Eliminating Winter Exudation in PVC Synthetic Leather with DB55

Eliminating Winter Exudation in Synthetic PVC Leather with DB55

How to prevent winter exudation in synthetic PVC leather?Winter exudation occurs when plasticizers migrate to the surface of a compound under cold, humid conditions. This phenomenon is driven by plasticizer-resin compatibility, not just plasticizer loading. DB55 was developed for artificial leather and automotive interiors, offering a soft hand feel and significantly improved resistance to oil exudation in cold, humid environments.

What winter exudation actually is

Exudation, often referred to as bleeding or blooming, occurs when plasticizers migrate to the surface of a product, forming an oily film or visible haze. In synthetic leather, this manifests as greasy spots, loss of print clarity, blocked rolls after storage, and changes in texture. In automotive interiors, it contributes to windshield fogging and customer complaints regarding surface appearance.

Cold, humid conditions accelerate visible failure for two reasons. First, as temperature drops, the solubility of the plasticizer in the PVC matrix decreases, causing a portion of it to become thermodynamically surplus. Second, surface humidity and condensation alter the appearance of the exuded film, which is why customers typically notice this issue in winter rather than summer.

Why loading alone doesn't explain the failure

Two compounds with identical plasticizer loading and Shore A hardness may exhibit different performance in a winter storage test. The difference typically stems from one of the following factors:

1. Plasticizer-resin compatibilityA plasticizer operating near its compatibility limit will exude when the temperature drops.
2. Balanced formulation.Excess filler, an unbalanced lubricant package, or a stabilizer system that is insufficient for the residence time can increase surface migration.
3. Processing history.Insufficient fusion leaves poorly solvated plasticizer that behaves as free liquid in the finished product.
4. Finished goods storage.Film or roll stored under compression at low temperature exhibits exudation first at the contact points between layers.

This is why winter exudation issues stem from formulation and processing challenges, not merely from reducing plasticizer content.

DB55 profile for artificial leather and automotive interiors

DB55 targets artificial leather and automotive interior applications. We recommend confirming the formulation against the target vehicle or finished-product standard, as acceptance criteria vary by interior part.

Troubleshooting steps

1. Reproduce the failure under controlled conditions.Store a sample of the current article at low temperature and high humidity for a defined period, then record surface appearance, hand feel, and mass change. A reproducible test is the foundation for all subsequent comparisons.
2. Prioritize screen compatibility.Before switching plasticizers, verify that the current one is not already used beyond its compatibility limit in this formulation.
3. Move to DB55 step by step.Create a comparison lot with DB55 at the same Shore A target, keeping the stabilizer and lubricant packages constant so that only the plasticizer varies.
4. Verify fusion.Ensure the compound is fully fused on the actual line. Under-fused compounds will exude even with a well-selected plasticizer.
5. Recheck the filler level.Excessive filler increases the free plasticizer fraction that can migrate to the surface. Reduce filler before increasing plasticizer content.
6. Validate at the finished part level.Repeat the cold, humid storage test on the finished product using the same roll or stack configuration as in storage. Verify hand feel and appearance after storage.
7. Lock the specification.Once DB55 loading is confirmed, record the batch COA reference in the specification to ensure reproducible supply.

Frequently asked questions

Does DB55 prevent winter exudation in all formulations?

No formulation change can guarantee this for every compound. DB55 offers a clearly improved direction for oil exudation in cold and humid conditions for artificial leather and automotive interior applications; however, results must be confirmed through specific formulations, processing windows, and finished-part testing.

What causes winter exudation if the plasticizer loading remains unchanged?

Common causes include operating near the plasticizer compatibility limit, excessive filler content, insufficient fusion during processing, or storage under compression at low temperatures. The troubleshooting steps above address these factors in order.

Can DB55 be trialed without modifying other raw materials?

Yes. We recommend keeping the stabilizer and lubricant packages unchanged, substituting the plasticizer to match the same Shore A target, then comparing cold and humid storage performance between the two batches.

Support and documentation notice

DOBO New Energy technical materials are provided for engineering evaluation and formulation planning. Final product specifications, TDS, SDS documents, batch certificates of analysis, packaging configurations, and regulatory statements are validated per specific commercial order.

For grade inquiries, technical data sheets, and 1 kg leather trial samples, please contact our technical sales team via the Contact page.