EP2355965B1 - Composition and process for producing a wooden or wood fibre plate - Google Patents

Description

FIELD OF THE INVENTION

The present invention relates to a composition for wood and wood fiber boards, wood or wood fiber boards themselves and a method for producing wood or wood fiber boards.

STATE OF THE ART

Wood-based materials made of chipboard or fiber material are used, for example, in the construction furniture and furnishing industry. In the field of wood fiber boards, a distinction is made between fiber insulation boards (HFD), hardboard (HFH, KH) and MDF boards. These are made of finely shredded, mainly bark-free softwood and by a gentle compression in the longitudinal and transverse direction. The edges are smooth and firm and can be profiled without special edge banding.

In addition, there are still chipboard or flat press plates, which consist of wood chips of various sizes, which are produced with synthetic resin adhesive under the supply of heat in the flat pressing process. The chips are aligned in the direction of the plate plane.

The area of use of the wood fiber boards is similar to that of the chipboard, however, can be profiled by the fine, almost homogeneous structure of the wood fiber board, the edges and surfaces and then painted. The need for gluing, as would be the case with flat-pressed plates, is eliminated.

At present, only wood fibers or lignocellulose-containing fiber material are used for the production of wood fiber boards or flat pressed boards. By means of heat, moisture and mechanical pressure forces in fiberizing plants, the wood chips are processed for a production of the plates.
In the known from the prior art wood and wood fiber boards only wood is used as the starting material. The resources of this natural product are limited and also for reasons of nature conservation it is desirable to be able to use alternative raw materials. In addition, it is also interesting for cost reasons to look for alternatives for the production of corresponding wood or wood fiber boards.

The DE 10330756 A1 discloses a process for the production of a solid for the production of molded parts, in which a binder is added to the pulp and pressed into a molded part under the application of heat. The disclosed method is characterized in that a particle or fiber mat of a first group of particles or fibers is admixed with a proportion of plastic particles and / or plastic fibers whose particle size corresponds approximately to the particle size of the particles or fibers of the first group. The plastic particles and / or fibers are obtained by crushing and / or fibring of pure or mixed plastic agglomerates in a disc refiner, whereby the disc refiner is supplied with water during the comminution process.

The DE 10 2004 008 827 A1 discloses a plate, a molding and a cover layer of a wood material, wherein a wood material is provided, which is ground or contains shredded agglomerate of plastics from the waste disposal. According to the disclosure of DE 10 2004 008 827 A1 in the plastic particles used pure plastics, mixed and / or film plastics from collection systems or pure or mixed plastics from recycling systems.

The US 2006/0121261 A1 discloses a fiberboard wherein synthetic particles or fibers are mixed into the wood fibers or wood flakes. The ingredients are pressed into a plate under heat and some of the wood fibers or flakes are replaced by ground or shredded agglomerates of mixed synthetic waste material. According to the disclosure of US 2006/0121261 A1 If the synthetic waste materials are plastic or plastic mixtures.
The WO 2008/114103 A1 discloses the admixture of cork to wood raw material for the production of wood fiber boards. Cork is the material of the bark of a cork oak and thus another raw material, which is to be assigned as a special part of a tree the range of wood raw materials.

The DE 10 2004 011 931 A1 discloses an insulating board made of a wood-material-binder fiber mixture and a method for producing an insulating board, in which the mixture is added to an additive with a thermally stable core and a thermally activatable coating and activated under heat. The main idea of this disclosure is the ability to selectively achieve a thermal activation for bonding the ingredients. The use of alternative raw materials or raw material compositions for the manufacture of wood or fiberboard does not disclose this document.

The DE 10 2006 054 204 describes a technology in which pure plastics are used, which are then to be melted, which is to be effected by an extruder. It does not disclose methods dealing with alternative ingredients in the starting material for making a plate.

In the DE 103 54 394 Alwird a special binder and its use for the bonding of wood materials and / or fiber materials apparently. The subject of this document is directed to the compounding of the raw materials of such plates and is not concerned with alternative additives to be used in the manufacture of wood or fiberboard.

The DE 14 53 374 A describes a method for producing composite bodies. In this case, the base material is compressed by admixing thermoplastic films and the action of pressure and heat. Accordingly, this reference is concerned with the compounding of the raw materials of a board made using pressure and heat, but not with the use of alternative combinations of raw materials.

The DE 44 10 576 A1 deals with the production of panels, which consists of a mixture of plastic, wood, semi-wood and recycled material. In order to produce such plates, the plastic components must be fused and pressed under special process conditions. A disadvantage of this method is that the required parameters in terms of pressure and temperature can not be achieved on conventional systems in use, without having to make major and costly adjustments to the equipment.

