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        # Solving the Winter Crack: Why PVC Soles Fail in Cold Climates

        

**Topic:** Footwear

        

It's the middle of winter. Your customers are returning shoes because the soles are snapping like glass. Your brand reputation is on the line.

        
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## Problem

Standard PVC formulations become brittle as temperatures drop. If the plasticizer migration is high or the glass transition temperature (Tg) isn't sufficiently lowered, the sole loses its flexibility. This is especially common when using low-quality recycled resins or insufficient secondary plasticizers.

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## Likely cause

This issue often stems from inconsistent compounding temperatures, inferior raw material purity, or unbalanced stabilizer ratios within the formulation matrix.

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## Corrective direction

The key is a balanced blend of NBT DOP and specialty low-temperature plasticizers like DOA. Additionally, incorporating NBT ESBO as a secondary plasticizer improves the overall flexibility and prevents migration. Our technical team recommends a specific PHR ratio that keeps soles flexible down to -15°C.

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          ## Frequently Asked Questions

          
### Will more plasticizer make the sole too soft?

Yes, if not balanced. You need the right combination of primary and secondary plasticizers to maintain hardness while improving cold-flex.

### Is DOTP better than DOP for footwear?

DOTP offers better migration resistance, which can help in long-term durability, though DOP is often preferred for its cost-performance ratio in general footwear.

        
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By NBT Technical Desk · Updated 2026-06-07

        

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