A highly automated and efficient production line for Fireproof  B-s1, d0  Grade Plywood consists of a series of precision machines, divided into five main sections: Raw Material Processing, Core Impregnation & Drying, Mat Forming & Hot Pressing, Finishing Section, and Auxiliary Systems.

I. Raw Material Processing Section

1.  Log Bucking Saw: Cuts purchased logs into specified lengths required by the peeling lathe.

2.  Log Debarker: Removes bark from logs. Bark lacks fiber and contains impurities that affect peeling quality and bond strength.

3.  Log Steaming Pond/Vat: Softens log sections with hot water or steam to reduce lignin hardness, preventing breakage during peeling and enabling production of continuous, smooth veneer.

4.  Veneer Peeling Lathe: A core machine. Clamps and rotates the softened log against a sharp blade to produce continuous veneer of uniform thickness.

     Key Features: Precision gap control system, dual-spindle design for non-stop feeding, laser scanner for optimizing yield.

5.  Veneer Clipper: Cuts the continuous veneer ribbon into preset widths and lengths, removing defective sections with knots or splits. Often includes automatic stacking.

II. Core Impregnation & Drying Section

6.  Veneer Dryer: Reduces the moisture content of green veneer from ~60% to 8-12% for impregnation and pressing.

      Key Types: Roller dryer (for large sheets), mesh belt dryer (for small pieces, minimizes warpage).

7.  Flame Retardant Impregnation Line: The most critical section for forcing flame retardant solution deep into the veneer fibers.

      Key Components:

          Dip Tank: Large stainless steel tank for the solution.

          Squeeze Rolls: Pairs of rollers that squeeze out air and force liquid into the veneer.

          Vacuum-Pressure Impregnation Tank (High-end): A closed vessel that first pulls a vacuum to remove air from the veneer cells, then applies high pressure (6-10 atm) to force the solution in. Superior to simple dipping.

          Solution Circulation & Concentration Control System.

8.  Secondary Drying Machine: Dries the impregnated veneer at low temperatures (70-90°C) to evaporate moisture and achieve "pre-curing" (surface dry, resin not fully cured), preparing it for hot pressing.

III. Mat Forming & Hot Pressing Section

9.  Glue Spreader: Applies adhesive (e.g., phenolic resin) evenly onto the veneer surfaces before lay-up. Flame retardants can be mixed into the glue.

10. Automatic Layup Line: Automatically assembles veneers (glued and unglued) into a mat with cross-oriented grains according to preset layers.

      Key Components: Robotics, assembly stations, conveyors. Ensures symmetric structure and consistent quality.

11. Pre-press: Applies cold pressure to the assembled mat for preliminary bonding, making it stable enough for transport and preventing it from being blown apart when entering the hot press.

12. Hot Press: The "heart" of the line. Applies high heat (140-180°C) and high pressure (15-25 MPa) to cure the adhesive and resin permanently, bonding the veneers into a board with uniform density, high strength, and certified fire resistance.

      Key Types: Multi-opening hot press (high capacity), continuous flat press (higher efficiency, more uniform board properties).

      Key Features: Precision hydraulic system, heated platens (extremely flat and uniform), automatic loading/unloading system.

IV. Finishing Section

13. Cooling System: Cools the hot boards (>100°C) coming out of the press to room temperature using cooling racks or fans to prevent warping and stabilize internal stresses.

14. Panel Saw / Trimming Saw: Cuts the large cooled panels into standard sizes and trims the irregular edges.

      Key Types: Double-end trim saw, CNC cutting center.

15. Sanding Machine: Sands the top and bottom surfaces for precise thickness calibration and fine finishing. Removes the pre-cured layer and imperfections, preparing the board for laminating, painting, or direct use.

      Key Type: Wide-belt calibrating sander, often with 3 or 4 heads (coarse, fine, finish sanding).

V. Auxiliary & Environmental Systems

16. Waste Gas Treatment System: Treats exhaust gases from dryers and hot presses (containing formaldehyde, phenols, VOCs). Typically uses a combination process like "Cyclone + Scrubber + RTO (Regenerative Thermal Oxidizer)" or electrostatic capture to ensure compliance with environmental regulations.

17. Centralized PLC Automation Control System: The "brain" of the line. Uses PLCs and industrial computers to integrate and control all equipment, monitoring thousands of parameters (temperature, pressure, speed, moisture) in real-time. Ensures precise process execution, fault diagnosis, data logging, production stability, and product consistency.

The classification of fireproof plywood is primarily based on its reaction to fire performance, i.e., how the material behaves in a fire, including its combustibility, flame spread rate, heat release, and production of smoke and toxic gases. Different regions around the world employ different testing standards and classification systems. The following are three major systems:

1. Chinese Standard (GB 8624)

The Chinese National Standard "Classification for burning behavior of building materials and products" GB 8624 is the most common reference, divided into the following grades:

     Class A (Non-combustible Materials): These materials barely burn and represent the highest grade of fireproofing. Typically inorganic materials (e.g., stone, glass, metal), organic polymer boards rarely achieve this class.

