Plywood purchase
Plywood is a laminate of criss-cross plates of multilayer veneers. The outermost front panel is called the panel, and the opposite is called the backplane. The inner plate is called a core plate. In order to eliminate the anisotropy of wood and increase the strength, it is necessary to observe the following when manufacturing plywood: First, the principle of symmetry, the thickness of the veneer in the symmetrical layer, the species of tree, the moisture content, the grain direction, and the manufacturing method are all the same so that various internal stresses can be achieved. balance. The second is the principle of odd numbers. There are three plywood, five plywood and seven, nine, eleven plywood and so on.
Classification of plywood
One type of plywood is a weather resistant, boiling water resistant plywood, and thus has the advantages of durability, high temperature resistance, and steam handling.
The second type plywood is a water-resistant plywood that can be impregnated in cold water and impregnated with hot water for a short time.
The three types of plywood are moisture-resistant plywood, which can be impregnated in cold water for a short time and is suitable for use at room temperature. Used for furniture and general construction purposes.
The four types of plywood are non-moisture-resistant plywood, which are used under indoor normal conditions. The general-purpose plywood materials include beech, eucalyptus, ash, birch, eucalyptus, and poplar.
Plywood purchase notes:
1. Pick wood grain. When purchasing multiple pieces of plywood, plywood with a wood grain and similar color should be selected.
2. There must be no dead festival or patches on the front;
3. The number of horny joints (live joints) is less than 5, and the area is less than 15 mm2;
4. There is no obvious discoloration and color difference; there is no dense hairline cracking phenomenon and cracks exceeding 200 mm × 0.5 mm;
5. Less than 5 holes with diameter less than 2mm;
6. Resin vesicles with a length of 15 mm and less than 4 black squashes per square metre; Resin drips with a length of l50 mm and a width of 10 mm are less than 4 per square metre;
7. No decay or deterioration.
Fiberboard purchase
Fiberboard is made of wood or vegetable fiber as the main raw material, mechanically separated into monomer fibers, added with additives to form slabs, and then combined into artificial boards by hot pressing or adhesives. The thickness is mainly 3, 4 and 5 mm. Since the fiberboard has been treated with water repellent, its hygroscopicity is smaller than that of wood, and its shape stability and antibacterial property are all better.
Fiberboard classification
1. Classified by raw materials: wood fiberboard, non-wood fiberboard.
2. According to treatment methods: special hard fiberboard, ordinary hard fiberboard.
3. According to the weight density classification: hard fiberboard (also known as high-density fiberboard), semi-hard fiberboard (also known as medium-density fiberboard), soft fiberboard (also known as low-density fiberboard).
Fibreboard purchase considerations:
1. Even thickness, smooth and smooth surface, no stains, water stains, or adhesive marks. The surface of the board is fine, strong, and free from burrs.
2. Low moisture content and low moisture absorption.
3. Can strike the board surface by hand, the sound is crisp and sweet, and the quality of the even fiber board is better. If the sound is boring, you may have problems with loose glue.
Blockboard (large core board) purchase
Blockboards are made of small wooden strips of varying lengths and are made up of two or more layers of plywood or other decorative panels, which are then pressed. The core board is commonly used for pine, cassia, eucalyptus, eucalyptus and other wood.
Blockboard purchase notes:
1. Blockboard is divided into one, two, three and so on. Directly decorated panels, should use a first board, only as a floor with the third-class board available.
2. Pick a board with a smooth surface, a few knots, and a few clips.
3. Check the veneer quality and density of the core board from the side or sawed section.
4. One side of the big core board must be a whole board, and only one seam is allowed on the other side. In addition, the surface of the large core board must be dry and clean.
5. When selecting the blockboard, be sure to select the machine's puzzle and do not use hand-made puzzles.
6. Observe whether there is any glue and putty phenomenon around it.
7. Sharply tap the surface of the device to hear if there is a big difference in the sound, if there is a change in the sound, there is a hollow inside.
8. When purchasing in bulk, check the quality inspection documents and quality inspection certificates.
Panel purchase furniture