Causes of formaldehyde produced by wood-based panels
(1) When the wood itself is dry, formaldehyde is generated due to internal decomposition. The lower the wood density, the stronger the formaldehyde emission ability.
(2) The glue used for the bonding of the board substrate is one of the main reasons for the generation of formaldehyde. The main glues currently on the market are urea-formaldehyde glue and melamine glue.
The production process of urea-formaldehyde glue is simple and does not require high equipment. It is mostly produced by many small workshops, but the formaldehyde emission is large, but because of its low price, it is mainly bonded by wood board, medium and low-density fiberboard. It is used for boards with a large amount of glue.
The melamine glue is a new type of environmentally friendly glue, its production process and equipment requirements are relatively high, the formaldehyde content is low, but the price is much more expensive than urea-formaldehyde glue, generally used for high-end plates.
Environmental standards
The environmental protection detection method of wood-based panels is to use the perforation method to measure the amount of formaldehyde taken out of the panel after a certain number of holes are passed through the panel. At present, the standards referenced by plates on the market are roughly divided into national environmental protection standards and European standards, and their parameters are as follows:
| Test method and limit value of formaldehyde emission in artificial board | ||||
| name | experiment method | limit value | scope of use | |
high density | Perforation extraction | ≤9mg/100g | Can be used directly indoors | E1 |
| ≤30mg/100g | It must be finished and can be used indoors | E2 | ||
| Dryer method | ≤1.5mg/L | Can be used directly indoors | E1 | |
| ≤5.0mg/L | It must be finished and can be used indoors | E2 | ||
| artificial board | Climate box method | ≤0.12mg/m3 | Can be used directly indoors | E2 |
| Dryer method | ≤1.5mg/L | |||
European environmental standards:
Grade E0 The formaldehyde content in each 100g product is ≤5mg (≤5mg/100g)
Level E1 The formaldehyde content per 100g product is ≤5-10mg (≤5-10mg/100g)
Level E2 The formaldehyde content per 100g product is ≤10-30mg (≤10-30mg/100g)