Wood fiber insulating panel or mat

[0001] The present invention relates to a wood fiber insulation board or mat with improved properties.

[0002] A method for producing wood plastic insulation boards or mats is known. It is a method of wet production of insulation boards or mats made of wood material. The plates or mats produced in this way are relatively thin and the production costs are high, especially the drying costs are high.

[0003] Mats made of wood fibers or other fibrous natural products in combination with plastic fibers are also known. These mats are made in carding machines known from the textile industry. Also these mats have only a small thickness. If thicker boards need to be obtained, several boards are stacked on top of each other. [0004] DE 100 56 829 discloses a method for producing boards or insulating mats from wood fibers and plastic fibers having a thickness of about 20 mm produced in one operation. The wood fibers are mixed, in the desired ratio, with thermally activated synthetic fibers or with adhesive particles or with biologically degradable synthetic binding fibers and a single layer is applied to the mesh and with the help of a second mesh located on the first mesh is compacted or calibrated and finally cured in the heater.

[0005] Insulation boards made of wood fiber are characterized by a layered structure, because the fibers, when applied to the mesh tape, are arranged more or less evenly in one direction one above the other, which is known in the process of making MDF boards.

[0006] Such panels used for insulation or for making panels have low transverse tensile strength. The individual layers of the insulation board can easily separate.

[0007] In order to increase the lateral tensile strength, in the plate making process, the starting material is applied in several layers, the direction of application of the individual layers is rotated by 90 °. The product thus obtained is compressed. This is how known OSB (Oriented-Strands-Board) are produced. Such a product can also be obtained using conventional production methods. The produced mass is lightly pressed to the conveyor belt, and in the further manufacturing process it is cut into specific sections, which are stacked on top of each other, rotated 90 ° relative to each other and finally pressed. The product manufactured in this way is characterized by increased transverse tensile strength, however, this method of production is time consuming and requires high expenditure on installation.

[0008] The object of the invention is a method for producing insulating boards or mats of wood material of considerable thickness and good resistance to transverse stretching and pressure, as well as high density.

[0009] This object is achieved according to the features set out in the claims. Detailed features are presented in dependent claims 2 to 13.

[0010] Wood fiber insulation boards or mats are characterized by the spatial distribution of wood fibers as well as binding fibers and have a thickness of 3 to 350 mm and a density of 20 to 300 kg / m³. For the production of wood fiber insulation boards or mats according to the invention, known nonwoven fabric making devices are used, e.g. adapted DOA A-4600 devices.

[0011] For the production of insulation boards or mats of wood material according to the invention, wood fibers with a moisture content of 7 to 16%, in particular of up to 14%, are used.

[0012] Wood fibers produced in a cone mill in a known manner from wood, saturated with anti-inflammatory and / or hydrophobic agents in an amount of 8 to 30%, especially 10 to 20% and dried to achieve the desired humidity are used, while at the same time being eliminated dust and fibers too short or of a diameter.

[0013] In the production of insulating boards or mats of wood material, impregnation with anti-flammable and hydrophobic agents and drying of the wood fibers is carried out separately.

[0014] In addition to wood fibers, other natural fibers such as hemp, flax, sisal can also be used, while the properties of the wood panels or mats of the invention are achieved.

[0015] Depending on the desired composition, individual components are weighed in individual weighing devices and blown into the tank via a conduit.

[0016] To make the wood panels or insulation mats of the invention, a blend is used, consisting of 95 to 80% wood fibers and 5 to 20% binding fibers, the ratio being most preferably 90 to 10%. In this mixture, it is possible to replace 30% of wood fibers with other natural fibers.

[0017] The amount of fiber mixture applied to the first conveyor belt depends on the desired thickness and density of the wood board or mat, with a density of 20 to 300 kg / m³. The nonwoven thus obtained contains three-dimensional fibers.

[0018] To increase the compressive strength, a thermally activated synthetic granulate is applied to the nonwoven fabric. Granules obtained from the recycling of synthetic products are particularly useful for this purpose. Granules are also used, consisting of a thermally curable core and surrounding synthetic resin, which soften under the influence of temperature in the heating zone. The synthetic granulate can be added to the fiber mixture in an amount of 5 to 45%, especially in an amount of 10 to 40%, and most preferably in an amount of 22 to 37%. At the end of the first conveyor belt, the resulting nonwoven fabric is comminuted. The mix is ​​applied to a second conveyor belt, the fibers being arranged in three dimensions in an amount that allows obtaining the required layer thickness. The thickness of the mat is from 3 to 400 mm.