In the future, it can be assumed that the raw material wood will continue to shrink, be it as fresh or as waste wood. For these reasons, there is a need for alternative sources of material and also methods of making wood or fiberboard.

Basically, however, it should be noted that the applicable country-specific standards, such. B. according to DIN or EN for the production of the plates.

SUMMARY OF THE INVENTION

The object of the present invention is therefore to provide a composition for the production of a wood or wood fiber board, which can be used to produce a wood or wood fiber board, the resulting plate the requirements of the corresponding country-specific standards, for example, according to the German or European EN or DIN is sufficient. Furthermore, a manufacturing method using the composition and the wood or wood fiber boards are the subject of the invention.

According to the invention, there is provided a composition comprising a pulp, a binder, a curing accelerator and a paraffin emulsion, wherein the pulp comprises at least 5% wood extraneous raw materials consisting of a mixture of 0-40% inorganic portions, 5-81% synthetic organic portions and / or 0-22.5% of decomposable organic fractions, the proportions used in each case adding up to 100% foreign wood raw material. This composition is suitable for the production of wood or wood fiber boards, which are not only made entirely of wood.

For a composition according to the invention, it is provided that the wood-foreign substances are solids, in particular also mixtures of different solids. The solids are organic or inorganic solids, wherein the organic substances may be synthetically produced, such as plastics or may be decomposable as biological substances such. As proteins, sugars or fats, oils or natural fibers.

It is envisaged that the non-wood raw materials as part of the pulp is a mixture consisting of 0-40% inorganic portions, 5-100% synthetic organic portions and / or 0-95% decomposable organic portions, wherein the proportions used each add up to 100% to the wood extraneous raw material.

Further, a composition may additionally contain urea and / or lignin sulfonates and the binder may be urea-formaldehyde, melamine or phenolic resin or a combination thereof.

1. a) Herstellen einer Rohstoffmischung zur Aufbereitung als Faserstoff, wobei der Faserstoff einen Holzrohstoff und wenigstens 5% holzfremde Rohstoffe, bestehend aus einer Mischung von 0 - 40% anorganischen Anteilen, 5 - 81% synthetisch organischen Anteilen und/oder 0 - 22,5% verrottbaren organischen Anteilen, wobei sich die verwendeten Anteile jeweils zu 100% holzfremden Rohstoff addieren, enthält;
2. b) Zerfaserung der Rohstoffmischung nach dem thermochemischen Verfahren;
3. c) Trocknung des Faserstoffs;
4. d) Beleimung des Faserstoffs, bevorzugt im Blender-Verfahren;
5. e) Heißverpressen des beleimten Faserstoffs; und
6. f) Besäumen der Platten und Schleifen auf eine definierte Plattenstärke.

Furthermore, a method for producing a wood or wood fiber board is an object of the present invention, comprising:

1. a) producing a raw material mixture for processing as a fibrous material, the fibrous material comprising a wood raw material and at least 5% wood-foreign raw materials, consisting of a mixture of 0-40% inorganic portions, 5-81% synthetic organic portions and / or 0-22.5% decomposable organic fractions, the proportions used each add up to 100% wood extraneous raw material contains;
2. b) defibration of the raw material mixture according to the thermochemical process;
3. c) drying the pulp;
4. d) gluing of the pulp, preferably in the blender process;
5. e) hot-pressing the glued pulp; and
6. f) trimming the plates and loops to a defined plate thickness.

For the process it is provided that urea-formaldehyde, melamine or phenolic resin or a combination thereof can be used as binder, wherein the raw material mixture with the use of urea-formaldehyde resin to an acidic pH, preferably between 5 to 5.8, is set. In principle, the use of other binders or adhesives of the invention is also included.

It is further provided for the process that non-wood raw materials can be used as part of the pulp, which consist of a mixture of 0-40% inorganic portions, 5-100% synthetic organic portions and / or 0-95% decomposable organic portions the proportions used in each case add up to 100% wood-foreign raw material.

DESCRIPTION OF THE FIGURES

• Fig. 1 Scheme for carrying out the method according to the invention.
• Fig. 2 Wood or wood fiber board consisting of at least 5% wood-foreign raw material.

FIG. 1 shows the sequence of a method for producing a wood or wood fiber board according to the invention. In this case, a wood raw material 10, for example chips of a softwood, and a wood-external raw material 20 are used to produce a composition for the pulp 20.

