RU2164870C2 - Pressed wood material and method for its production - Google Patents

Abstract

FIELD: wood-working industry, applicable in production of pressed wood materials, for instance, wallboards. SUBSTANCE: pressed wood material has layers of large-sized wood particles interconnected by a binder. Enlarged fibrous wood elements of arbitrary lengths are used as large-sized wood particles. Each layer made of large-sized wood particles contains at the same time enlarged fibrous wood elements of different lengths. Large-sized wood particles are produced by splitting the bond between the fibres by means of mechanical deformation of the wood raw material in the transverse direction and its subsequent disassembly into enlarged fibrous wood elements on the boundaries of split bonds. EFFECT: simplified process, reduced expenditures on production, enhanced quality of produced material. 4 cl, 6 dwg, 2 ex

Description

 The invention relates to the woodworking industry and can be used in the production of pressed wood materials, for example wood boards.

 Known pressed wood material (fiberboard dry method), including wood particles in the form of fibers, interconnected by a binder (A.M. Kozachenko and B.D. Modlin. General technology for the production of wood boards, M., Higher School, 1984, p. 111-114).

 A method of producing a well-known pressed wood material includes the manufacture of wood particles by refining milled pre-steamed technological chips, drying the wood fiber thus made, applying a binder and other necessary additives to it, forming a wood carpet and pressing it hot.

 The disadvantages of the known pressed wood material and the method of its production are: the complexity of the process, high energy consumption due to the refiner method of grinding wood raw materials, requiring preliminary steaming, low quality wood boards, limiting their scope, high requirements for raw materials.

 Known pressed wood material, including layers of large wood particles in the form of shavings, interconnected by a binder (Annotated index of scientific and technological developments proposed for implementation, VNIIDREV, Balabanovo, 1990, p. 8 - prototype).

 A method of obtaining a well-known pressed wood material (particleboard with outer layers of large-sized chips) includes cleaning wood from impurities, debarking, making chips of a given size from it using chip machines, sorting chips into fractions, drying the resulting wood chips, applying a binder to them, forming wood carpet from the outer layers made of large-sized chips and the inner layer of a fine fraction of chips, and hot pressing of the wood carpet. It should be noted that when forming a wood carpet, wood particles of the same length are used in each layer (ZIMPELKAMP, DE, a leading company in the production of chipboards using oriented large-sized wood chips, uses chips with a length of 75-80 mm, attempts are made to use large-sized shavings 150-300 mm long).

 The disadvantages of the known pressed wood material and the method of its production are: high demands on the quality of the raw wood raw materials, high costs due to the complex process of manufacturing wood particles and the energy consumption of debarking processes, which require preliminary steaming of the raw materials, and grinding, low quality wood boards (i.e. h. the surface of the plates), limiting the scope of their application.

 The purpose of the invention is the use of low-grade wood raw materials (logging waste, sawmill waste, etc.), simplifying the process, reducing production costs, improving the quality of the manufactured material, expanding the range of manufactured plates and their scope, especially in building structures (in t .h beams).

 This goal is achieved by the fact that in the pressed wood material, including layers of large-sized wood particles interconnected by a binder, coarse fiber wood elements of arbitrary lengths are used as large-sized wood particles, each of the layers made of large-sized wood particles contains simultaneously enlarged fibrous wood elements of different lengths; the enlarged fibrous wood elements can be arranged in one or more directions, while in addition to layers made of large wood particles, it can simultaneously contain layers made of small wood particles or other materials, and the layers can alternate in any order, and in a method of manufacturing a pressed wood material containing layers of large-sized wood particles, including the manufacture of large-sized wood particles, drying the resulting wood astits, applying binder to the wood particles, the formation of the mat and pressing, manufacturing of large-sized wood particles operate by disrupting bonds between the fibers by mechanical deformation of the wood raw material in the transverse direction, and its subsequent disassembly at the aggregated fibrous wood elements on the boundaries destroyed linkages.

The claimed technical solution has the following differences from the prototype:
- coarse fiber wood elements of arbitrary lengths were used as large-sized wood particles;
- each of the layers made of large-sized wood particles contains simultaneously enlarged fibrous wood elements of different lengths;
- enlarged fibrous wood elements can be arranged with orientation in one or more directions;
- in addition to layers made of large wood particles, the pressed wood material may simultaneously contain layers made of small wood particles or other materials, while the layers can alternate in any order;
- the manufacture of large-sized wood particles is performed by breaking the bonds between the fibers by mechanically deforming the wood raw materials in the transverse direction and then disassembling them into enlarged fibrous wood elements along the boundaries of the broken bonds.

 In the patent information fund we reviewed, no similar technical solutions, as well as technical solutions with the indicated differences, were found.

 The claimed technical solution is applicable and will be implemented at industry enterprises in 1998-1999.

