What is the production process of the finger joint board?

The so-called finger joint plate refers to the splicing of multiple pieces of wood, and the upper and lower sides no longer stick to the splint. Because the vertical wooden board adopts a zigzag interface, which is similar to the cross-docking of two fingers, it is called the finger joint board, which is widely used in the modern furniture industry. A kind of decorative sheet product, which not only has a delicate texture, clear wood grain, but also has certain pressure resistance; the high quality finger joint board is more related to the type of wood it takes, and to a greater extent its production process. What is the production process of the finger joint board? See how Xiaobian explains it for you!

Finger joint plate production process: cutting raw materials

Cutting the wood into units of different shapes and recombining them into various sheets in a certain way can improve certain properties of the wood, such as anisotropy, heterogeneity, swelling and shrinkage. The plate composed of large units has higher mechanical strength, and the plate composed of small units has better homogeneity. Precise control of the thickness error of the rotary cutting veneer can increase the yield of 2 to 3%. The cut wood shavings affect the overall physical and mechanical properties of the particleboard; the fiber morphology is also closely related to the strength of the fiberboard. The final sawing, grinding, etc. of the sheet also affect the quality of the product.

Finger joint plate production process: dry sheet

Drying processes include veneer drying, shaving drying, fiber drying in dry fiberboard processes, and heat treatment of wet fiberboard. Drying process and process control are different from finished drying. The process control of the drying of the material is based on the relative humidity of the drying medium, and care must be taken to prevent the generation of drying stress. The drying of the sheet-like and granular materials used for the wood-based panel is carried out under relatively high temperature, high speed and continuous conditions. At the end of the phase, it is immediately transferred to the deceleration and drying phase. The materials such as veneers and shavings are thin, the surface area is large, and the influence of dry stress is little or no; in addition, the dry heat source is mostly steam or combustion gas. Infrared drying energy consumption is too large, 5500 ~ 18000 kJ per evaporation of 1 kg of water; and steam drying only 4200 ~ 5000 kJ. The advantage of high-frequency drying is that the drying rate of the dry material is high and the final moisture content is uniform, but the drying cost is too high.

Finger joint board production process: sizing

Includes veneer coating, shavings and fiber sizing. Veneer gluing still uses traditional roller gluing in Europe. Since the 1970s, many plywood factories have switched to laminating. Chinese plywood factories also use roller coating. The leaching method is suitable for the process of sizing the intermediate plate and the automated slab. Shavings and fiber sizing are now mainly used by spray glue.

Finger-joint production process: forming and molding of pressure-bonded plywood

The slab forming and pressurization of particleboard fiberboard is a molding process for the manufacture of wood-based panels. The study of wood structure by wood science reveals that the arrangement of wood fibers in natural wood is hierarchical and directional, and thus can withstand a certain amount of external force exerted by nature on wood. The evolution of the manufacturing process of wood-based panels is undoubtedly affected by this understanding: the slab level of particleboard and fiberboard is changed from a single layer to a three-layer structure and a multi-layer structure; the arrangement of shavings and fibers in the slab also tends to be oriented from a random type; The orientation of the adjacent layers of the plywood fibers perpendicular to each other improves the anisotropy of the wood under natural growth conditions and improves dimensional stability.

Finger joint plate production process: post-production processing

After the final processed sheet is discharged from the hot press, it is subjected to the stage of cooling and moisture content balance, that is, sawing and sanding, and the hard fiber board is subjected to heat treatment and humidity control. In the past, the sawing edges of the plates were cold sawing. Now, the hot sawing method is also used, but the hot sanding method must not be used. The hot sand will damage the surface quality of the finished product. According to the requirements of use, some plates need special treatment such as dipping, painting, laminating and edge sealing.