Vacuum/pressure impregnation adds fire retardant chemicals deep into the wood's cellular structure.
Vacuum/pressure processes are always industrial and refine the fireproofing properties of the wood. This means that the board itself constitutes both the surface layer and the cladding without the need for additional protective layers such as fireproofing paint. A vacuum-pressure impregnation process should not be compared with simpler methods of flame retardant treatment of the wood surface such as flow coating, spraying, or dipping.
Keyword: Fire impregnation (not available). Instead, terms to look for are impregnation and vacuum and pressure impregnation respectively. Worth knowing is that these concepts often refer to wood preservatives, even though the process of fire impregnation is based on the same principle.
- Impregnation: the treatment of solids with chemicals in liquid or vapour form that penetrate and partially remain in the material.
- Pressure impregnation: impregnation where the wood preservative is pressed into the wood through excess pressure.
- Vacuum impregnation: an industrial impregnation process where the active agent is absorbed into the material using a vacuum.