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Views: 0 Author: Site Editor Publish Time: 2025-08-15 Origin: Site
Selecting the best polyester polyol foam for spraying involves evaluating several key factors to ensure optimal performance, adhesion, insulation, and durability. Here’s a step-by-step guide to help you judge:
Cream Time, Gel Time, Tack-Free Time: The foam should have a balanced reactivity profile suitable for spraying:
Cream time: 3–7 seconds (allows proper mixing and application).
Gel time: 10–25 seconds (ensures quick curing without sagging).
Tack-free time: <60 seconds (for faster recoating or handling).
Compatibility with Isocyanate (PMDI): Ensure the polyol blends well with polymeric MDI for a smooth reaction.
Density: Typically 25–50 kg/m³ (1.5–3.0 lb/ft³) for spray foam applications.
Higher density (≥30 kg/m³) improves strength and adhesion.
Closed-Cell Content: ≥90% for better insulation (lower water absorption & higher R-value).
Compressive Strength: ≥200 kPa (29 psi) for structural durability.
Dimensional Stability: Should resist shrinkage or expansion under temperature/humidity changes (test per ASTM D2126).
R-value: ≥6.0 per inch (0.025 W/m·K) for good insulation.
Long-term Thermal Resistance (LTTR): Verify through aging tests (e.g., CAN/ULC S770).
Substrate Bonding: Test adhesion on concrete, metal, wood, etc. (ASTM D1623).
Spray Pattern: Should be uniform, without drips or voids.
Viscosity: Low enough for easy spraying (typically 1,500–3,000 cP at 25°C).
Flame Spread & Smoke Development (ASTM E84):
Class I (flame spread ≤25, smoke ≤450) preferred for building codes.
Fire Resistance: Check for certifications (UL, FM Approvals).
VOC Content: Low volatile organic compounds (meets EPA/LEED standards).
Blowing Agent: HFO-based (e.g., Solstice® LBA) for low GWP vs. older HFCs.
Isocyanate Emissions: Should comply with OSHA/ACGIH limits.
Quality Consistency: Reliable supplier with batch-to-batch uniformity.
Certifications: UL, ICC-ES, CE, or other regional approvals.
Technical Support: Availability of datasheets, SDS, and application guides.
Spray Trials: Test in real conditions (humidity, temperature effects).
Aging Tests: Assess long-term performance (water resistance, UV stability if exposed)
| Parameter | Target Value |
|---|---|
| Reactivity | Cream: 3-7s, Gel: 10-25s |
| Density | 30-50 kg/m³ |
| Closed-Cell Content | ≥90% |
| R-value | ≥6.0 per inch |
| Adhesion Strength | ≥20 psi (ASTM D1623) |
| Fire Rating | Class I (ASTM E84) |
| VOC Content | Low (meets LEED/EPA) |
By evaluating these factors, you can select the best polyester polyol foam for your spraying application, balancing performance, safety, and cost. Always conduct small-scale tests before full deployment.
