DE-102025000850-B4 - Method for producing a composite material based on wood waste

Abstract

A method for producing a composite material based on wood waste, from particles of a lignocellulose substance obtained from softwood, characterized in that - the sawn timber, namely particles of a lignocellulose substance obtained from softwood, are planed with a four-sided planing machine, - the resulting shavings are transported to a storage silo via a compressed air system, - then the chips are conveyed from the silo to a sorting machine whose rollers have a rotational speed of 100-130, preferably 115 revolutions per minute, until a chip mixture is obtained, - whereupon the sorted chips are transported to a horizontal mixer at a rate of 20 m³ /h, - whereupon a working fluid in the form of a mixture consisting of water, ammonium sulfate and boric acid in a ratio of 35.3 to 41.2 parts water, 1.0 to 1.53 parts ammonium sulfate, 0.29 to 0.41 parts boric acid, preferably in a ratio of 37.2 : 1.2 : 0.35 and in an amount of 25 to 35, preferably 32 liters of the mixture per 1 cubic meter of chips is added, - then the whole thing is mixed at a shaft speed of 2-5, preferably 3 min/ m³ until the mixture is homogeneous, - and then the mixture is dried at a temperature of 45-60, preferably 55°C in a tunnel dryer until a composite material is obtained, consisting of 97-98%, preferably 98% wood chips; 0.8-1.5%, preferably 1.0% ammonium sulfate (NH 4 ) 2 SO 4 ; 0.2-0.5%, preferably 0.5% boric acid H 3 BO 3 ; and having a moisture content of 12-15%, preferably 12.5%.

Inventors

• Tim Kirchhoff

Assignees

• DOMAT SPÓŁKA Z OGRANICZONA ODPOWIEDZIALNOŚCIA
• Holz und Raum GmbH & Co. KG

Dates

Publication Date

20260513

Application Date

20250311

Priority Date

20240326

Claims (1)

1. A process for producing a composite material based on wood waste, from particles of a lignocellulose derived from softwood, characterized in that: - the sawn wood, namely particles of a lignocellulose derived from softwood, is planed with a four-sided planer; - the resulting chips are conveyed via a compressed air system to a storage silo; - the chips are then conveyed from the silo to a sorting machine, the rollers of which have a rotational speed of 100-130, preferably 115 revolutions per minute, until a chip mixture is obtained; - whereupon the sorted chips are transported at a rate of 20 m³ /h to a horizontal mixer; - whereupon a working fluid in the form of a mixture consisting of water, ammonium sulfate, and boric acid in a ratio of 35.3 to 41.2 parts water, 1.0 to 1.53 parts ammonium sulfate, and 0.29 to 0.41 parts boric acid, preferably in a ratio of 37.2 : 1.2 : 0.35 and in an amount of 25 to 35, preferably 32 liters of the mixture is added to 1 cubic meter of chips, - then the whole is mixed at a shaft speed of 2-5, preferably 3 min/ m³ until the mixture is homogeneous, - and then the mixture is dried at a temperature of 45-60, preferably 55°C in a tunnel dryer until a composite material is obtained, which consists of 97-98%, preferably 98% wood chips; 0.8-1.5%, preferably 1.0% ammonium sulfate ( NH₄ ) ₂SO₄ ; 0.2-0.5%, preferably 0.5% boric acid ( H₃BO₃ ) ; and which has a moisture content of 12-15 % , preferably 12.5%.

Description

The invention relates to a method for producing a composite material based on wood waste that meets the requirements for fire resistance and resistance to biocorrosion and that is used as insulating material for building walls and partition walls. Modern and ecological thermal insulation is designed to be environmentally friendly and improve indoor air quality. Increasing emphasis is being placed on insulation materials of organic origin, made from renewable raw materials such as wood chips, wood fibers, wood wool, cork, flax, hemp, sheep's wool, cellulose, reeds, and straw. These materials meet almost 100% of the requirements for sustainable development. The main advantages of thermal insulation made from natural raw materials include: protection of natural resources; environmentally friendly production; a balanced, almost closed CO2 balance (during their growth, the plants absorb as much CO2 from the atmosphere as is released when the waste from these materials is disposed of); energy savings (low energy consumption is required to produce this type of insulation); no pollutant emissions into the atmosphere during use, waste disposal, and processing of the material; easy waste disposal; and short transport routes (regional materials). These insulation materials are characterized by excellent thermal and moisture properties: they are vapor-permeable, have good thermal capacity, and can transport moisture within the material without reducing its thermal performance, as evidenced by their high sorption capacity. Such solutions ensure a stable microclimate indoors, both in winter and summer. To give these materials additional functionality, flame retardants, fire-retardant agents, and other substances that increase their resistance to biocorrosion can be added. During appropriate technological processes, the aforementioned raw materials are prepared accordingly, including drying, grinding, modification, pressing, or thickening. Despite the various additives and modification processes, these insulating materials remain harmless to human health and pose no risk to the surrounding environment. Their excellent acoustic insulation is another significant advantage. From the patent application WO 00/ 21 743A1 Reinforced composite materials are known which contain cellulose fibers dispersed in a matrix, wherein the matrix contains a polymerized material, preferably a thermoplastic with a melting point above 180°C, wherein the purity of the cellulose fibers with respect to alpha-cellulose is above 80 wt.%. The invention also includes methods for the production and application of composite materials. The patent specification PL 187 621 B1 Describes a method for manufacturing noise-reducing panels made of wood-concrete – especially for freestanding walls protecting against traffic noise, for panels whose outer surface has parallel grooves with symmetrically outwardly diverging side walls, in which a mass containing a cellulose filler mineralized with calcium chloride, as well as cement paste, is prepared, then the panel is formed using a vibratory-pressure process, wherein softwood is used as the cellulose filler, which is mechanically crushed into rods whose length is 0.4 to 0.9 times the dimension of the shortest side of the polygonal line marking the outline of the cross-section of the grooved panel, except for the side that forms the bottom of the groove, wherein the cross-section of the rods is 2 to 6 mm and their moisture content is not more than 20%, wherein the mass from which the panel is formed comprises the following components in weight proportions: rod-shaped cellulose filler in a quantity of 100 to 140, Portland cement 180 to 220, calcium chloride CaCl2 5 to 8, plasticizer 0.5 to 1.5 and water in an amount of 80 to 120 parts by weight. From the patent specification PL 174 863 B1 A method for preserving composite materials based on wood, wood-based materials and wood-like materials, as well as other materials, is known, which consists of defining points for the insertion of elements on the surface of an object to be treated, in particular a corroded object, at an angle of 0 to 60° to the horizontal plane, through which injection material is pressed under pressure, most preferably in the form of two-component epoxy resin, whereupon, after it has completely solidified, the outer surfaces of the resulting composite material are subjected to an impregnating-penetrating process, wherein the mutual distance between the individual points is smaller than the smaller side or the radius of the object to be treated, and the distance of the outermost points from the edge of the object is less than half the distance between them. A method for manufacturing a wood-based building panel according to patent specification PL/ EP 3802034 T3 This includes the following phases: providing wood chips; reducing wood chips to wood fibers in a refiner for 3 to 20 minutes under a pressure of 4 to 16 bar; gluing of Wood fibers with phe