      A2: Non-combustible with some requirements for smoke and toxicity.

      Class B1 (Flame-retardant Materials): This is the highest common grade achievable by fireproof plywood. The material itself has excellent flame retardancy, is difficult to ignite with an open flame, stops burning quickly once the ignition source is removed, and has low heat release and potentially low smoke production during combustion.

      Class B2 (Combustible Materials): The grade for standard flame-retardant boards. It will burn when exposed to flame but at a slower rate; combustion slows after the ignition source is removed. Its fire performance is better than untreated ordinary boards (B3) but far inferior to B1.

      Class B3 (Flammable Materials): Ordinary wood and boards without any flame retardant treatment, highly flammable and a significant fire hazard.

2. European Standard (EN 13501-1)

The European standard assesses not only combustibility but also the production of smoke and burning droplets/particles.

  A1, A2 (Non-combustible): Highest grades, unattainable for organic boards.

  B, C, D (Combustible but with flame-retardant properties): These are the primary target grades for fireproof plywood. Performance decreases from B to D.

      The rating is supplemented with smoke and droplet notations (e.g., B-s1, d0):

          Smoke Production (s1, s2, s3): s1= little or no smoke; s2= medium smoke production; s3= high smoke production.

          Burning Droplets/Particles (d0, d1, d2): d0= none; d1= some, short duration; d2= significant.

Therefore, a high-quality fireproof plywood under the European standard might be rated B-s1, d0 or C-s1, d0.

3. American Standard (ASTM E84)

The US commonly uses the ASTM E84 "Steiner Tunnel Test," which primarily evaluates two parameters:

  Flame Spread Index (FSI): Measures the speed at which flames spread across the material's surface. A lower index indicates slower flame spread.

      FSI 0-25: Class A (Excellent)

      FSI 26-75: Class B (Good)

      FSI 76-200: Class C (Pass)

  Smoke Developed Index (SDI): Measures the amount of smoke produced during combustion. A lower index indicates less smoke.

      To achieve Class A, the SDI must be ≤450.

Therefore, a fireproof plywood meeting US Class A must satisfy both the FSI and SDI criteria above.

Fire-rated plywood (primarily referring to Class B1/Flame-retardant grade and above) is widely used in various settings with stringent fire safety requirements due to its excellent flame resistance, structural strength, and relatively light weight. Its main application scenarios can be divided into the following sectors:

1. Commercial & Public Buildings

This is the primary and most extensive application field for fire-rated plywood.

  Large Shopping Malls & Retail Centers: Used for interior finishes such as suspended ceilings, wall linings, partitions, display counters, props, and decorations in safety corridors.

  Hotels & Convention Centers: Used for walls, ceilings, and partitions in guest rooms, corridors, ballrooms, and meeting rooms, meeting both high-end aesthetic demands and strict fire codes.

  Office Buildings: Used for interior fit-outs in high-end office spaces, such as partitions, cabinets, and feature walls.

  Hospitals & Schools: Used for furniture and interior finishes in wards, classrooms, and laboratories. These are densely occupied areas where evacuation is challenging, making fire safety critical.

2. Transportation Sector

  Shipbuilding: Used for interior cabin finishes, furniture, paneling, and ceilings in cruise ships, ferries, and luxury yachts. Must comply with strict International Maritime Organization (IMO) fire standards.

  Railway Vehicles: Used for interior wall panels, partitions, luggage racks, ceilings, and furniture in high-speed trains, subways, and railway carriages.

  Aerospace & Buses: Used for non-structural components and decorative panels in aircraft cabins and bus interiors.

3. Industrial & Infrastructure

  Clean Rooms & Laboratories: Used for wall and ceiling panels in environments with high requirements, such as electronics, pharmaceutical, and food plants, offering a smooth surface and flame resistance.

  Power Stations & Data Centers: Used for server cabinet linings, partitions inside computer rooms, protecting valuable equipment and reducing fire risk.

  Stadiums & Theaters: Used for grandstand flooring, stage backdrops, and decorative elements in highly crowded venues.

4. Other Special Requirement Scenarios

  High-End Residential: Used in villas and apartments seeking higher safety standards for kitchen cabinets, storage units, and interior decorations.

  Safety Corridors & Fire Escapes: Used as lining boards in corridors and stairwells to buy critical time for occupant evacuation.

The core value of fire-rated plywood in these scenarios is its ability to not only meet legally mandatory fire safety standards and building codes but also provide workability, strength, and decorative appeal similar to traditional plywood, achieving a perfect balance between safety and aesthetics.