Pigment flooding and floating are common defects primarily caused by imbalanced pigment movement. Sunmun Technology provides systematic, customized solutions that address the root causes, ensuring uniform color distribution, stability, and consistent film quality.
Problem Overview
Pigment flooding (separation in the can) and floating (non-uniform film appearance) result in streaks, mottling, or color shift. These defects originate from physical and chemical imbalances within the coating system, driven by:
- Surface tension mismatch between colorants and the base paint.
- Hydrophilic-lipophilic imbalance affecting pigment wetting.
- Pigment property variations in density, particle size, and flocculation tendency.
- Internal convective flows (e.g., Bénard cells) during film formation.
Root Cause Analysis
Surface Tension Differential & Bénard Cells
During drying, solvent evaporation creates surface tension and temperature gradients, triggering internal circulation (Bénard cells). Pigments with differing mobilities separate within these flows, leading to uneven distribution—visible as flooding on horizontal surfaces and floating on vertical surfaces.
Differential Pigment Mobility
Variations in pigment density, particle size, surface treatment, and resin compatibility cause pigments to move at different speeds and directions. This mobility differential is the core mechanism behind pigment separation.
Role of Additives: Wetting Agents vs. Silicones
- Silicone-based additives primarily modify surface tension to suppress Bénard cell formation but do not fully address pigment mobility differences.
- Wetting and dispersing agents adsorb onto pigment surfaces, improve compatibility, reduce flocculation, and directly control pigment movement—making them essential for resolving floating and flooding at the root.
Sunmun Technology’s Solution Framework
We deliver system-based diagnostics and tailored formulations, not just standalone products.
Comprehensive System Evaluation
Our technical team works with you to review:
- Your base paint formulation (resin, additives, solvent balance).
- Application process and environmental conditions.
- Color paste properties (surface tension, compatibility, stabilization).
Customized Formulation Adjustment
- Core strategy: Selection or customization of high-performance wetting and dispersing agents to balance pigment mobility and enhance colorant-base compatibility.
- Supportive measures: Integration of silicone or surface-control additives to manage flow and leveling without interfering with pigment stability.
Lab Validation & Performance Confirmation
We conduct simulated tests (draw-downs, spray-outs, stability trials) to verify solution effectiveness. Process parameters and dosing guidelines ensure reproducible results.
The Sunmun Partnership Value
- Deep expertise: We understand the behavior of each pigment and color paste in complex systems.
- Extensive experience: Our practical expertise enables precise problem diagnosis and effective solutions.
- End-to-end partnership: From analysis to validated solutions, we help improve your first-pass yield, reduce waste, and strengthen competitiveness.
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