Technical Specifications and Testing Standards for FSC Grey Board Composite Paper
FSC-certified grey board composite paper is a sustainable, high-rigidity packaging material made from 100% recycled pulp and produced under the Forest Stewardship Council's environmental and social standards. Its quality hinges on precise adherence to thickness, gram weight (GSM), and physical properties, which are rigorously tested using international protocols. Below are the key parameters and testing standards governing this material.
Critical Quality Parameters
Thickness and Gram Weight Ranges:
Thickness: Standard grey board thickness spans 0.3 mm to 4 mm, with tolerances of ±0.05 mm for boards <3 mm and ±0.06 mm for thicker variants 258.
Gram Weight (GSM): Typically ranges from 250 to 2600 GSM, with allowable deviations of ±4–5%. For example, a 600 GSM board must weigh between 570–630 GSM to meet compliance 158.
Physical and Structural Standards:
Moisture Content: Must be maintained at 8–12% to prevent warping or softening. Specific grades like double grey board (250–750 GSM) require tighter control (7–9%) 2.
Dimensional Stability:
Size tolerance: ±3 mm for sheet dimensions (e.g., 787 × 1092 mm) 2.
Skewness (diagonal deviation): ≤3 mm 12.
Mechanical Performance: Premium grey board must exhibit high stiffness and folding resistance. When bent at 30°, corners should not delaminate or crack 2.
Surface and Composition Requirements:
Surface Quality: Must be smooth, flat, and free of bubbles, spots, or impurities 2.
Material Composition: Classified into three types:
Single Grey: Grey on one side.
Double Grey: Grey on both sides with a yellow core.
Full Grey: Uniform grey throughout, offering superior strength 28.
Testing Standards and Methodologies
Gram Weight (GSM) Testing: Governed by ISO 536, which specifies gravimetric or area-based methods. Samples are weighed and measured to calculate GSM, with equipment calibrated to ≤0.1% accuracy 9.
Thickness Measurement: Follows GB/T 451.3 (ISO 534), using micrometers under controlled pressure (50 kPa ± 1 kPa) 5.
Moisture Content: Tested via GB/T 462, involving oven-drying samples at 105°C until weight stabilizes 5.
Certifications: Compliant boards carry FSC, ISO, SGS, or ROHS certifications, verifying sustainability, safety, and performance 58.
Quality Control in Manufacturing
Manufacturers implement multi-stage inspections:
Raw Material Checks: Pulp quality and moisture levels 2.
In-Process Testing: Semi-finished product thickness, GSM, and moisture 2.
Post-Production Validation: Random sampling for stiffness, skewness, and surface defects 2. Storage conditions (cool, dry, flat stacking) are critical to preserve integrity 2.
Table: Key Specifications for FSC Grey Board Composite Paper
| Parameter | Standard Range | Tolerance | Test Method |
|---|---|---|---|
| Thickness | 0.4 mm – 5 mm | ±0.05 mm (<3 mm); ±0.06 mm (≥3 mm) | GB/T 451.3 / ISO 534 |
| Gram Weight (GSM) | 250 – 2600 GSM | ±4–5% | ISO 536 |
| Moisture Content | 8% – 12% | ±2% | GB/T 462 |
| Sheet Dimensions | e.g., 787 × 1092 mm | ±3 mm | Manufacturer QC |
| Skewness | - | ≤3 mm | Visual/Measurement |
| Core Composition | Single/Double/Full Grey | - | Visual Inspection |
Conclusion
FSC grey board's performance in packaging (e.g., puzzles, luxury boxes) relies on strict conformity to thickness, GSM, and structural benchmarks. Adherence to ISO, GB, and internal QC protocols ensures consistency, recyclability, and durability. Brands prioritizing eco-friendly materials increasingly specify this board due to its 100% recycled content and compliance with global sustainability standards 258. Manufacturers must maintain rigorous testing across production stages to meet these technical thresholds.
Eric Zhang | Songhong Paper
📱 WhatsApp: +86 189 3351 0249
03@songhongpaper.com
