Blockboard, commonly known as big core board, is a board made of glued and hot pressed natural rotary cut veneers and solid wood panels. It is one of the main varieties of artificial board for decoration and fitment, featuring beautiful appearance, high strength, light weight and small deformation, and is mainly used in furniture manufacturing, doors and windows, suspended ceiling, ground and dado decoration and fitment.
The blockboard is generally composed of surface plate, core plate and plate core. Surface plate refers to the surface layer of blockboard, and core plate refers to the single plate layer between the surface plate and the plate core, which is a plywood or wood lattice structural plate composed of strips of wood, and is the most intermediate layer of blockboard.
According to the use environment of blockboard, blockboard is divided into indoor blockboard and outdoor blockboard, general blockboard and construction blockboard according to the use, three layer blockboard, five layer blockboard and multi-layer blockboard according to the number of layers, and blockboard is divided into Class E0 blockboard, Class E1 blockboard and Class E2 blockboard according to the formaldehyde release rating.
Key indicators
Formaldehyde. According to the national standards, the formaldehyde release limit of blockboard shall be no more than 0.5 mg/L for Class E0, no more than 1.5 mg/L for Class E1, and no more than 5.0 mg/L for Class E2. The disqualification of blockboard sold on the market at present mainly involves two aspects: one is the excessive formaldehyde release, which poses a threat to human health; Second, some products, although formaldehyde emissions in E2 level, did not reach E1 level, but marked E1 level, which is also ineligible.
Lateral static bending strength. Lateral bending strength and bonding strength, reflecting the ability of blockboard products to carry loads and resist stressed deformation. There are three main reasons for the disqualification of lateral bending strength. One is that the raw material itself is defective or decayed, and the core material is not good; Second, in the production process, the patching technology did not reach the standard; Third, did not do a good job of glueing.
Glue strength. Gluing properties mainly have three process parameters, time, temperature and pressure. And how to use more and less adhesive, also affect formaldehyde release indicators.
Water content. Water content is an indicator that reflects the moisture content of blockboard. If the moisture content is too high or uneven, the product will appear warping or non-uniformity during use, affecting the product's service performance.
Options Hint
One is to look at the appearance. The surface shall be dry to the touch, smooth and free from defects. The entire plate shall be flat and warped, the corners shall be straight when placed upright, the diagonal error shall not exceed 6 mm, and the entire stack (package) shall be placed with complete fit between each plate; Marks shall be complete.
The second is to look sideways. The thickness of the core plate can be observed from the side or the cut off end surface to see if it is even, straight, overlapping, or out of joint, to see if the material to be filled in is dense, if the joints between the battens are tight, and to see if there are cracks and obvious gaps and decayed and deteriorated battens at both ends of the core battens. At the same time, it also depends on whether there is glue or putty around.
The third is measuring the size. Measure the size of the blockboard, and in particular measure if the thickness of the blockboard agrees with the nominal thickness.
The fourth is to measure the glued quality. Interceptable 75 mm × After the 75 mm test pieces were put into 63 ° C water and boiled for 3 hours, the glue layer on each end face of the test piece was observed to see if there was glue opening. Generally, the glue layer of the blockboard with good quality would not appear glue opening.
The fifth is to check the environmental protection performance. Stacking unused blockboard in a cabin with doors and windows closed for indoor observation after 24 hours of storage. If there is no obvious pungent odor, the formaldehyde release of the schedule blockboard is less, and the use will not affect human health; If the smell is greater or there is a sense of tears, indicating that the blockboard may have a higher formaldehyde release, it should be sent to the relevant departments for testing.
Six is the price comparison. Generally speaking, E1 grade blockboard price should be above 100 yuan, the price of E0 grade blockboard should be above 130 yuan. If the price is too low, a quality issue should be considered
