Engineered wood boards with reduced VOC emissions

A process for preparing an engineered wood panel comprising the steps of:

• coating wood strands with a first resin wherein the first resin comprises a reaction product of reagents comprising:
• about 5 to about 25 wt % melamine;
• about 5 to about 20 wt % urea;
• about 15 to about 30 wt % formaldehyde;
• and
• water;
• coating wood strands with a second resin which is different than the first resin;
• preparing a wood panel comprising a core layer, and upper and lower surface layers, wherein the surface layers contain about 4 wt % to about 12 wt % of the first resin, and wherein the core layer comprises the second resin.

A wood panel comprising

• a) upper and lower surface layers comprising i) wood strands, ii) a first resin, and ii) about 0 to about 4 wt % of a second resin,
• wherein the first resin is a melamine urea formaldehyde resin which is a condensation reaction product of
• about 5 to about 25 wt % melamine;
• about 5 to about 20 wt % urea;
• about 15 to about 30 wt % formaldehyde;
• about 15 to about 75 wt % water;
• and further condensation reaction with
• about 0 to about 10 wt % phenol compound;
• and
• wherein the second resin is powdered phenol-formaldehyde (PF) resin, and
• b) a core layer comprising i) wood strands and ii) a third resin.

A method for reducing emissions in engineered wood materials comprising

• a) adding a first melamine urea formaldehyde (MUF) resin to wood strands,
• b) adding about 0 to about 4 wt % of a second formaldehyde-containing resin to the first resin or the first resin and wood strands mixture,
• d) adding a third resin to wood strands,
• d) forming an engineered wood material using each of the resin/wood strands mixtures,
• wherein the first resin and third resin are different and wherein the first resin/wood strands mixture is used in surface layers of the engineered wood material and wherein the third resin/wood strands mixture is used in a core layer of the engineered wood material.