The mixture is then defibered 40 and the resulting pulp dried 40. After gluing the pulp 60, the pressing of the pulp takes place at preferably 150-250 ° C and a pressing time of 15-25 s / mm ² .

Finally, the plates are trimmed and ground to a uniform thickness.

FIG. 2 shows a portion of a wood or fiberboard 21 made using at least 5% non-wood raw material and wood furnish.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be described below with reference to embodiments, without being limited thereto. This applies in particular with regard to the materials used.

example 1

A medium-density fiberboard (MDF) made of pine wood and a raw material containing non-wood ingredients was produced. After production, it was checked whether the resulting MDF board, which is not completely made of wood, complies with the required regulations regarding the mechanical property of the transverse tensile strength as well as the material properties of thickness swelling and water absorption after 2 and 24 hours.

To compare the resulting properties, an MDF board was made exclusively from pine wood chips and an MDF board, which consists of pine wood chips and a raw material with non-woody ingredients in a mixing ratio of 80% pine wood pulp and 20% wood extraneous raw material. The data refer to the dry matter. For both types of MDF board, a UF resin 350 (BASF) was additionally used as binder.

From the pine wood chips or the pine wood pulp / raw material mixture fibers were produced by the thermomechanical process (TMP process). The digestion of the raw materials took place in a laboratory refiner plant with cooker and pipe dryer. The digestion temperature was at 5.0 ° C. at 150 ° C. and the digestion time was 5 minutes.

• ▪ Der Faserstoff wurde im Blender-Verfahrenin einem Trommelmischer beleimt.
• ▪ Als Bindemittel wurde ein Harnstoff-Formaldehydharz (UF-Harz K350) verwendet, wobei der Bindemittelaufwand 15% (Feststoff/Trockenmasse Faserstoff) betrug.
• ▪ Als Härtungsbeschleuniger wurde Ammoniumsulfat (2% Feststoff Härter/Festharz) eingesetzt..
• ▪ Es wurden 1,1% Parafinemulsion (Feststoff Paraffin bezogen auf Trockenmasse Faserstoff) verwendet, wobei die Paraffinemulsion zusammen mit dem UF-Harz auf den Faserstoff gegeben wurde.

Subsequently, the fibrous materials were dried in the drying oven at 65 ° C to a fiber moisture content of about 2% followed by drying in the tube dryer. The dried pulps were glued in a blender as follows:

• ▪ The pulp was glued in the Blender process in a drum mixer.
• ▪ The binder used was a urea-formaldehyde resin (UF resin K350), with a binder consumption of 15% (solid / dry pulp).
• ▪ Ammonium sulphate (2% solids hardener / solid resin) was used as hardening accelerator.
• ▪ 1.1% paraffin emulsion (solid paraffin based on dry pulp solids) was used with the paraffin emulsion added to the pulp along with the UF resin.

Following the gluing of the raw materials, the respective material was hot-pressed into slabs. In this case, single-layer plates were produced with a plate thickness of 16 mm and a target density of 750 kg / m ³ . The pressing temperature was 200 ° C and the pressing time 15 s / mm plate thickness.

After production, the plates were trimmed and ground to 16 mm plate thickness. From the plates with different raw materials test specimens identical extent were created, which were conditioned in the normal climate to the equilibrium moisture content. Subsequently, the properties of transverse tensile strength were determined according to EN 319, thickness swelling after 2 and 24 hours according to EN 317 and water absorption after 2 and 24 hours. The results can be summarized in Table 1 as follows: <u> Table 1 </ u>: bulk density, transverse tensile strength, thickness swelling and water absorption fiber Bulk density kg / m ³ Transverse tensile strength N / mm ² Thickness swelling water absorption 2h% 24 hours % 2h% 24 hours % 100% pine 777 0.94 2.0 5.5 3.4 13.8 80% pine 20% non-wood raw material 783 0.80 2.8 11.3 18.1 43.5 Requirements according to DIN 622-5 for MDF boards with a thickness> 12 ... 19 mm > 0.55 <12

The results show that the thickness swelling is indeed significantly higher for the plates that were produced with the addition of wood-foreign substances, but they comply with the DIN standard 622-5. According to the greater thickness swelling, the plates with the raw material, which has foreign components, also increased water absorption.

Overall, the embodiment shows that an MDF board can be produced, which complies with the required standards, but is not 100% made of wood. Thus, the present invention provides an alternative to entirely wood panels, thereby conserving natural resources and providing a means for using other additives.