[0019] The continuous mat is covered on one side or on both sides with a fabric or nonwoven made of organic, inorganic or natural fibers. Covering tapes made of cellulose or foil are also possible. The fabric, non-woven fabric or tapes have a structure or are perforated. It is possible to dye them. As a result, the wood panels or mats of the invention obtain the desired properties. [0020] The mat is then introduced into the tunnel kiln and is heated and cooled. The oven temperature is adequate to soften the binding fibers and activate them. The temperature in the heating zone is 130 to 200 ° C, especially 160 to 185 ° C. Thanks to this, the binding fibers and synthetic granules connect internally with the wood fibers and possibly with the fabric or foil.

[0021] A calibration zone is connected to the heating zone of the oven in which the thickness of the mat is equalized to achieve the final thickness of the plate or mat of the invention. The mat has a thickness of 3 to 350 mm, especially 4 to

250 mm.

[0022] After calibration, the mat is transferred from the heating furnace to the cooling zone, where the final processing takes place to obtain the desired wood panels or insulation mats according to the invention. The edges of the mat are hemmed and it is divided along and / or across.

[0023] Plates or mats made of wood material have a thickness of 3 to 350 mm, especially 4 to 250 mm, and a density of 20 to 300 kg / m³. In addition, they have increased transverse tensile and pressure resistance.

[0024] The wood plastic insulating boards or mats according to the invention are used as acoustic insulating boards, as foot damping mats for laminate and parquet floors, as anti-trampling insulating boards, as thermal insulation boards, as internal rafter insulation boards. Additional covering of one or both sides with a non-woven fabric, organic, inorganic or other natural fiber cloth or foil, these coatings having the structure or can be perforated and dyed, significantly increases the range of uses of the wooden boards or insulating mats according to the invention.

[0025] The invention will be explained based on examples, examples 1 - 6 and 9 not partly forming the invention.

Example 1 [0026] 10 parts of bonding fibers and 90 parts of wood fibers, saturated with flame retardant, are used to make the wood insulating board, they are mixed and applied from the tank evenly to the first conveyor belt, so that the density is 30 to 60 kg / m2³, especially from 35 to 45 kg / m2³. From the end of the first conveyor belt, a 60 to 250 mm thick nonwoven fabric is transferred to a second conveyor belt and the continuous mat thus obtained is transferred to a tunnel kiln. After leaving the heating zone, the mat is not compacted and is relatively uniformly transferred to the cooling zone, and then divided into the desired dimensions.

Example 2 [0027] For the production of a wood insulating board, used as an acoustic insulating board, from the material described in example 1, the material on the second conveyor belt is swollen and after obtaining the required thickness, is covered on one side with a perforated nonwoven tape. In the tunnel kiln, the binding fibers are combined with wood fibers and a wood plastic insulation board is formed in combination with the nonwoven.

Example 3 [0028] 88 parts of wood fibers mixed with 12 parts of binding fibers are used for the production of absorbers or resonators, and they are applied to the first conveyor belt in an amount such that a mat with a density of 35 to 100 kg / m³. After comminution of the obtained nonwoven fabric at the end of the first conveyor belt, the material is applied to the second conveyor belt to obtain a layer 30 to 120 mm thick. The mat obtained is further processed as described in example 1.

Example 4 [0029] For the production of wood fibers used in acoustics, a mixture of 10 parts of binding fibers, 75 parts of wood fibers and 15 parts of flax fibers is used, after which the mixture is evenly applied to the first conveyor belt from the tank and a product is obtained final density from 35 to 130 kg / m³. After the non-woven fabric is crushed at the end of the first conveyor belt and the material is mixed again, the non-woven fabric is applied to the second conveyor belt to a thickness of 4 to 200 mm. Further processing of the obtained mat is carried out as described in Example 1.

Example 5 [0030] For the production of wood fiber and hemp fiber insulation boards, a mixture of 12 parts of a binding trawl, 60 parts of wood fibers and 28 parts of hemp fibers is used. The material thus obtained is applied evenly to the first conveyor belt from the tank, obtaining a density of 25 to 50 kg / m³, especially from 25 to 40 kg / m2³. After mixing the ingredients again, it is evenly transferred to the second conveyor belt. The speed of the second conveyor belt is selected to obtain a mat with a thickness of 80 to 250 mm. Further processing is carried out as described in Example 1.

[0031] All the insulation boards or mats shown in the examples are characterized by high transverse tensile strength, higher than the previously known wood boards or insulation mats.

Example 6 [0032] For the production of wood-insulating mats, used as noise-damping mats for laminate or parquet floors, a mixture of 11 parts of binding fibers and 89 parts of wood fibers is used, which is introduced into the tank. By blowing this mixture from the tank onto the first conveyor belt, a uniform nonwoven fabric with a density of 150 to 280 kg / m is obtained.³, especially from 150 to 180 kg / m2³. A mixer is placed along the entire width of the first conveyor belt, by means of which, before re-mixing the obtained nonwoven fabric, a synthetic granulate is obtained, obtained from recycling of plastic products and the nonwoven fabric is transferred to the second conveyor belt, on which the ratio of wood fibers to binding fibers and for granules is 55: 7; 38. The thickness of the mat on the second conveyor belt is from 5 to 10 mm. The resulting continuous mat is transferred on a second conveyor belt to a tunnel kiln, in which the heating zone is heated with hot air to a temperature of 170 to 180 ° C and shifted through the calibration zone. There is slight compaction and the mat eventually reaches a thickness of 3 to 8 mm. The mats have good transverse tensile strength and increased pressure resistance.

