1, blockboard. Blockboard is a solid board consisting of a core board and a watch board. The core board of the fine wood board is spliced by wood planks. Generally, the same tree species or similar tree species are selected. The moisture content of the core board of blockboard is controlled between 6 and 12%, and the width of the core strip is not more than three times the thickness, and no large cracks or voids are allowed. There are two fine-grained wooden boards, the better quality is called the front panel, and the other side is the back panel. The table can be sanded on one side, sanded on both sides, or on both sides. In special cases, the surface of fine-grained boards allows for appropriate repairs. The technique of fine-grained wood board makes full use of the corner waste in wood processing. It is a construction board with large format, moderate thickness and uniform structure.
The surface of the blockboard should be flat, without warpage, deformation, blistering or depression; the core strips are arranged uniformly with small gaps, and the core strips are not decayed, broken, wormholes, knots, etc. Some blockboards cut corners and cut materials, and the gaps in the solid wood strips are large. If you nail in the gaps, there is basically no nail-holding force.
Consumers can look into the sun when choosing, and the gaps between the solid wood bars will be white. If the joinery strength of the blockboard is not good, there will be a “squeak” opening sound at the corner. If the large core board emits a fragrant wood odor, it means that the amount of formaldehyde is less; if the odor is pungent, it means that the formaldehyde is released more (natural logs also contain trace amounts of aldehyde-containing substances in the natural state).
The quality of blockboard is very different, so you should check it carefully when buying. First, check whether the core material is dense, whether there are obvious seams and decayed wood strips, and whether there are obvious seams and decayed wood strips. There may be worm eggs in the decayed wood strips, and insect worms are likely to occur in the future; The phenomenon of filling putty. This phenomenon is generally to make up for internal cracks or hollows. Then, tap the surface of the sheet with a sharp-tipped instrument and listen to whether there is a large difference in sound. If there is a change in the sound, it means that there are hollows in the sheet. These phenomena will weaken the overall bearing capacity of the board, and the long-term uneven force will distort and deform the board structure, affecting the appearance and use effect.
2. Multi-layer board. Multi-layer boards are sometimes called plywood. They are similar to fine-grained boards in terms of manufacturing methods and materials selection. Multi-layer boards and fine-grain boards are made of several layers of boards, but they are different from fine-grain boards. The point is that the multilayer board is not necessarily three layers, and each layer of the multilayer board has the same thickness. Multi-layer boards have good structural strength and good stability, and are mainly used for the production of wooden products such as the bottom plate of decorative panels and the back plate of panel furniture. Plywood is made of three or more layers of solid wood veneer or sheet glued by hot pressing. Commonly, there are three plywood, five plywood, nine plywood, and twelve plywood (commonly known as plywood, five centimeter, nine centimeter Twelve centimeter plate), good structural strength and good stability. Plywood has a large amount of glue, so it must be edge-sealed during construction to reduce pollution.
Plywood is mainly used for various wood products such as the bottom plate of decorative panels and the back plate of panel furniture. The choice of plywood mainly depends on its formaldehyde release and glue strength. If the plywood has poor bonding strength, it will easily fall apart. When choosing, pay attention to whether the nominal thickness of the plywood matches the actual thickness. Pay attention to the following points when selecting plywood:
① There is a difference between front and back of plywood. When selecting, the plywood should have clear wood grain, smooth and smooth front, not rough, and smooth and no stagnation.
② Plywood should be free from defects such as breakage, bumps, bruises, and scars.
Post time: Mar-09-2020