Fire resistant panels made from wood chips - which are mixed with boron mineral and inorganic acid, then dried and impregnated with synthetic resin before hot pressing

摘要

The wood chips are mixed with a boron mineral and a stoichiometric amt. of H3PO4 or H2SO4; and the reaction prod. is possibly treated with a soln. of alkali silicate before drying. The prod. is next impregnated with a binder based on formaldehyde resin, and a hydrophobic agent is added before the mixt. is pressed into panels. The initial mixt. pref. contains 100 pts.wt. wood chips and 10-300 pts.wt. boron mineral, to which H3PO4 contg. 15-65 wt.% P2O5, or H2SO4 contg. 20-70 wt.% acid is added. The hydrophobic agent is pref. an oil, grease, dissolved wax, or a polymer soln. Panel can be made which meet class B1 of DIN4102, i.e. very resistant to combustion.