Pine preservative plywood is a core product for outdoor and humid environment applications, with the following application scenarios:

Construction Formwork: High-strength formwork for concrete pouring, requiring water resistance and multiple reuses

Roofing Structures: Roof sheathing and attic flooring, needing protection against moisture and fungal decay

Outdoor Landscaping: Park facilities, outdoor furniture, trellises exposed to natural elements

Dock and Marine Facilities: Dock decking and marina structures in contact with fresh or saltwater

Agricultural Buildings: Livestock shelters, greenhouses, and other humid/corrosive environments

Pine (especially radiata pine) is the primary raw material for preservative plywood worldwide, due to its straight grain, excellent workability, and superior bonding performance. With the growth of outdoor timber construction and infrastructure development, demand for properly treated pine plywood continues to rise.

The pine preservative treated plywood production line covers the complete process from logs to finished treated panels:

1. Log Preparation → Pine log cross-cutting and debarking

2. Steaming/Softening → High-temperature softening for improved peeling quality

3. Veneer Peeling → Peeling pine logs into continuous veneer ribbons

4. Veneer Drying → Reducing moisture content to 8-12% to prevent deformation

5. Veneer Grading & Patching → CCD inspection, grading, automatic plugging/splicing

6. Gluing & Layup → Using waterproof phenol-formaldehyde (PF) resin, cross-grain layup in odd layers

7. Cold Pre-Pressing → Air exhaustion and initial mat shaping

8. Hot Press Forming → High temperature and pressure curing adhesive to form plywood panels

9. Trimming & Sanding → Edge trimming to standard sizes, calibrating sanding

10. Preservative Treatment (Core Process) → Vacuum-pressure preservative impregnation

11. Curing & Conditioning → Preservative stabilization and panel performance conditioning

12. Quality Inspection & Grading → Testing preservative retention and penetration depth per AS/NZS standards

13. Packaging & Warehousing → Finished product packaging, ready for shipment

Vacuum-Pressure Preservative Treatment Retort

The signature equipment of this production line. Loads sanded pine plywood into sealed treatment retorts for vacuum-pressure impregnation. Process sequence includes: initial vacuum (removing air from wood cells) → preservative solution injection → pressure impregnation (1.0-1.5MPa, forcing preservative into wood fibers) → final vacuum (recovering excess preservative). Retorts are constructed of corrosion-resistant stainless steel with automatic level and pressure controls.

 Preservative Mixing & Circulation System

Includes preservative concentrate storage tanks, mixing tanks, working solution tanks, circulation pumps, and filtration units. This system dilutes preservative concentrate to working solution at precise ratios, circulating between retorts and tanks for efficient reuse and minimal chemical waste. Equipped with automatic proportioning control with concentration accuracy of ±0.1%.

Curing & Conditioning Area

After preservative treatment, plywood panels require placement in a controlled temperature and humidity environment for sufficient fixing of preservatives within the wood. Curing time is generally 24-72 hours, maintaining ambient temperature at 20-40℃ with protection from direct sunlight and rain.

Automatic Stacking & Packaging System

Automatically sorts and stacks quality-approved panels by grade, wrapping with stretch film, adding edge protectors, and securing with strapping bands to form shipping-ready packaging units suitable for long-distance sea freight.

Thermal Oil Heater or Steam Boiler

Provides heat source for hot presses and dryers. Options include coal-fired, oil-fired, gas-fired, or biomass-fired boilers based on customer's fuel availability, offering high thermal efficiency and stable operation.

PLC Central Control System

The central nervous system of the entire production line. Provides centralized control and real-time monitoring of all equipment parameters including temperature, pressure, time, and speed via touch screen. Features fault self-diagnosis alarm and remote monitoring interface for intelligent production management.

1. Integrated Full-Process Design: Complete coverage from log peeling to finished preservative treatment, reducing intermediate losses and coordination costs

2. International Standard Treatment Process: Vacuum-pressure impregnation technology ensuring deep preservative penetration

3. Multiple Preservative Compatibility: Flexible switching between ACQ, CCA, Boron, MCQ and other preservative systems for different export market requirements

4. High-Quality Pine Plywood: Waterproof phenol-formaldehyde resin adhesive and strict hot pressing process ensuring superior bond strength and water resistance

5. High Automation Level: PLC fully automatic control reducing labor dependence and ensuring product consistency

6. Turnkey Service: One-stop support from equipment installation, process commissioning to operator training