Analogous to the example shown above, further plates were produced in which a wood-foreign substance was used as the raw material for the production of the pulp. The wood foreign substance may have inorganic components, such as for example, salts, glass, metal, ceramics, etc. and / or synthetic organic substances such as plastics and / or decomposable organic substances such as natural fibers, fats, oils, sugars or proteins. The lists of the substances of the individual groups are only to be understood as exemplary and not exhaustive.

• 73% synthetisch organische Stoffe und 27% anorganische Stoffe
• 22,5% anorganische Stoffe, 55% synthetische organische Stoffe und 22,5% verrottbare organische Stoffe
• 40% anorganische Stoffe, 55% synthetische organische Stoffe und 5% verrottbare organische Stoffe
• 81% synthetische organische Stoffe und 19% anorganische Stoffe.

The following mixtures were used for the production of further boards using wood-foreign substances:

• 73% synthetic organic matter and 27% inorganic matter
• 22.5% inorganic substances, 55% synthetic organic substances and 22.5% decomposable organic substances
• 40% inorganic substances, 55% synthetic organic substances and 5% decomposable organic substances
• 81% synthetic organic matter and 19% inorganic matter.

In contrast to the revelations of DE 10 2004 011 931 A1 , of the DE 103 54 934 A1 or the DE 14 53 374 In the present disclosure is not the connection of the raw materials in the foreground, it is not necessary to merge plastics contained together. Rather, the method of the present disclosure contemplates that a mixed input stream may be used as a wood substitute in a standard MDF or particle board process. This has hitherto not been possible, since in this process, due to the mere mixing of wood with wood substitutes, subsequent bonding and pressing, just no corresponding stability and durability could be achieved, as shown in the above example.

The starting material is pretreated in a process of this invention such that it can be used as a wood substitute, leaving all common parameters in known standard processes. This means that the previously disclosed method can be applied to machines that are already in use and there is no need to make any special adjustment to reach particular pressures or temperatures.

A clear difference to DE 44 10 576 A1 is that the press temperatures are significantly lower in the process disclosed in this document. In a method according to this disclosure, a corresponding temperature is only required in order to produce a corresponding function of the standard binder, the UF glue. Temperature and pressure per se have no effect on the material or on the connection of the material with the corresponding binder.

In contrast to the revelation of DE 44 10 576 A1 , the existing standard processes for wood fiber board production can continue to be used, no new methods or devices must be installed and therefore no technical changes in the existing production process are made to allow the production of corresponding plates.

LIST OF REFERENCE NUMBERS

10

raw wood

20

non-wood raw material

21

Plate made of pressed fiber material with 5% non-wood raw material

30

Making the composition for the pulp

40

Defibering of the raw material

50

Drying of the pulp

60

Gluing the pulp

70

Pressing the pulp

80

Trimming and sanding the plates

Claims (8)

1. Composition comprising a fibre, a binder, an accelerator and optional a paraffin emulsion, wherein the fibre comprises a wood raw material and at least 5% of non-wood material, consisting of a mixture of 0 - 40% inorganic parts, 5 - 81% synthetic organic parts and/or 0 - 22.5% rottable organic parts, wherein the used parts add to 100% non-wood raw material.
2. Composition of claim 1, wherein the non-wood material are mixtures of different solid material.
3. Composition according to any one of the preceding claims, comprising additionally urea and/ or lignosulphonate.
4. Composition of any one of the preceding claims, wherein the binder is urea formaldehyde- , melamine- or phenolic-resin or a combination thereof.
5. Method for the manufacture of a wood or fibreboard, comprising:

   a. Manufacture of a raw material mixture for the preparation of a fibre, wherein the fibre comprises a wood raw material and at least 5% of non-wood material, consisting of a mixture of 0 - 40% inorganic parts, 5 - 81% synthetic organic parts and/or 0 - 22.5% rottable organic parts, wherein the used parts add to 100% non-wood raw material;

   b. Shredding of the raw material mixture with a thermodynamic process;

   c. Drying of fibre;

   d. Gluing of fibre, preferable in a blender process;

   e. Hot pressing of glued fibre; and

   f. Trimming of plates and grinding to defined panel thickness.
6. Method of claim 5, wherein the binder is urea formaldehyde-, melamine- or phenolic-resin or a combination thereof.
7. Method of claim 5 or 6, wherein the raw material mixture using urea formaldehyde resin is adjusted to an acidic pH between 5 to 5.8.
8. Method of any one of claims 5 to 7, using non-wood raw material as part of the fibre, consisting of a mixture of 0 - 40% inorganic parts, 5 - 100% synthetic organic parts and/or 0 - 95% rottable organic parts, wherein the used parts add to 100% non-wood raw material.

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