How to distinguish the quality of WPC?
WPC (Wood–Plastic Composite) quality can be judged by looking at materials, structure, performance, and manufacturing details. Here’s a practical, step-by-step way to distinguish high-quality vs low-quality WPC, whether for decking, panels, doors, or boards.
1. Check Raw Materials (Most Important)
✔ High-quality WPC
Uses virgin HDPE or PP (not recycled mixed plastics)
Wood fiber/flour is fine, dry, and uniform
Contains UV stabilizers, anti-oxidants, and coupling agents
✘ Low-quality WPC
Made with mixed recycled plastics (smells bad when cut)
Wood powder contains impurities or moisture
Lacks additives → fades, cracks, or becomes brittle
🔍 Tip: Ask for a material composition sheet or test report.
2. Look at Surface & Color
✔ High-quality
Smooth or evenly textured surface
Uniform color throughout
No visible white spots, bubbles, or streaks
✘ Low-quality
Patchy color
Rough, chalky surface
Visible pores or pinholes
🔨 Scratch test: Scratch lightly—good WPC won’t show white plastic underneath.
3. Density & Weight
Higher density = better strength
Light boards often mean too much plastic or fillers
📏 Typical good WPC density:
1.25–1.4 g/cm³ (varies by application)
4. Strength & Flexibility Test
✔ High-quality
Slight flexibility without cracking
Returns to shape after bending
Holds screws firmly
✘ Low-quality
Cracks when bent
Brittle edges
Screws loosen easily
🧪 Simple test: Press or bend a sample—listen for cracking sounds.
5. Water Resistance Test
Immerse a piece in water for 24–48 hours
✔ Good WPC
Minimal swelling (<1%)
No delamination
No surface whitening
✘ Poor WPC
Swells noticeably
Surface becomes rough or soft
6. Fire & Heat Resistance
High-quality WPC:
Self-extinguishing
No dripping molten plastic
Poor WPC:
Burns fast
Strong plastic odor
🔥 Ask for fire-retardant grade if used indoors.
7. UV & Weather Resistance (Outdoor Use)
✔ Good WPC
Color fading ≤ 5–8% after 1000–2000 hours UV test
No surface cracking
✘ Poor WPC
Fades quickly
Becomes brittle within 1–2 years
📄 Request UV aging test reports (ASTM G154 / EN standards).
8. Manufacturing Process
✔ High-quality
Extruded under controlled temperature
Co-extrusion (protective outer layer) for outdoor products
Clean, precise cuts
✘ Low-quality
Inconsistent thickness
Rough edges
Voids inside the profile
9. Smell Test
Good WPC → no strong smell
Bad WPC → burnt plastic or chemical odor
10. Certifications & Warranty
Look for:
ISO 9001
CE / ASTM / EN standards
5–15 year warranty (outdoor WPC)