Plywood classification

Plywood is divided into ordinary plywood (suitable for a wide range of plywood) and special plywood (for plywood for special purposes).

The quality requirements of plywood include appearance grade, specification size and physical and mechanical properties.

The three tests of appearance grade, specification size and physical and mechanical properties are all qualified to judge that the product is a qualified product, otherwise it is judged to be unqualified. Plywood shall have the product quality appraisal certificate of the quality inspection department of the manufacturer when leaving the factory, indicating the type, specification, grade, bonding strength and moisture content of the plywood.

(1) Specifications of ordinary plywood The thickness of plywood is 2.7mm, 3.3mm, 4.5mm, 5.5mm, 6mm... from 6mm, increasing by lmm. The thickness is from 4 mm or less to thin plywood. 3mm, 3.5mm, 4mm thick plywood is a common specification. Other thickness plywood shall be produced after agreement between the supplier and the buyer.

(2) Appearance grade Ordinary plywood is divided into four grades according to the material defects and processing defects visible on the plywood after processing: special grade, first grade, second grade, third grade, etc., among which, the first grade, the second grade and the third grade are the main grades of ordinary plywood. .

The above four grades of panels should be sanded (scratched), and those with special needs may not sand (scrape) light or double-faced sand (scraping) light. Sanding plywood refers to plywood that is sanded (or scraped) by a sander (or scraper). The grade is generally determined by visual inspection of the allowable defects on the plywood. The grade depends on the allowed material defects, processing defects, and the requirements for splicing.

What are the advantages and disadvantages of splint? How to choose?

The splint, also known as plywood, is a planed piece of wood that is sliced to a thickness of about 1 mm per layer. After fully air-dried, add glue, compact it by special mechanical equipment, and then affix the surface layer with decorative texture and material on both sides, and cut into a certain specification of decorative sheet. The most commonly used splint size for decoration is 1220 mm x 2440 mm.

The hardness of the splint is generally high. Since the material and texture are vertically staggered during the gluing process, the strength is large and the deformation is not easy.

According to the number of layers, the splint can be divided into three types: three plywood, five plywood, nine plywood, twelve plywood, eighteen plywood and many other varieties. The most commonly used decoration is three plywood and five plywood, which is commonly known as plywood. And plywood. The more layers of the splint, the greater the thickness, the higher the strength, the stronger the bearing capacity, and the less likely to bend. The splint is mostly used in the high-grade decorative base structure. It is suitable for installing and fixing decorative parts with large load.

Of course, the splint also has its own shortcomings, that is, the general cost is higher; if the material is not sufficiently dry or the production process has problems, the external force is difficult to adjust when the sheet is deformed; in addition, the splint is not as smooth as the MDF surface layer, and the splint is used as the base layer. When the surface of the fireproof board, aluminum-plastic board and other decorative sheets are bonded, the medium-density board is not as strong as the base layer.

It is not difficult to pick a splint, but consider it in the following directions:

1. Pay attention to the quality of the panel. The large amount of decoration in the market is imported Liuqi three plywood. Imported from Indonesia is called "printing board". Imported from Malaysia is called "horse board". The quality of the "printing board" is better than that of the "horse board", and the price is also two or three yuan per piece. When choosing, be sure to pay attention to whether the panel is willow wood or other hard wood. In contrast, Liu Yan noodles are better. And it is best to use imported willow veneer.

2. Pay attention to the inner sandwich material. Generally, the inner layer of the splint is mostly miscellaneous wood. It is best to use high-quality materials such as willow, and pay attention to whether the cross-section is smooth, whether the rubber is foamed or foamed between the lamellar layers, and whether the core plate has a large gap.

3. Pay attention to how the whole board looks. The plywood of good quality has no warpage, deformation and cracking. The edges are straight, the wall thickness is full, and the dimensions are standard. The surface has the same color, no scars, joints, spots, wormholes, bruises, stains, defects and repairs.

4. Pay attention to the level. At present, the import of the willow wood plywood is mainly BB, CC grade, AA grade is rare. Be wary that some operators pretend to be import plates with a better quality joint venture board, or pretend to be high-grade at a low level. In fact, as long as you look at the outer packaging, you can identify it. Generally imported plywood is printed on the outer packaging with the import mark, which is marked with English import origin: Indonesfa (Indonesia), Malaysia (Malaysia) and so on.