| 摘要 |
The hard slab according to the invention contains formaldehyde, the content of which is at most 30 mg/kg per dry slab. For manufacturing it, a material based on wood in a powdery form is brought to a given water content, the particles are mixed with an internal impregnation agent, this mixture is provided, at least in a subsequent operating step, with a binder based on a synthetic resin for hardening the mixture, this mixture is poured out in the shape of a cake and is compressed under heat, the binder based on synthetic resin being added, partially or exclusively, in the form of a urea-formaldehyde condensate having a free formaldehyde content of up to 2.8% by weight with respect to the dry matter. Manufacture of slabs for floor surfacing.
|
