wallboard according to claim 1, further comprising: an intermediate layer having a mixture formed from lignin-containing particles; and a binder between the core and at least one of the cover layers, the particles of the mixture of the intermediate layer being at least 5% from annual and perennial plants.

3. The wallboard according to claim 1, wherein the mixture of the core and the mixtures of the cover layers comprise binders from the same binder group.

4. The wallboard according to claim 1, wherein the core is an OSB layer.

5. The wallboard according to claim 1, wherein the core layer is an MDF or HDF layer.

6. The wallboard according to claim 1, wherein the core layer is a chip-layer.

7. The wallboard according to claim 1, wherein at least one of the cover layers is an OSB layer.

8. The wallboard according to claim 1, wherein at least one of the cover layers is an MDF or HDF layer.

9. The wallboard according to claim 1, wherein at least one of the cover layers is a chip layer.

10. The wallboard according to claim 1, wherein the core and the cover layers surrounding it are each formed from a uniform layer.

11. The wallboard according to claim 1, wherein at least two layers different layers is formed of particles different from the other of the two layers.

12. (canceled)

13. A method for making a wallboard comprising a core layer and a first and second cover layers each formed from a mixture of lignin-containing particles and a binder as a solid structure in a chemical and/or mechanical bonding process under the action of pressure and temperature, wherein in order to form the mixture of the core, particles are used that are at least 70% from annual plants, and particles used to form the mixture of the two cover layers are at least 70% from perennial plants.

14. The method according to claim 13, wherein, in order to form the solid structure of the wallboard, the mixture forming the core is supplied substantially free-flowing to the portion of the chemical bonding process under pressure and temperature influence, and the mixture forming at least one of the cover layers is supplied substantially flowable to the portion of the chemical bonding process under pressure and temperature influence.

15. The method according to claim 13, further comprising the step of; mixing the particles of the core and at least one of the cover layers are mixed during the chemical bonding process in such a way that an intermediate layer is formed whose mixture contains particles of annual plants and particles of perennial plants, the proportion of which on the mixture after completion of the chemical bonding process is at least 5%.

16. The method according to claim 13, wherein at least the core is supplied pre-compressed to the portion of the chemical bonding process under pressure and temperature influence.

17. (canceled)

18. In a system for making a wallboard, comprising at least one forming station for making a multilayer pressed-material mat on a forming belt and at least one press for pressing the pressed-material mat using pressure and heat to form the wallboard, the improvement wherein the forming station comprises a first applicator for applying at least one free-flowing, core-forming pressed-material mat layer and at least one second applicator for applying at least one flowable, cover-layer forming pressed-material mat layer.

Description

[0083] The invention is explained in the following with reference to a drawing showing only one embodiment. In the drawing:

[0084] FIG. 1 is a simple vertical section through a wood wallboard according to the invention;

[0085] FIG. 2 shows a system according to the invention for making a wallboard[; and

[0086] FIG. 3 is another vertical section through a wood wallboard according to the invention].

[0087] The drawing shows the method according to the invention for making a wallboard, the (wood) wallboard itself, and a system for making same.

[0088] Such (wood) wallboard 1 has a core or core layer 2 and a (e.g. upper) first cover layer 3 and a (e.g. lower) second cover layer 4, and particles 6 in the mixtures 8 forming the two cover layers 3, 4 are obtained at least 70%, preferably at least 80%, very preferably at least 90%, from perennial plants, while particles 5 in the mixture 7 of the core (2) are at least 70%, preferably at least 80%, very preferably at least 90%, from annual plants.

[0089] In the embodiment shown, the core layer 2 itself is in turn formed in multiple layers. It has an upper layer 2a, a middle layer 2b, and a lower layer 2c that here each consist of strands, but with different orientations. While the strands of the upper layer 2a and the lower layer 2c extend in the longitudinal production direction X or P, the strands of the middle layer 2b are substantially transverse to the longitudinal production direction X or P of the board and extend in the Y direction. This is merely indicated in simplified form in FIG. 1. However, the core can also be single-layered and/or in the form of another layer, for example as a chip layer or as an MDF/HDF layer.

[0090] A multilayer pressed-material mat T that is pressed by means of pressure and heat to form the sheet wallboard 1, is first produced in order to make such a flat wallboard 1.

