1. Formaldehyde. According to national standards, the formaldehyde emission limit for blockboard using the climate chamber method is E1 ≤ 0.124 mg/m³. The non-compliance of blockboard sold on the market with formaldehyde emission standards mainly involves two aspects: first, the formaldehyde emission exceeds the standard, posing a significant threat to human health; second, some products, although their formaldehyde emission is within the E2 level, do not reach the E1 level, yet are labeled as E1. This is also considered non-compliant.
2. Transverse Static Bending Strength. Transverse static bending strength and bonding strength reflect the ability of blockboard products to bear loads and resist deformation under stress. The main reasons for non-compliance in transverse static bending strength are threefold: first, defects or decay in the raw materials themselves, resulting in poor core quality; second, substandard splicing techniques during production; and third, improper gluing.
3. Bonding Strength. Bonding performance mainly involves three process parameters: time, temperature, and pressure. The amount and method of adhesive use also affect the formaldehyde emission index.
4. Moisture Content. Moisture content reflects the moisture content of the plywood. If the moisture content is too high or uneven, the product may deform, warp, or become uneven during use, affecting its performance.