Formaldehyde mainly exists in urea-formaldehyde resin-based adhesives, and wood-based panels such as MDF, particleboard and plywood are mainly used in furniture. The manufacturing process of this kind of board is simply to treat wood into sawdust, then add adhesive and process sawdust into board through high temperature extrusion. Formaldehyde exists in the adhesive.

Urea and formaldehyde are mixed together and polymerized under the catalysis of acid or alkali. The traditional process will add 1.5 to 2 times of formaldehyde to ensure the product grade. Due to the high viscosity of urea-formaldehyde resin, a large amount of unreacted formaldehyde will be mixed into the whole system after the reaction, which is the free formaldehyde that causes the harm of decoration formaldehyde.

You may have such a question: formaldehyde is so harmful, why not use urea-formaldehyde resin glue? Can't you replace it with something else? This is also the direction that green chemistry and chemical industry are trying to solve the problem of formaldehyde pollution in decoration-the substitute of urea-formaldehyde resin glue, but there is no good result yet.

1, the key reason is that the production cost of urea-formaldehyde resin is very cheap.

Not only raw materials-urea and formaldehyde, these two basic chemical products are quite cheap, and urea-formaldehyde resin has formed a mature industrial chain. And the inertia of traditional industries is also a big problem. Once a certain production process is determined, it is difficult to turn around in a short time. Other products are difficult to compete with urea-formaldehyde resin in cost. Compared with urea-formaldehyde resin, the cost of new products is dozens or even hundreds of times higher.

2. Secondly, the performance of formaldehyde as an adhesive is not bad.

The most traditional three kinds of aldehyde-containing resins are urea-formaldehyde resin, phenolic resin and melamine-formaldehyde resin, among which urea-formaldehyde resin is the lightest (the color of phenolic resin is darker after curing, which is very important for decoration adhesive), and the uncured urea-formaldehyde resin can be well mixed with water, with fast curing speed and good bonding strength. It is also a practical way to develop a new production process of urea-formaldehyde resin with low free formaldehyde content. Although there are many achievements, it is still impossible to fundamentally shake the position of urea-formaldehyde resin in adhesives.