What is particle board?
Particle board, also known as chipboard, is a type of artificial board that cuts various branches, small diameter wood, fast-growing wood, sawdust, etc. into fragments of a certain size, dries them, mixes them with adhesive, and presses them under a certain temperature and pressure, resulting in uneven particle arrangement. Although particle is not the same type of board as solid wood particle board. Solid wood particle board is similar in processing technology to particleboard, but its quality is much higher than particle board.
The production methods of particle board are divided into intermittent production of flat pressing method, continuous production of extrusion method, and rolling method according to their different blank forming and hot pressing process equipment. In actual production, the flat pressing method is mainly used. Hot pressing is a critical process in the production of particle board, which solidifies the adhesive in the slab and solidifies the loose slab into a specified thickness after being pressurized
The process requirements are:
1.）Appropriate moisture content. When the surface moisture content is 18-20%, it is beneficial to improve the bending strength, tensile strength, and surface smoothness, reducing the possibility of blistering and delamination during unloading of the slab. The moisture content of the core layer should be appropriately lower than the surface layer to maintain appropriate plane tensile strength.
2.)Appropriate hot pressing pressure. Pressure can affect the contact area between particles, the thickness deviation of the board, and the degree of adhesive transfer between particles. According to the different density requirements of the product, the hot pressing pressure is generally 1.2-1.4 MPa
3.）Appropriate temperature. Excessive temperature not only causes the decomposition of urea formaldehyde resin, but also causes local early solidification of the slab during heating, resulting in waste products
4.）Appropriate pressurization time. If the time is too short, the middle layer resin cannot fully cure, and the elastic recovery of the finished product in the thickness direction increases, resulting in a significant decrease in plane tensile strength. The hot pressed particleboard should undergo a period of moisture adjustment treatment to achieve a balanced moisture content, and then be sawn, sanded, and inspected for packaging.
According to the structure of particle board, it can be divided into: single-layer structure particle board; Three layer structure particle board; Melamine particle board, oriented particle board;
Single layer particle board is composed of wood particles of the same size pressed together. It is a flat and dense board that can be veneered or laminated with plastic, but not painted. This is a waterproof particle board, but it is not waterproof. Single layer particle board is suitable for indoor applications.
The three-layer particle board is made of a layer of large wood particles sandwiched between two layers, and is made of very small high-density wood particles. The outer layer has more resin than the inner layer. The smooth surface of three-layer particleboard is very suitable for veneering.
Melamine particle board is a decorative paper soaked in melamine that is fixed to the surface of the particleboard under high temperature and pressure. Melamine particle board has waterproof properties and scratch resistance. There are various colors and textures, and the applications of melamine particle board include wall panels, furniture, wardrobes, kitchens, etc
According to surface condition:
1. Unfinished particle board: sanded particleboard; Unsanded particleboard.
2. Decorative particle board: Impregnated paper veneer particle board; Decorative laminated veneer particle board; Single board veneer particle board; Surface coated particle board; PVC veneer particleboard, etc
Advantages of particle board:
A. Has good sound absorption and insulation performance; Particle board insulation and sound absorption;
B. The interior is a granular structure with intersecting and staggered structures, and the performance in all directions is basically the same, but the lateral bearing capacity is relatively poor;
C. The surface of the particle board is flat and can be used for various veneers;
D. During the production process of particleboard, the amount of adhesive used is relatively small, and the environmental protection coefficient is relatively high.
Disadvantages of Particle Board
A. The internal structure is granular, making it difficult to mill;
B. During cutting, it is easy to cause tooth breakage, so some processes require high processing equipment requirements; Not suitable for on-site production;
How to distinguish the quality of particleboard?
1. From the appearance, it can be seen that the size and shape of the sawdust particles in the center of the cross-section are large, and the length is generally 5-10MM. If it is too long, the structure is loose, and if it is too short, the deformation resistance is poor, and the so-called static bending strength is not up to standard;
2. The moisture-proof performance of artificial boards depends on their density and moisture-proof agent. Soaking them in water for moisture-proof performance is no good. Moisture-proof refers to moisture resistance, not waterproofing. Therefore, in future use, it is necessary to distinguish between them. In northern regions, including North China, Northwest, and Northeast China, the moisture content of boards should generally be controlled at 8-10%; The southern region, including coastal areas, should be controlled between 9-14%, otherwise the board is prone to moisture absorption and deformation.
3. From the perspective of surface flatness and smoothness, it is generally necessary to pass through a sandpaper polishing process of around 200 mesh when leaving the factory. Generally, finer points are better, but in some cases, such as sticking fireproof boards, they are too fine to be easily glued.
Application of particle board:
1. Particle board is used as a protective material for hardwood flooring to protect the hardwood board from injury,
2. Particle board is commonly used to manufacture cores and flush doors in solid cores. Particle board is a good door core material because it has a smooth and flat surface, easy to bond with the door skin, and good screw fixation ability, used to fix hinges.
3. Particle board is used to make false ceilings because it has good insulation effect.
4. Particle board is used to make various furniture, such as dressing tables, tabletops, cabinets, wardrobes, bookshelves, shoe racks, etc.
5. The speaker is made of particle board because it can absorb sound. This is also why particle boards are used for the walls and floors of recording rooms, auditoriums, and media rooms.
Post time: Aug-28-2023