After 300 CONTAINERS inspection yearly ,our qc team shared their inspection experience below :
PVC foam board is a versatile material widely used in construction, advertising, and interior design due to its lightweight, durability, and ease of fabrication. This report compares the production processes, material compositions, common defects, and laboratory test results of PVC foam boards manufactured in Vietnam and China. Additionally, it evaluates the quality of boards exported to the United States and their applications.
Production Processes and Techniques
Vietnam:
Vietnamese manufacturers typically employ a two-step extrusion process for PVC foam board production. The first step involves mixing PVC resin, calcium carbonate (CaCO₃), stabilizers, foaming agents, and modifiers in a high-speed mixer. The mixture is then extruded through a twin-screw extruder, where it undergoes expansion under controlled temperature and pressure. Vietnamese production lines often prioritize cost efficiency, leading to higher filler content (up to 30-35% CaCO₃), which may impact mechanical strength.
China:
Chinese manufacturers utilize advanced single-step extrusion technology with precise temperature and pressure control. The raw material mix includes higher-quality PVC resin (K-value 65-68), lower filler ratios (20-25% CaCO₃), and specialized foaming agents (e.g., AC foaming agent) for uniform cell structure. Automated production lines ensure consistent thickness and density, while post-production calibration rollers enhance surface smoothness.
Key Differences in Raw Materials and Formulations
- PVC Resin: Chinese boards use higher-grade resin with better thermal stability, while Vietnamese products often rely on mid-grade resin to reduce costs.
- Fillers: Vietnamese boards contain more CaCO₃ (30-35%), slightly reducing impact resistance. Chinese formulations limit fillers to 20-25% for improved strength.
- Additives: Chinese manufacturers incorporate UV stabilizers and anti-aging agents for outdoor applications, whereas Vietnamese boards may lack these enhancements unless specified.
Common Quality Defects
- Vietnam: Surface roughness, uneven foaming (density variations), and edge warping due to inconsistent cooling. Some batches show poor interlayer bonding.
- China: Rare but occasional issues include minor surface scratches from calibration rollers or slight color deviations due to pigment dispersion.
Laboratory Test Data
Test samples from both countries were evaluated for density, tensile strength, impact resistance, and flame retardancy (ASTM D1621, D638, D256, and E84 standards).
- Density: Vietnamese boards averaged 0.55-0.60 g/cm³; Chinese boards achieved 0.50-0.55 g/cm³ with better uniformity.
- Tensile Strength: Chinese samples outperformed (18-22 MPa) versus Vietnamese samples (14-17 MPa).
- Flame Retardancy: Both met Class B standards (ASTM E84), but Chinese boards exhibited lower smoke density.
Comparative Quality of Finished Products
Chinese PVC foam boards demonstrate superior dimensional stability, surface finish, and mechanical properties due to tighter process controls and premium additives. Vietnamese boards are more cost-effective but may require stricter quality checks for high-precision applications.
Export Quality Analysis for the U.S. Market
PVC foam boards exported to the U.S. must comply with ASTM standards and CARB Phase II regulations for formaldehyde emissions. Chinese exports often dominate the mid-to-high segment (e.g., signage, architectural moldings) due to their consistency and UV-resistant formulations. Vietnamese boards are commonly used in budget-friendly interior applications (e.g., exhibition stands, furniture backing).
Conclusion
While China’s PVC foam boards lead in technical performance, Vietnam offers competitive pricing for less demanding uses. U.S. importers should select suppliers based on application requirements, prioritizing Chinese products for outdoor or structural uses and Vietnamese alternatives for cost-sensitive projects.
Recommendations
- Vietnamese manufacturers should invest in advanced extrusion technology to reduce density variations.
- Chinese producers could further optimize pigment dispersion to eliminate minor color inconsistencies.
- U.S. buyers must verify CARB compliance and request third-party test reports for critical projects.
