Plywood Door Manufacturing Process

Factory 1: Door Plywood Facing

Log Preparation
- Logs are loaded into steaming basins for 3 days.
- Purpose: De-ices logs in winter and softens wood fiber.
Debarking Process
- Steamed logs are lined up for debarking.
- Operator uses a laser for precise centering of the log on the debarker.
- Importance of positioning:
  - Minimizes wood loss when removing bark.
  - Ensures logs are perfectly cylindrical for maximum veneer yield.
Rotary Cutting
- Logs spin on a lathe to skim off sheets of veneer (0.6 mm thick).
- Average yield: 134 linear meters of veneer per log.
Veneer Processing
- Veneer sheets are unrolled and cut into sheets.
- Sheets are stacked by identical grain patterns.
- Visual defects are removed using a laser-guided blade.
- Veneer sheets for the front of the door are aligned in mirror image; defects are used for the back.
Plywood Assembly
- Use of three veneer sheets:
  - Glue applied to both sides of one sheet, sandwiched between two others.
  - Hot press at over 100°C cures glue in 1.5 minutes, forming a three-ply panel.
Sanding
- Panel is sanded after curing.
- Variety of wood species used: birch, oak, maple, mahogany, etc.

Core Assembly
- Strips of wood are glued to form the core.
- Framed with white pine pieces.
Pressing Process
- A press consolidates core pieces and activates glue using microwaves instead of heat.
Calibrating and Sanding Core
- Core is sanded and calibrated after gluing.
Final Assembly
- Plywood door facing is adhered to both sides of the core.
- Stacked in a cold press for 30 minutes until glue dries.
- Curing process takes an additional 8 hours.

Sizing and Shaping
- Doors are sized to final dimensions, edges beveled, height cut precisely.
Inspection
- Doors are inspected from both sides.
Preparation for Hardware
- Machines prepare doors for hinges and cut knob holes.
Finishing Process
- Takes 70 seconds per door.
- One side sanded, stained, sealed, sanded again, and varnished; then flipped for the other side.