Se-Igbo
Sejavane
Sekannada
Sekazakh
- Sekhmer
- Sekurdi
- Se-kyrgyz
- Selatine
- Selatvia
- Selithuania
- Luxembou..
- Semacedonia
- Semalagasy
- Semalay
Semalayalam
Semalta
- Maori
- Semarathi
- Semongolia
- Seburmese
- Senepali
- Senorway
- Sepashto
Sepersia
- Sepunjabi
- Seserbia
Sesotho
Sesinhala
- Se-Slovak
- Seslovenia
- Sesomali
- Sesamoa
- Se-Scots Gaelic
- Seshona
- Sesindhi
- Sesundanese
- Seslovenia
- Seswahili
- Se-Tajik
- Setamil
- Setelugu
- Sethai
- Seukraine
- Se-Urdu
- Se-Uzbek
Sevietnam
Sewelshe
Sexhosa
Seyiddish
Seyoruba
- Sezulu
- Sekinyarwanda
- Se-Tatar
- Se-Oriya
- MaTurkmen
- Se-Uyghur
- Antimony: Sb₂O₃ (to be removed).
1. Recommended Formulation Framework (per 100 phr PVC resin)
| Component | Function | Loading (phr) | Notes |
|---|---|---|---|
| PVC Resin | Base polymer | 100 | Medium/high molecular weight for balanced processing/properties. |
| Primary Plasticizer | Softness | 40–60 | Option A (Cost/Performance Balance): Partial phosphate ester (e.g., RDP/BDP, 10–20 phr) + DOTP/DINP (30–50 phr). Option B (Low-Temperature Priority): DOTP/DINP (50–70 phr) + efficient P-N flame retardant (e.g., ADP, 10–15 phr). Goal: Match original softness. |
| Primary Flame Retardant | Flame retardancy, smoke suppression | 30–50 | Surface-treated MDH or MDH/ATH blend (e.g., 70/30). High purity, fine particle size, surface-treated. Adjust loading for target flame retardancy. |
| P-N Synergist | High-efficiency flame retardancy, char promotion | 10–20 | Choice 1: High-temp APP (Phase II). Choice 2: ADP (higher efficiency, lower loading, higher cost). Choice 3: Phosphate ester plasticizers (RDP/BDP) – adjust if already used as plasticizers. |
| Synergist/Smoke Suppressant | Enhanced flame retardancy, smoke reduction | 5–15 | Recommended combo: Zinc borate (5–10 phr) + zinc stannate (3–8 phr). Optional: MoO₃ (2–5 phr). |
| Ca/Zn Stabilizer (HICOAT-410) | Thermal stability | 2.0–4.0 | Critical! Slightly higher loading may be needed vs. Sb₂O₃ formulations. |
| Epoxidized Soybean Oil (EPOXY) | Co-stabilizer, plasticizer | 3.0–8.0 | Retain for stability and low-temperature performance. |
| Lubricants | Processing aid, mold release | 1.0–2.5 | ST (stearic acid): 0.5–1.5 phr. BZ-500: 0.5–1.0 phr (adjust based on function). Optimize for high filler loadings. |
| Processing Aid (e.g., ACR) | Melt strength, flow | 0.5–2.0 | Essential for high-filler formulations. Improves surface finish and productivity. |
| Other Additives | As needed | – | Colorants, UV stabilizers, biocides, etc. |
2. Example Formulation (Requires Optimization)
| Component | Type | Loading (phr) |
|---|---|---|
| PVC Resin | K-value ~65–70 | 100.0 |
| Primary Plasticizer | DOTP/DINP | 45.0 |
| Phosphate Ester Plasticizer | RDP | 15.0 |
| Surface-Treated MDH | – | 40.0 |
| High-Temp APP | Phase II | 12.0 |
| Zinc Borate | ZB | 8.0 |
| Zinc Stannate | ZS | 5.0 |
| Ca/Zn Stabilizer | HICOAT-410 | 3.5 |
| Epoxidized Soybean Oil | EPOXY | 5.0 |
| Stearic Acid | ST | 1.0 |
| BZ-500 | Lubricant | 1.0 |
| ACR Processing Aid | – | 1.5 |
| Colorants, etc. | – | As needed |
Critical Implementation Steps
- Confirm Raw Material Details:
- Clarify the chemical identities of
BZ-500andST(consult supplier datasheets). - Verify exact loadings of
DOP,EPOXY, andHICOAT-410. - Define client requirements: Target flame retardancy (e.g., UL94 thickness), softness (hardness), application (automotive, furniture, bags?), special needs (cold resistance, UV stability, abrasion resistance?), cost limits.
- Clarify the chemical identities of
- Select Specific Flame Retardant Grades:
- Request halogen-free flame retardant samples tailored for PVC leather from suppliers.
- Prioritize surface-treated ATH/MDH for better dispersion.
- For APP, use high-temperature-resistant grades.
- For phosphate esters, prefer RDP/BDP over TCPP for lower migration.
- Lab-Scale Testing & Optimization:
- Prepare small batches with varying loadings (e.g., adjust MDH/APP/ZB/ZS ratios).
- Mixing: Use high-speed mixers (e.g., Henschel) for uniform dispersion. Add liquids (plasticizers, stabilizers) first, then powders.
- Processing Trials: Test on production equipment (e.g., Banbury mixer + calendering). Monitor plastification time, melt viscosity, torque, surface quality.
- Performance Testing:
- Flame retardancy: UL94, LOI.
- Mechanical properties: Hardness (Shore A), tensile strength, elongation.
- Softness/hand feel: Subjective + hardness tests.
- Low-temperature flexibility: Cold bend test.
- Thermal stability: Congo red test.
- Appearance: Color, gloss, embossing.
- (Optional) Smoke density: NBS smoke chamber.
- Troubleshooting & Balancing:
| Issue | Solution |
|---|---|
| Insufficient flame retardancy | Increase MDH/ATH or APP; add ADP; optimize ZB/ZS; ensure dispersion. |
| Poor mechanical properties (e.g., low elongation) | Reduce MDH/ATH; increase P-N synergist; use surface-treated fillers; adjust plasticizers. |
| Processing difficulties (high viscosity, poor surface) | Optimize lubricants; increase ACR; check mixing; adjust temps/speeds. |
| High cost | Optimize loadings; use cost-effective ATH/MDH blends; evaluate alternatives. |
- Pilot & Production: After lab optimization, conduct pilot trials to verify stability, consistency, and cost. Scale up only after validation.
Conclusion
Transitioning from antimony-based to halogen-free flame-retardant PVC leather is feasible but requires systematic development. The core approach combines metal hydroxides (preferably surface-treated MDH), phosphorus-nitrogen synergists (APP or ADP), and multifunctional smoke suppressants (zinc borate, zinc stannate). Simultaneously, optimizing plasticizers, stabilizers, lubricants, and processing aids is critical.
Keys to Success:
- Define clear targets and constraints (flame retardancy, properties, cost).
- Select proven halogen-free flame retardants (surface-treated fillers, high-temp APP).
- Conduct rigorous lab testing (flame retardancy, properties, processing).
- Ensure uniform mixing and process compatibility.
More info., you can contact lucy@taifeng-fr.com
Post time: Aug-12-2025