Example 7 [0033] 9 parts of binding fibers and 75 parts of wood fibers and 17 parts of hemp fibers are introduced into the tank. From the tank, the fiber mixture is applied to the first conveyor belt so that the nonwoven fabric obtains a density of 130 to 220 kg / m³, from 150 to 180 kg / m2³. After the nonwoven fabric is made with a pulverizer, granules are added, consisting of a thermally hardened core and a synthetic resin that softens in the heating zone. The amount of granulate added is so high that for two parts of the fiber mixture there is one part of granulate. At the end of the first conveyor belt, the fiber mixture is mixed with the granulate and transferred to the second conveyor belt. The speed of the second conveyor belt is chosen so that the continuous mat has a thickness of 20 to 22 mm. One side of the mat has a profiled cellulose fabric that covers the entire width of the mat. The product thus obtained is sent to a tunnel kiln and heated to 170 ° C. At this temperature, the product is moved through the calibration rollers and is finally compressed to a thickness of 8 to 15 mm. Such wood insulating boards are used as backing boards in dry rooms.

Example 8 [0034] For the production of wood insulation boards that are used to insulate rafters and which do not need to be trampled, a mixture of 11 parts of binding fibers and 89 parts of wood fibers is introduced into the tank. The tank and mixture is applied to the first conveyor belt in such an amount that the final product has a density of 70 to 150 kg / m³, especially from 100 to 140 kg / m2³. To the non-woven fabric thus obtained, a granulate is added by means of a pulverizer, consisting of a heat-resistant core and a softening coating in the heating zone and / or consisting of a synthetic resin granulate obtained during the recycling of plastic objects. The amount of granulate introduced is 28 parts in relation to 72 parts of the fiber mixture.

[0035] The shredded nonwoven with granulate and mixed well with it is fed onto a second conveyor belt. The speed of the second conveyor belt is selected so that the continuous mat is 65 to 180 mm thick. The mat has a tight, moisture-resistant film on one side and a non-woven fabric on the other. The mat thus covered on both sides is transferred by means of a second conveyor belt to a tunnel kiln, in which the heating zone is heated to 175 ° C, and then compressed in the calibration zone to a thickness of 60 to 160 mm.

[0036] In the heating and calibration zone, due to the softening of the binding fibers and the granulate, a matrix for wood fibers is formed, sufficient to connect the film or nonwoven fabric.

Example 9 [0037] For the production of WDVS support plates, 12 parts of binding fibers and 88 parts of wood fibers are introduced into the tank. It is processed as described in example 8, with the difference that the density is from 80 to 140 kg / m³, especially from 95 to 105 kg / m2³ and that granules are added in a ratio of 37 parts granules to 63 parts fiber mix. After thoroughly mixing the fiber mixture with the granulate at the end of the first conveyor belt, the mixture is transferred to the second conveyor belt. The speed of the second conveyor belt is selected to obtain a continuous mat with a thickness of 75 to 280 mm. After entering the tunnel kiln, it is heated to 175 ° C. By means of calibration rollers its thickness is obtained from 60 to 200 mm. The manufactured panels have excellent compressive strength and very good transverse tensile strength.

Example 10 [0038] A blend consisting of 13 parts of binding fibers and 78 parts of wood fibers and 9 parts of flax fibers is used for the production of puncture-resistant wood-fiber insulation boards, which mixture is introduced into the tank. From the tank, the fiber mixture is fed to the first conveyor belt in such a quantity that it is possible to obtain a density of 170 to 270 kg / m³, especially from 230 to 250 kg / m2³. The non-woven fabric thus formed, on the first conveyor belt is applied granulate obtained from recycling, in a double system, plastic objects, in an amount of 36 parts of granules to 64 parts of a mixture of fibers.

[0039] In order to achieve an even distribution of granules in the fiber mixture, the nonwoven at the end of the first conveyor belt is comminuted and thoroughly mixed, and then transferred to the second conveyor belt. The rotation speed of the second conveyor belt is selected such that the continuous mat has a thickness of 25 to 90 mm.

[0040] The mat has on one side a disordered fiber structure over its entire width.

[0041] The product thus obtained is transferred to a tunnel kiln and is heated to 175 to 185 ° C in the heating zone. In the calibration zone, it is compressed to a thickness of 15 to 60 mm, and then cooled. The spatial trawl system shall also be maintained after calibration. The mat is characterized by high compressive strength and increased transverse tensile strength.