The production of wood chipboards using low-molar urea-formaldehyde and low-toxic adhesives

The article discusses the production of wood chipboards using adhesives with low formaldehyde content, where the ratio between urea and formaldehyde is within K:F = 1:1.1÷1.12. This, in turn, greatly reduces the content of free formaldehyde, and under the conditions of proper technological process, the toxicity index of the obtained slabs does not exceed the emission group of (E1 E2). In addition, the physical-mechanical properties of the slabs remain within the normal range. In the case of using low molecular resins, hydrolysis is carried out partially or completely due to changes in temperature and humidity during the hardening of resins and adhesives. In this case, hydrolysis destruction is within 20÷25% in the outer layers of the slab, while it does not take place in the inner layers. This greatly reduces the content of free formaldehyde, and, in addition, the toxicity of the slabs is reduced by varying the hardener layer by layer.