The application describes a method of scavenging formaldehyde from a wooden composite comprising urea-formaldehyde or melamine urea-formaldehyde by providing a combination of formaldehyde scavengers in the face and core layers of the composite and further describes the composite produced with these scavengers.

A formaldehyde free adhesive composition and a plywood obtained by the adhesive composition is provided, and the plywood retains desired performances, such as water resistance and workability.

The present invention relates to a formaldehyde-free medium-high-density board capable of meeting deep facing requirements, and a method for manufacturing same. The method includes: wood chipping, screening, cooking and softening, fiber separating, gluing, drying and sorting, paving, pre-pressing, hot pressing, cooling, sanding, and inspection and warehousing, where the gluing is two-step gluing, including: first performing gluing once by using a lignin adhesive, and then performing secondary gluing by using an MDI adhesive after waterproof treatment. According to the manufacturing method of the present invention, by using biomass adhesives and formaldehyde-free adhesives without adding additives such as a curing agent and an anti-mildew agent, formaldehyde pollution is eliminated from the source by using a two-step gluing method, so that production is formaldehyde-free, and the product is formaldehyde-free. Through the sequential control of the gluing process and the grasp of the gluing type and ratio, surface hardness of the product is improved, and the final product is capable of deep facing to reach 20 to 80 filaments.

A novel green manufacturing process for medium and high-density fiberboard (MDF and HDF) production is disclosed, where the green manufacturing process refers to a novel low-emitting manufacture of MDF and HDF in terms of HAP emission. The novel manufacturing process comprises a preconditioning unit operation for raw wood furnish material, where blends comprising two or more woody materials having disparate moisture contents are held in a preconditioning vessel for up to 48 hours under controlled temperature conditions, where the moisture content is homogenized to produce a blend having substantially uniform moisture content. The blend is preconditioned in the novel manufacturing process to facilitate moisture homogenization kinetics, and to uniformly increase the material temperature above the lignin glass transition temperature. Subsequent process steps, such as defibration and fiber drying, require lower temperatures to produce and dry wood fiber, thus lowering HAPs emission.

The invention is directed to a process for the manufacture of composite wood structures, which provides for increased production rates and machinability. More particularly, the process comprises combining wood particles with a composition comprising an aqueous protein and diluent dispersion.

It is provided a process to modify lignocellulosic materials with lignin, and incorporating lignin and isocyanates or other wood adhesive in wood products compositions, and their composition, preparation and application for bonding wood products are disclosed. The compositions comprise lignin, derived from a variety of natural resources, isocyanate compounds containing two or more isocyanate functional groups, or other wood adhesives.

A formaldehyde free adhesive composition and a plywood obtained from the adhesive composition is provided, and the plywood has a balanced performance, such as high adhesion strength, sufficient pot-life, and good workability.

A fire-resistant wooden pressure plate is formed by conducting a cold pressing of 2˜10 MPa to the uniformly mixed not less than 50 wt % of a wood-containing powder material and an additive. The additive may include metallic oxide, non-metallic oxide, hydrochloride, sulfate, phosphate, weak acid, and strong acid. With class-A fire resistance, in-water rotting resistance, class-0 mold resistance, little or no detectable formaldehyde, some products described herein can replace traditional plates incapable of resisting fire in the following fields: 1. wooden veneer, wooden door, furniture, kitchenware, etc.; 2. wooden wall, base course, ground foundation, suspended ceiling, etc.; 3. wooden flooring; 4. wooden fire-resistant door, fire-resistant wall, etc.; 5. wooden house, wooden bench, wooden bulletin plate, wooden billboard, walkway paving, etc.; 6. wood handicrafts, toys, etc.

In one embodiment, a method for making a high density structural composite includes depositing a plurality of fibrous materials on or adjacent a first plate or surface. A polymer liquid is deposited onto the plurality of fibrous materials to form a composite mixture. A first cyclic pressure is applied onto the composite mixture to compress the composite mixture. In some embodiments, the cyclic pressure may then be reduced to a valley pressure to complete a pressurization cycle. In some instances, the valley pressure may be below atmospheric pressure to induce trapped air and volatile gases to escape from the composite mixture before curing. The pressurization cycle may be repeated. A second pressure, which may be a constant pressure in some embodiments, may be applied to the composite mixture using, in some embodiments, a second plate until the polymer liquid has at least partially cured or partially solidified.

Composite cellulosic products and processes for making same. In some embodiments, the composite cellulosic product can include a plurality of cellulosic substrates and an at least partially cured binder. Prior to curing, the binder can include a mixture formed by combining magnesium oxide, water, and magnesium chloride. A weight ratio of the magnesium oxide to the magnesium chloride in the binder can be at least 2.2:1 to 8.5:1.