[0091] Such a production method is explained in more detail with reference to FIG. 2. First, a multilayer pressed-material mat T is produced on a forming belt 13, and this pressed-material mat T has a (middle) core pressed-material layer 2′, an upper covering pressed-material layer 3′ and a lower covering pressed-material layer 4′. This multilayer pressed-material mat T produced on the forming belt 13 is introduced into a press 14 and pressed into the press 14 using pressure and heat to form the wallboard 1. In the illustrated embodiment, the press 14 is a continuously operating dual-belt press 14.

[0092] In the prior art, pressed-material mats are generally produced in a classic manner from spreadable, pourable particles in a molding station that contains a plurality of classical strewing heads, so that the individual layers are strewn successively onto the shaping belt 13.

[0093] In contrast, FIG. 2 shows a system that, in a manner according to the invention, does not produce at least one of the cover pressed-material layers 3′, 4′ from spreadable particles, but rather from a flowable particle-liquid mixture 8. The core-pressed-material layer 2′ is strewn in a conventional manner from a mixture of spreadable particles.

[0094] For this purpose, the system 12 according to the invention has a forming station 15 that has the first applicators 16 and second applicators 17. While the applicators 16 for the core-pressed-material layer 2′ can be designed as classic strewing heads, the applicators 17 for the upper pressed-material layers 3′, 4′ are designed for application from a flowable chip-liquid mixture 8. They can be, for example, extruders for generating and applying the particle-liquid mixture 8.

[0095] In this way, the lower cover pressed-material layer 3′ is first extruded onto the forming belt 13 in flowable form. The core-pressed-material layer 2′ with the first applicators 16 designed as strewing heads is strewn in a classic manner onto this lower cover pressed-material layer 3′. In this case, in the embodiment according to FIG. 2, a total of four strewing heads are indicated, specifically for making a multilayer correspondingly oriented core pressed-material layer 2′. Thus, the first strewing head strews the longitudinal-oriented strands for a lower layer of the core-pressed-material layer 2′, the second and third applicator 16 strews the transversely oriented strands for the central position of the core-pressed-material layer 2′, and finally the fourth applicator 16 strews the longitudinal-oriented strands for the upper layer of the core-pressed-material layer 2′. The last applicator 16 is followed by the applicator 17 for the upper pressed-material layer 4′, so that the upper pressed-material layer 4′ is extruded onto the core pressed-material layer 2′ in flowable form. The pressed-material mat 1′ produced in this way is subsequently introduced into the press 14 and pressed into the wallboard 1. Of course, further installation components can be arranged between the forming station 15 and the press 14, for example services for processing the mat, a pre-press and/or preheating device, detection devices for foreign bodies and/or false filling. Details are not shown.

[0096] Independent of the system shown in FIG. 2, wallboards according to the invention can have a core 2 and a first cover layer 3 and a second cover layer 4 that are each formed from lignin-containing particles 5, 6 and a mixture 7, 8 formed from lignin, forming a solid body in a chemical bonding process, and the particles 5 of the mixture 7 of the core 2 are at least 70%, preferably at least 80%, very preferably at least 90% are obtained from annual plants, and that the particles 6 of the mixtures 8 of the two cover layers 3, 4 are obtained at least 70%, preferably at least 80%, very preferably at least 90%, from perennial plants, but are also produced on conventional plants, both the core and the cover layers being built up one above the other in the strewing method.

[0097] The system shown in FIG. 2, however, is a particularly good setup for carrying out the method described and consequently also particularly good for making the intermediate layers 10, 11, shown in the wallboard of FIG. 3. The wallboard 1 from FIG. 3 otherwise corresponds in construction to the wallboard shown in FIG. 1.

TABLE-US-00001 LIST OF REFERENCE SIGNS 1 wallboard .sup. 1′ mat 2 core, (layer) .sup. 2′ core material layer  2a upper layer  2b middle layer  2c lower layer 3 (first) cover layer, (layer) .sup. 3′ (first) cover layer mat 4 (second) cover layer, (layer) .sup. 4′ (second) cover layer mat 5 particles 6 particles 7 mixture (forming core) 8 mixture (forming cover layer) 9 mixture (intermediate layer forming mixture) 10  (first) intermediate layer 11  (second) intermediate layer 12  plant 13  shaping band 14  press 15  forming station 16  first applicator 17  second applicator P board longitudinal direction X longitudinal direction Y transverse direction Z vertical direction