Syneresis is the separation of a liquid phase from a paint system. To investigate it, compare fresh and stored samples and review the full formulation, not just its initial viscosity. A rheology modifier that reaches the fresh-batch target does not, by itself, prove long-term storage stability.
Syneresis, settling or viscosity drift?
Record what you observe before assigning a cause: a separated liquid layer, sediment, a change in measured viscosity, or several changes together. These observations describe the problem but do not independently identify the ingredient responsible. Photograph the sample and retain the batch and storage records.
How do rheology modifiers relate to storage stability?
BYK’s architectural-coating guidance discusses rheology options for specific formulation systems, including anti-settling and anti-syneresis behaviour. The selection remains system-specific. Chemistry labels such as HEUR or HASE do not establish that every product in the category will perform identically.
What should a storage comparison record?
Use the laboratory protocol appropriate to the product, and record:
- The reference formulation and the one variable intentionally changed.
- The mixing procedure and initial measurement conditions.
- Storage time, temperature and packaging conditions.
- Viscosity measured under comparable conditions and the observed separated layer or sediment.
- Redispersibility and relevant application properties after storage.
This is a record-keeping framework, not a universal accelerated-ageing temperature or pass/fail limit. The product specification and validated laboratory method determine the conditions.
Which formulation details matter before selecting a modifier?
Provide the binder system, current rheology package, relevant surfactants, pH information and the production and storage history available to the technical team. Review the proposed additive’s TDS and recommended incorporation procedure. BYK’s rheology range illustrates why product selection needs more than a chemistry name.
Does an additive shelf life establish the paint shelf life?
No. An additive’s own storage statement applies to that product under its specified conditions. It is not a storage-stability result for a finished paint containing it. Establish the finished product’s performance from testing of the actual formulation.
What is the next step for a separation problem?
Keep the observation, test conditions and formulation context together before changing dosage or additive type. Review rheology modifiers or describe the paint system and storage observations to discuss a specific case.
Content updated:
