Formaldehyde-free medium-high-density board capable of meeting deep facing requirements and method for manufacturing same

A method for manufacturing a formaldehyde-free medium-high-density board capable of meeting deep facing requirements, comprising:

• (1) wood chipping:
• cutting a wood raw material into wood chips that meet the production scale;
• (2) wood screening:
• screening the wood chips in step (1) to remove debris, and separating oversized wood chips for further shredding;
• screening the shredded wood chips to remove the debris, and separating the oversized wood chips for further shredding;
• (3) cooking and softening:
• after screening, cooking and softening wood chips in step (2);
• (4) fiber separating:
• putting the wood chips in step (3) into a defibrator and separating fibers mechanically;
• (5) primary gluing:
• performing primary gluing adhesive on the fibers in step (4), where the primary gluing adhesive is a lignin adhesive;
• (6) waterproof treatment:
• performing waterproof treatment on the fibers in step (5) after the primary gluing in step (5), and adding paraffin wax;
• (7) secondary gluing:
• performing secondary gluing adhesive on the fibers in step (6) to obtain gluing fibers, where the secondary gluing adhesive is a MDI adhesive;
• (8) drying and sorting:
• feeding the gluing fibers in step (7) to a drying system for drying;
• (9) paving pre-pressing:
• paving the gluing fibers in step (8) into a slab by using a paving machine;
• (10) hot pressing forming:
• delivering the slab to a hot pressing machine by using a loader, for pressing into a rough board;
• (11) board turning cooling:
• feeding the rough board in step (10) into a board turning machine for cooling, stacking and curing, to a plain board;
• (12) sanding polishing:
• after sanding, the plain board in step (11) is sawed to a board of the required size;
• (13) inspection and warehousing:
• grading and packaging the board in step (12) according to the quality standard requirements, for warehousing;
• and
• (14) downstream processing:
• in floor processing enterprises, facing decoration is performed on the board in step (13);
• the formaldehyde-free medium-high-density board capable of meeting deep facing requirements is capable of implementing 20-80-filament deep facing;
• the lignin adhesive comprises components with the following weight percentages:
• lignin 20% to 45%;
• sodium hydroxide 2.0% to 8.5%;
• melamine 2% to 8%;
• polyvinyl alcohol 0.2% to 1.0%;
• urea 2% to 6%;
• and
• water 40% to 70%.