Plywood purchase
The plywood is made of a plurality of veneers which are criss-crossed in a crisscross pattern. The outermost front panel is called the panel, and the reverse side is called the back panel. The inner layer is called the core board. In order to eliminate the shortcomings of wood anisotropy and increase the strength, the following should be observed when making plywood: First, the principle of symmetry, the thickness of the single layer of the symmetrical layer, the tree species, the water content, the direction of the wood grain, and the manufacturing method are the same, so as to make various internal stresses. balance. The second is the odd number principle. There are plywood, plywood and seven, nine, eleven plywood and so on.
Classification of plywood
One type of plywood is weather-resistant and boiling-resistant plywood, and thus has the advantages of durability, high temperature resistance and steam treatment.
The second type of plywood is a water resistant plywood that can be immersed in cold water and impregnated with hot water for a short time.
The three types of plywood are moisture-resistant plywood, which can be dipped in cold water for a short time and is suitable for indoor use at room temperature. Used for furniture and general construction purposes.
The four types of plywood are non-durable plywood and are used under normal indoor conditions. The general purpose plywood is made of beech, eucalyptus, ash, birch, elm, and poplar.
Plywood purchase notes:
Pick wood grain. When purchasing multiple plywood, you should choose wood grain, similar color plywood.
There must be no dead knots and patches on the front;
The number of horny joints (live joints) is less than 5, and the area is less than 15 square millimeters;
No obvious discoloration and chromatic aberration; no dense hairline cracking and cracks exceeding 200 mm × 0.5 mm;
Less than 5 holes with a diameter of less than 2 mm;
Resin pouches with a length of 15 mm, black ash skin less than 4 per square meter; resin leaking at a length of l50 mm and a width of 10 mm less than 4 per square meter;
No decay and deterioration.
Fiberboard purchase
The fiberboard is made of wood or vegetable fiber as the main raw material, mechanically separated into monomer fibers, added with additives to make slabs, and combined into a wood-based panel by hot pressing or adhesive. The thickness is mainly 3, 4, 5 mm. Due to the waterproof treatment, the fiberboard is less hygroscopic than wood, and has good shape stability and antibacterial properties.
Classification of fiberboard
1. Classified by raw material: wood fiberboard, non-wood fiberboard.
2. Classified by treatment: special hard fiberboard, ordinary hardboard.
3. Classified by volume: hard fiberboard (also known as high-density fiberboard), semi-hardboard (also known as medium-density fiberboard), softboard (also known as low-density fiberboard).
Fiberboard purchase considerations:
The thickness is even, the surface is smooth and smooth, and there are no stains, water stains or sticking. The surrounding panels are fine, strong and have no burrs.
Low moisture content and low hygroscopicity.
The surface of the board can be tapped by hand, the sound is crisp and pleasant, and the uniform fiberboard quality is good. If the sound is boring, there may be a problem with the glue.
Blockboard (large core board) purchase
The blockboard is made of small wooden strips of different lengths and is combined with a single layer of two or two layers of plywood or other veneers, and then pressed. The core board is usually made of pine, ash, eucalyptus, eucalyptus and the like.
Blockboard purchase notes:
1. Blockboard is divided into one, two, three, etc. For direct use as a veneer, a first-class board should be used, which can only be used as a third-class board for the backplane.
2. Pick a plate with a smooth surface, no knots, and few skins.
3. Check the thin wood quality and compactness of the core from the side or the profile after sawing.
4. One side of the large core board must be a whole piece of wood, 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, you must choose the machine board, do not use the hand board.
6. Observe whether there is any glue or greasy putty around it.
7. The sharp-mouthed instrument carefully hits the surface to hear if there is a big difference in its sound. If the sound changes, there will be a hollow inside.
8. When purchasing in large quantities, check the quality report such as the test report and quality inspection certificate of the product.
Ningbo Yinzhou Hengxi Winbate Household Product Manufacturer , https://www.winbatehousehold.com