In FIG. 1 shows a single-layer pressed wood material with a random arrangement of coarse fiber wood elements, general view;
in FIG. 2 - three-layer pressed wood material with an oriented arrangement of enlarged fibrous wood elements in each of the layers, general view;
in FIG. 3 - the same, layer A, top view;
in FIG. 4 - the same, layer B, top view;
in FIG. 5 - same, layer C, top view;
in FIG. 6 - the same, enlarged fibrous wood elements.

 Pressed wood material 1 (wood-based panel) contains layers A, B and C of interconnected by binder large-sized wood particles 2 in the form of coarse fiber wood elements 3 of arbitrary lengths. The enlarged fibrous wood elements 3 are groups of fibers that have remained intact as a result of mechanical deformation of wood raw materials, and therefore have different thicknesses, widths, and their lengths are also different, their maximum length corresponding to the length of the processed wood raw materials.

 The material was prepared as follows.

 Example 1. Wood raw materials (long wood waste, lump waste, waste from woodworking machines, stems of annual plants, etc.) were subjected to mechanical deformation in the transverse direction, i.e. perpendicular to the direction of wood fibers, for example, by rolling between rolls, or constrained impact in mechanisms of impact. At the same time, there was a breakdown of bonds between fibers, fiber groups of wood raw materials. Then, the wood raw material thus treated was disassembled into fibrous wood elements 3 along the boundaries of the broken bonds.

The resulting wood particles 2 were enlarged wood fiber elements 3, combining fiber groups, the thickness and width of these elements depending on the number of fibers that entered them, and the length of each element was also different, because depended on how the interfaces between the groups of fibers passed during mechanical deformation of the raw material, and the maximum length corresponded to the length of the processed wood raw material. The enlarged fibrous wood elements 3 did not require further cutting, except for those whose length exceeded the overall dimensions of the pressed wood carpet. Next, the enlarged fibrous wood elements were dried to a moisture content of 2-3%, a urea-formaldehyde binder (for example, 9-12% with respect to the material) was applied to them and a wood carpet was formed, placing the enlarged fibrous wood elements randomly. By hot pressing the formed wood carpet at 150-170 ^° C. and 3.5 MPa, a single-layer wood board was obtained.

 Example 2. Pressed wood material 1 was prepared according to example 1, and a three-layer carpet was formed from layers A, B and C. Layers A and C contained longitudinally oriented enlarged fibrous wood elements 3 (i.e., along the pressed wood product), and the layer B contained coarse fiber wood elements 3 oriented transversely to the pressed wood product.

 It should be noted that in the implementation of the examples all kinds of low-grade wood raw materials of various sizes were used, which expanded the raw material base and allowed the use of low-quality raw materials, the exclusion of the cutting process in the manufacture of wood particles reduced the energy intensity of the grinding process and excluded the energy-intensive operation of debarking raw materials, the use of large-sized in each layer particles of coarse wood fibrous elements simultaneously of different lengths eliminated the operation of sorting into fractions and simplified perazim mat forming process and in general as well as possible to obtain a more robust material by the use of large-sized wood particles greater lengths than in the prior art, and improve the bonding of wood particles resinification different lengths among themselves (see. Table).

 The applicant carried out experiments on the manufacture of plates, in which, in addition to layers made of large wood particles, layers made of small wood particles or other materials were contained, while both layers could be located in any part of the plates made, depending on the required parameters plates. This allowed us to expand the range of plates and their scope.

 Thus, the invention allows the manufacture of pressed wood boards having improved physical and mechanical properties, which allowed to expand the scope of their application, expand the raw material base by using various wood raw materials, while maintaining better raw materials for other industries (for example, for the manufacture of plywood lumber and etc.), reduce production costs by simplifying the process, including at the stage of manufacturing wood particles, as well as reduce the energy intensity of cessa.

Claims (4)

 1. Pressed wood material, including layers, including those made of large-sized wood particles interconnected by a binder, characterized in that the elements in the form of fiber groups are used as wood particles, and the fibers in the groups have different thickness, width and length , and their maximum length corresponds to the length of the processed wood raw materials.  2. The pressed material according to claim 1, characterized in that the wood elements can be arranged with orientation in one or more directions.  3. The pressed material according to claims 1 and 2, characterized in that in addition to layers made of large wood particles, it can simultaneously contain layers made of small wood particles or other materials, while the layers can alternate in any order.  4. A method of manufacturing a pressed wood material containing layers, including those made of large-sized wood particles, comprising manufacturing large-sized wood particles, drying the obtained wood particles, applying a binder to the wood particles, forming a carpet and pressing it, characterized in that the manufacture of large-sized wood particles are performed by breaking the bonds between the fibers by mechanical deformation of wood raw materials in the transverse direction and its subsequent disassembly n and enlarged fibrous wood elements along the boundaries of broken bonds.

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