The method of obtaining chipboard

 

(57) Abstract:

Usage: the invention relates to the production of chipboard on the basis of particles of wood, characterized by reduced emission of harmful and toxic substances. The invention can be used in the manufacture of chipboard and fibre materials used in the furniture and construction industries. The invention is: to reduce the consumption of binders and toxicity chipboard proposes a method of receiving plates containing 20-80% less binders. The implementation of the invention is achieved by the fact that in the three-layer plate outer layers are made of non-hydrolyzed wood particles, and the middle layer of wood particles treated with steam under pressure. In the manufacture of plates, according to the invention only on non-hydrolyzed wood particles additionally applied urea-formaldehyde resin. The inner layer plate are formed from wood pulp obtained by treatment of the wood with steam at a temperature of 170-230C and containing free sugars in an amount not less than 5% when the content of the hydrolyzed wood particles in the carpet from 20 to 80 wt.%. enjoy high physical-mechanical indicators. table 2.

The invention relates to the production of chipboard-based particles of the wood plates differ in low emission of harmful and toxic substances.

The invention can be used in the manufacture of chipboard and fibre materials used in the furniture and construction industries.

Wood-layered plate, as a rule, consist of two main parts: wood filler and a polymeric binder. As polymeric binders used synthetic thermosetting resins prepared from phenols, urea, formaldehyde.

The drawback of such materials is that they are toxic to humans: during manufacturing and during operation of the finished products, vapours phenol, formaldehyde, ammonia, providing irritant effect on skin and mucous membranes. Moreover, a polymeric binder, prepared on the basis of urea-formaldehyde resins, roads and have a significant impact on the cost of finished plates.

A known method of manufacturing particleboard (USSR author's certificate N 1247292, MKI4B 27 N 3/06, 04.11.1983), when bonded to the us to reduce the consumption of binder in the manufacture of chipboard, however, it is suitable only for the manufacture of chipboard, coated with a polymer film, has high complexity associated with flooring adhesive silicone paper.

Known technical solutions closest to destination and technical nature of the claimed object is a method of production of composite materials from lignocellulosic raw materials (patent RU N 2075384 from 20.03.97, MKI6B 27 K 9/00), composed of cellulose, lignin, hemicellulose and contains large quantities of free sugars derived from carbohydrate portion of plant material when it is steaming. The composite material produced by hot pressing the hydrolyzed pulp without the use of synthetic binders.

The method eliminates the use of synthetic binders and make plates from different lignocellulosic materials. However, the disadvantages of the described method include low physical and mechanical properties of the obtained plates.

The purpose of the invention to provide a non-toxic chipboard with high physical-mechanical indicators.

The invention of Zama plate contains 20-80% less binders, which leads to the reduction of its cost and toxicity, while finished products have high strength characteristics.

The implementation of the invention is achieved in that part of the press composition consisting of wood particles coated with urea-formaldehyde binder is replaced by steamed wood material containing no urea-formaldehyde resin. When forming a carpet of three layers, according to the invention, the outer layers of the Mat are made of non-hydrolyzed wood particles coated on their surface with a urea-formaldehyde resin, and the middle layer of the Mat formed from hydrolyzed lignocellulosic material is treated with steam at a temperature of 170-230oC and dried to a moisture content of 5%.

It is claimed the qualitative and quantitative composition, the formation of the three-layer carpet with a middle layer of hydrolyzed wood particles, provide plates of high strength and hydrophobic properties, low cost and toxicity of finished products.

The outer layers of the plate, according to the invention, made of non-hydrolyzed wood chips, which is applied to karbamidoformaldegidnye resin (8-9%). Mass doinig particles, containing free sugars in an amount not less than 5%, and has high adhesion to the wood particles of the outer layer. Free sugars (reducing agents) are formed in the wood mass as a result of hydrolysis easy-hydrolyzed part of the hemicellulose under the action of water molecules and high temperature. Mass fraction of the inner layer is from 20 to 80% of the entire plate. This ratio provides the opportunity to receive Board materials with the highest strength and hydrophobic properties.

The proposed invention is implemented as follows.

In a known manner to receive wood chips, process it with a solution of urea-formaldehyde resin (8-9% resin by weight dry chips), dried to the desired moisture and form a first layer of carpet.

Wood chips (sawdust, chips) process in barotermicheskoi chamber with water vapor at a temperature of 170-230oC for 1-15 min with subsequent decompression for 0.5-1 C. the Obtained wood pulp is dried to a moisture content of 5%. Dried gidralizovanny wood pulp is applied to the first layer of the carpet.

