What are the classifications, uses and raw material processes of particle board? Particle board is a kind of board made of small pieces, fibers, particles or other shapes of fragments processed from wood or other non-wood plants, which are pressed under heat and pressure after applying adhesive. Particleboard can be classified differently according to its use, structure, manufacturing method and raw materials. The following article introduces in detail the classifications, uses and raw material processes of particle board.
Classification of particle board:
According to the use of particle board:
- Class A particleboard: suitable for furniture, building interior decoration and other fields.
- Class B particleboard: suitable for furniture, building interior decoration and other uses.
According to the structure of particle board:
- Single-layer particle board: Made of a layer of particles and a layer of adhesive.
- Three-layer particle board: Made of two layers of particles and a layer of adhesive in the middle.
- Gradient particle board: The size and density of the particles gradually change in the thickness direction of the board.
- Oriented particle board: The arrangement direction of the particles is consistent with the length direction of the board.
- Waffle particle board: Particleboard with a special surface shape.
- Molded particle board: Particleboard with a special shape and texture.
According to the manufacturing method of particle board:
- Flat pressed particleboard: pressed on a flat press.
- Extruded particleboard: pressed on an extruder.
According to the raw materials used in particle board:
- Wood particleboard: made of particles processed from wood.
- Bagasse particleboard: made of particles processed from bagasse.
- Flax chip particleboard: made of particles processed from flax chips.
- Cotton stalk particleboard: made of particles processed from cotton stalks.
- Bamboo particleboard: made of particles processed from bamboo.
- Cement particleboard: made of a mixture of cement and particles processed from wood or other non-wood plants.
- Gypsum particleboard: made of a mixture of gypsum and particles processed from wood or other non-wood plants.
According to the surface condition of particle board:
- Unfaced particleboard: The surface of the board has not been decorated and can be directly processed or used.
- Faced particleboard: The surface of the board has been decorated, such as veneer, spraying, printing, etc., with beautiful appearance and good wear resistance and pollution resistance.
- Impregnated paper veneer particleboard: With particleboard as the base material, the surface is covered with a layer of impregnated paper, and the impregnated paper is bonded to the base material through a hot pressing process to form a board with beautiful appearance and excellent performance.
According to the sanding effect of the particle board surface:
Sanded particle board; Unsanded particle board.
According to the veneer particle board:
Impregnated paper veneer particleboard; decorative laminate veneer particleboard; veneer particleboard; surface coated particleboard; PVC veneer particleboard, etc.
According to the product classification of particle board:
There are three types: low density (0.25-0.45 g/cm3), medium density (0.45-0.60 g/cm3), and high density (0.60-1.3 g/cm3), but the particleboards usually produced are those with a density of 0.60-0.70 g/cm3.
According to the structure of particle board:
there are three types of structures: single-layer, three-layer (including multi-layer), and gradient. According to water resistance, there are indoor water-resistant and outdoor water-resistant types. According to the arrangement of the particles in the slab, there are two types: directional and random. In addition, there are various particleboards made of non-wood materials such as cotton stalks, hemp stalks, bagasse, rice husks, etc., as well as cement wood fiber boards and cement particleboards made of inorganic adhesive materials.
What are the uses of particle board?
In the production of particleboard, due to the different production methods, types of raw materials, board structure and density, its performance varies greatly, and its uses are also different, but it is mainly used as furniture and construction materials. Due to its low cost and many better properties than finished materials, particleboard is more popular as a core material than wood. Particleboard can be used as furniture parts by veneer, thin wood, impregnated paper, decorative paper and other veneers. The edges and ends of the boards can be edge-sealed with wood strips or plastics, or post-formed edge-sealed. These particleboards can be used on various furniture parts after decorative treatment. It is used in construction such as floor materials, ceilings and wall panels, as well as interior decoration materials for kitchens and closets. In addition, particleboard can also be used in trains, cars, ships, interior decoration and packaging.
Particleboard is often used as a decorative board for interior walls in home or building decoration, which is often called partition wall. It usually needs to be covered with plastic veneer on the surface during use. Unveneered particleboard is often used as the base board of wallboard, which can only play a supporting role, while medium-density particleboard and high-density particleboard contain considerable glue, which can be used to make semi-finished building decorative panels that can be directly installed.
If you are worried that the sound insulation effect of the new house is not very good, you can install particleboard during decoration. Basically, if people who have installed particleboard are particularly satisfied with the sound insulation of their rooms, they don’t have to worry about affecting others and they will not be affected by noise.
Raw materials for particle board production
The raw materials for making particleboard include wood or wood fiber materials, adhesives and additives. The former accounts for more than 90% of the dry weight of the board. Wood raw materials are mostly taken from felled timber between forests, small-diameter timber (usually less than 8 cm in diameter), logging residues and wood processing residues. Wood chips, shavings, wood fibers, sawdust, etc. processed into flakes, strips, needles, and particles are called scraps. In addition, non-wood materials such as plant stems and seed shells can also be made into boards, and their names are often named after the materials used, such as hemp stalks (particleboards), bagasse (particleboards), etc. Urea-formaldehyde resin glue and phenolic resin glue are mostly used as adhesives. The former has a light color and a low curing temperature. It has a good gluing effect on particleboards made of various plant raw materials such as wheat straw and rice husks, and the hot pressing temperature is 195-210°C.
Particle board production process
The production method of particleboard is divided into intermittent flat pressing method and continuous extrusion method and roller pressing method according to the different slab forming and hot pressing process equipment. Flat pressing method is mainly used in actual production. Hot pressing is a key process in particleboard production. Its role is to solidify the glue in the slab and consolidate the loose slab into a board of specified thickness after pressurization. Its process requirements are:
- Appropriate moisture content. When the surface moisture content is 18-20%, it is conducive to the improvement of bending strength, tensile strength and surface finish, and reduces the possibility of blistering and delamination of the slab when unloading. The moisture content of the core layer should be appropriately lower than that of the surface layer to maintain appropriate plane tensile strength.
- Appropriate hot pressing pressure. Pressure can affect the contact area between shavings, the thickness deviation of the board and the degree of glue transfer between shavings. According to the different density requirements of the product, the hot pressing pressure is generally 1.2-1.4 MPa.
- Appropriate temperature. Too high temperature will not only decompose urea-formaldehyde resin, but also cause partial premature solidification of the slab when the temperature rises, resulting in waste.
- Appropriate pressing time. If the time is too short, the middle layer resin cannot be fully solidified, the elastic recovery of the finished product in the thickness direction will increase, and the plane tensile strength will be significantly reduced. The hot-pressed particleboard should be humidified for a period of time to make its moisture content reach a balanced state, and then sawed, sanded, inspected and packaged.
In terms of raw material technology, the main raw material for making particleboard is wood or other non-wood plant shavings, such as bagasse, flax shavings, cotton stalks, bamboo, etc. After these raw materials are crushed, dried, screened, glued, etc., they are pressed into boards under heat and pressure. In order to improve the performance of the board, some additives such as waterproofing agents and fire retardants can also be added. In addition, the moisture content of the raw materials, the amount of glue, the hot pressing temperature and time, etc. need to be controlled during the manufacturing process to ensure the quality and performance of the board.
The above is the introduction of the classification, uses and raw material processes of particle board in this article. I hope it can help you!