Eliminating Winter Exudation in PVC Synthetic Leather with DB55

Eliminating Winter Exudation in Synthetic PVC Leather Using DB55

How do you stop winter exudation in synthetic PVC leather? Winter exudation is plasticizer bleeding to the surface when a compound is exposed to cold and humid conditions, and it is driven by plasticizer-resin compatibility rather than by the plasticizer loading alone. DB55 was developed for artificial leather and automotive interiors with a soft hand feel and a clearly improved direction for oil exudation in cold and humid conditions.

What winter exudation actually is

Exudation, often called bleeding or blooming, is the migration of plasticizer to the surface of the article until it forms an oily film or a visible bloom. In synthetic leather it appears as greasy spots, print loss, blocked rolls after storage and a change in hand feel. In automotive interiors it contributes to windscreen fogging and to complaints about surface appearance.

Cold and humid conditions accelerate the visible failure for two reasons. First, the solubility of the plasticizer in the PVC matrix decreases as temperature falls, so a fraction of the plasticizer becomes thermodynamically surplus. Second, humidity and condensation on the surface change how the exuded film appears, which is why customers notice the problem in winter rather than in summer.

Why loading alone does not explain the failure

Two compounds with the same plasticizer loading and the same Shore A hardness can behave differently in a winter storage test. The difference is normally one of these factors:

1. Plasticizer-resin compatibility. A plasticizer operating close to its compatibility limit will exude once the temperature drops.
2. Formulation balance. Excess filler, an unbalanced lubricant package or a stabiliser 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 article.
4. Finished-article storage. Film or roll stored under compression at low temperature shows exudation first at the contact points between layers.

This is why a winter exudation complaint is a formulation and processing problem, not simply a question of reducing plasticizer content.

DB55 profile for artificial leather and automotive interiors

DB55 targets artificial leather and automotive interior applications. Formulation confirmation against the target vehicle or finished-product standard is recommended, because the acceptance criteria differ between interior parts.

Troubleshooting procedure

1. Reproduce the failure under controlled conditions. Store a sample of the current article at low temperature and high humidity for a defined period and record surface appearance, hand feel and mass change. A reproducible test is the basis of every later comparison.
2. Screen compatibility first. Before changing the plasticizer, confirm that the current plasticizer is not already being used above its compatibility limit in that formulation.
3. Move to DB55 in a stepwise way. Prepare a comparison lot with DB55 at the same Shore A target and keep the stabiliser and lubricant packages fixed so that only the plasticizer changes.
4. Check fusion. Confirm that the compound is fully fused on the actual line. Under-fused compound will exude even with a well-selected plasticizer.
5. Re-check 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 and humid storage test on the finished article, including the roll or stack configuration used in storage, and confirm the hand feel and appearance after storage.
7. Lock the specification. Once the DB55 loading is confirmed, record the batch COA reference in the specification so that supply is reproducible.

Frequently asked questions

Does DB55 eliminate winter exudation in every formulation?

No formulation change can promise that for every compound. DB55 provides a clearly improved direction for oil exudation in cold and humid conditions in artificial leather and automotive interior applications, and the result must be confirmed on the specific formulation, processing window and finished-part test.

What causes winter exudation if the plasticizer loading is unchanged?

The usual causes are operating close to the plasticizer compatibility limit, excessive filler, insufficient fusion during processing, or storage under compression at low temperature. The troubleshooting procedure above checks these factors in order.

Can DB55 be trialled without changing other raw materials?

Yes. The recommended approach is to keep the stabiliser and lubricant packages fixed and substitute the plasticizer against the same Shore A target, then compare cold and humid storage behaviour of the two lots.

Support and documentation notice

DOBO New Energy technical materials are provided for engineering evaluation and formulation planning. Final product specifications, TDS and 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 samples for leather trials, please contact our technical sales team through the contact page.