Next, on the layer of the hydrolyzed pulp put a layer of wood chips, obrabotala outer layer.

Molded carpet is subjected to cold pressing and served on a hot press, where they perform hot pressing at a known temperature and pressure.

An example of wood-laminated plate according to the invention.

Wood chips birch in the amount of 500 g of steamed at a temperature of 190oC under a pressure of 1.25 MPa. After 15 min after the start of the processing performed decompression of the reactor and the resulting wood pulp and dried to a moisture content of 5%.

On non-hydrolyzed wood chips (460 g) put a solution of urea-formaldehyde resin (resin flow 8-9%). The resulting material is dried to a moisture content of 8-10%, and divide into 2 parts. One part pitched chip (weight 250 g ) form the bottom layer of the slab (sample area 300 mm x 300 mm). On the bottom layer put dried gidralizovanny steam wood chips (weight 500 g), which is the inner layer of the carpet. This layer is applied a second part pitched chip (weight 250 g)

The formed carpet podpisovat with a specific pressure of 2 MPa and then spend hot pressing at a temperature of 160-170oC, and a specific pressure of 3.3 MPa duration of 1 min per 1 mm of the finished plate. After the end is analyzed according to GOST 10632-89, the data presented in table. 1 (example 4).

In table. 1 shows examples of making multilayer chipboard using different quantities of lignocellulosic material is treated with steam at elevated temperature and containing free sugars according to the invention, indicating the conditions of handling and compaction and physico-mechanical properties of the obtained materials.

In table. 2 shows examples of making a press-compositions containing 50% of the inner layer consisting of wood pulp treated with steam at various temperatures and physico-mechanical properties of the obtained plate.

The method of obtaining chipboard, including milling of lignocellulosic raw materials, forming a carpet of 3 layers, the outer layers of which are made of wood particles, and the medium of wood particles, steamed, hot pressing and holding the press under pressure, characterized in that the outer layers of the wood particles is additionally applied urea-formaldehyde resin, and when forming the middle layer using wood particles treated with steam at 170 - 230oC and containing free sugars in the number who

 

Same patents:

The invention relates to woodworking industry, in particular the production of Board materials, and can be used in the manufacture of combustible materials

The invention relates to chemical technology, in particular to the field of plastics

The invention relates to the woodworking industry and can be used in the manufacture of low pressings from wood and/or vegetable particles

The invention relates to the production of wood pressing mass-based particles of vegetable origin, in particular to press composition, its preparation and method of production of composite materials based on it

The invention relates to the production of building materials and can be used in the production of wall profile pressed blocks of wood waste

The invention relates to compositions for the manufacture of chipboard

The invention relates to woodworking industry, in particular the production of Board materials, and can be used in the manufacture of combustible materials

The invention relates to the chemical industry and can be used in the production of low-toxic materials, for example in the production of low-emission wood-based panels

The invention relates to building materials and can be used in the manufacture of heat-insulating material

The invention relates to the manufacture of articles intended for use in friction mechanisms vehicles, brake nodes anchoring and mooring arrangements floating funds, other industries

The invention relates to the production of wood pressing mass-based particles of vegetable origin, in particular to press composition, its preparation and method of production of composite materials based on it

The invention relates to the continuous production of cardboard by a dry process using as raw material lignocellulosic material such as wood, straw, sugar cane etc

The invention relates to woodworking, and more particularly to equipment for the manufacture of hardboard, particle Board or other, made from plant or wood materials, wood panels or similar materials, and can also be used for heat treatment and conditioning of other materials, such as plywood or wood veneer

The invention relates to the timber and woodworking industry, in particular to the production of organic fibrous materials

The invention relates to woodworking industry, in particular the production of Board materials, and can be used in the manufacture of combustible materials

The invention relates to methods for composite materials

The invention relates to woodworking industry and can be used in the manufacture of pressed wood materials, such as wood boards

The invention relates to the manufacture of composite materials of organic fillers of natural origin

The invention relates to the production of compositions prepared from the crushed plant material, mainly from wood waste, mineral binders and can be used for construction of a wood-composite materials by the pressing of the raw material mixtures

The invention relates to the production of compositions prepared from the crushed plant material, mainly from wood waste, mineral binders, and can be used for production of heat and sound insulation of wood-composite materials by the pressing of the raw material mixtures

The invention relates to measuring technique and can be used in devices for quality control of the surface of wood materials, in particular wood-based panels, as well as specialized products
Up!