Treatment of formaldehyde-containing wood panel products
OwnerDavid W. Parkinventor
Life of this patent
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Abstract
A process for treating wood panels is disclosed where the panels are placed in a closed treatment chamber and the chamber then evacuated. This removes free formaldehyde from panel pores and produces a subatmospheric pressure within the pores. The chamber is then pressurized with an ammonia and air mixture with ammonia in the mixture permeating the panel pores and reacting with free formaldehyde. The chamber is then evacuated to recover unreacted ammonia.
Claims10
A process for treating a porous formaldehyde-containing wood panel to control formaldehyde emissions from the panel comprising:
- placing the panel in a chamber and with closing of the chamber evacuating the chamber to establish a subatmospheric pressure therein, with the evacuation removng atmospheric gases from the chamber and gases from the pores of the panel including free formaldehyde and further producing a subatmospheric pressure within these pores,
- then introducing gases ammonia into the evacuated chamber and with such introduction establishing a superatmospheric pressure therein, and with the superatmospheric pressure established permeating the panel pores with ammonia and reacting ammonia with a residual formaldehyde to convert the formaldehyde to a relatively stable hexamine residual.
The process for treating a porous formaldehyde-containing wood panel to control formaldehyde emissions therefrom comprising:
- placing the panel in a chamber and after closing of the chamber evacuating the chamber to establish a vacuum therein of at least about 20" Hg, with the evacuation removing atmospheric gases from the chamber and gases from the pores of the panel including free formaldehyde and producing a subatmospheric pressure within these pores,
- then introducing a gseous ammonia and air mixture into the chamber to establish by such introduction a superatmospheric pressure therein, the ammonia and air mixture containing from 26% to 45% ammonia, and with the superatmospheric pressure estalbished permeating the panel pores with ammonia and reacting ammonia with residual formaldehyde to convert such into a relatively stable hexamine residual, and after introduction of the ammonia and air mixture in a subsequent evacuation evacuating the chamber to remove ammonia not reacted with formaldehyde.
A process for treating formaldehyde-containing porous wood panels to control formaldehyde emissions therefrom which comprises:
- establishing within a chamber a stack of the panels with the panels in the stack spaced from each other and with the space between adajcent panels communicating with the chamber interior and after establishing the stack closing the chamber,
- evacuating the closed chamber to establish a vacuum therein, with the evacuation removing atmospheric gas from the chamber interior and from between the panels and gas from the pores of the panels includng free formaldehyde and producing a subatmospheric pressure within these pores,
- introducing gaseous ammonia into the evacuated chamber and with such introduction establishing a superatmospheric pressure in the chamber, with the superatmospheric pressure established permeating the panel pores with ammonia and reacting ammonia with residual formaldehyde to convert such to a stable hexamine residual within the panel, and
- following the introduction of the ammonia establishing a vacuum within the chamber to remove ammonia not reacted with formaldehyde.
Dependencies are inferred from the claim text.