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Home / News / Industry News / Waterborne Paint Settles During Storage — Where to Start with Anti-Settling Agent?
Industry News
Waterborne Coatings · Anti-Settling · Anti-Sagging · DH-6930S
Waterborne coatings in practical application frequently face two simultaneous problems: pigments and fillers gradually settle during storage; and after application to vertical surfaces, the wet film may flow downward due to strong fluidity. These two problems look different but both relate to the rheological state of the coating. Simply raising overall viscosity to address settling may compromise spray feel, spreading, and leveling — the better approach is to manage thixotropic structure, creating a system that holds structure at rest but flows readily under application shear.
Pigment and Filler Settling During Storage
When the liquid system lacks sufficient structural support, solid particles with density higher than the continuous phase gradually accumulate at the bottom during long static periods — especially in high-pigment-content formulations.
Sagging After Application to Vertical Surfaces
After spraying onto a vertical surface, the wet film is subject to gravity. If the coating lacks sufficient low-shear structure after application shear is removed, it flows downward and forms sagging runs.
Thickener Addition Affects Other Properties
Simply increasing thickener to address settling often raises overall viscosity more than necessary, compromising application feel, flow speed, and film surface appearance.
Waterborne Metallic Coatings Are More Sensitive
In waterborne metallic coatings, aluminium flake orientation is affected by the flow process during application. If the rheological structure changes, in addition to settling effects, aluminium flake arrangement and the final metallic effect may also be affected.
Why Anti-Settling Design in Waterborne Systems Requires Thixotropic Thinking
A thixotropic rheological structure has the characteristic that the material behaves differently when at rest and when subjected to shear. At rest, some structure is needed to help pigments and fillers maintain suspension and reduce the tendency for the wet film to flow downward. When equipment stirs or spraying is performed, the structure needs to open appropriately so the coating flows normally. Therefore, evaluating whether an anti-settling agent is appropriate cannot only observe settling after static standing — it must also assess application viscosity, leveling, sagging, and re-dispersibility after storage.
DH-6930S: Waterborne Anti-Settling Agent
DH-6930S is a waterborne anti-settling agent primarily used for rheological structure adjustment in waterborne coatings — applicable for anti-settling and anti-sagging formulation development. In waterborne metallic coatings it can also be tested in combination with aluminium flake arrangement state.
In use, preparing a 20%–30% pre-gel first, then adding to the coating is recommended. Pre-gel preparation can use a high-speed disperser at approximately 1500 RPM for 20–30 minutes. The disperser disc position should be managed during processing to minimise air incorporation. Addition level can be gradient-tested according to formulation conditions, with a reference range of 0.5%–5.0%. DH-6930S is recommended for use at pH ≥ 8.
Anti-settling and anti-sagging in waterborne coatings is not simply a matter of making the paint denser. What truly needs attention is how the material's rheological state changes across static standing, stirring, and application. Formulation adjustment can progressively test thixotropic structure, addition ratio, dispersion method, and pH. For waterborne metallic coatings, aluminium flake arrangement, gloss, and film state can be additionally evaluated alongside anti-settling and anti-sagging performance.
Frequently Asked Questions
Why is pre-gel preparation recommended rather than direct addition for DH-6930S?
DH-6930S forms its rheological network by dispersing and swelling in the aqueous phase — a process that requires adequate energy input and water contact to develop fully. Adding directly to a complete coating formulation gives less control over the dispersion quality and may result in an incompletely developed gel structure, reducing effectiveness or causing inconsistency between batches. Pre-gel preparation at 20–30% concentration ensures the additive is fully activated before incorporation into the coating, giving more consistent and reproducible rheological results.
Does DH-6930S provide any improvement for coatings stored in warm environments where settling accelerates?
Yes — the thixotropic structure that DH-6930S builds helps resist the accelerated settling that occurs at elevated storage temperatures, because the structural network provides more resistance to particle movement than viscosity alone. However, elevated temperature also accelerates the breakdown of any rheological structure over time. Accelerated storage testing at 40–50°C is advisable to assess the performance of the formulation under warm storage conditions before confirming shelf life claims for products stored in warm climates or warehouses.
