Defoamer for Oil-Based PU in Automotive Coating: Solving Pinholes and Color Shifts

Foam-induced pinholes and pigment dispersion issues are major challenges in oil-based polyurethane (PU) coating for automotive parts. Bubbles generated during mixing or potting disrupt film continuity and cause localized color deviation. Chemi Tech's specialized defoamer achieves optimal foam control through molecular design, balancing rapid bubble rupture and system compatibility.

Technology: Targeted Nano-Carrier Mechanism

Hydrophobic Silicone Particles: Adsorb onto bubble membranes, reducing surface tension to collapse microfoam;

Stability Enhancement: Polar compatibility with PU resins prevents pigment floating or separation.

Case: Dashboard Coating Yield Improvement

An interior parts manufacturer faced 15% pinhole defects and red color shifts (ΔE＞2.0). After applying Chemi Tech's KM-2018 defoamer:

Process Upgrade: 0.5% dosage added at resin premixing stage, cutting dispersion time to 15 minutes;

Defect Control: Pinholes reduced to 0.3%, ΔE stabilized below 0.8 (ISO 11664);

Cost Savings: First-pass yield increased from 70% to 98%, saving ￥120,000 monthly in rework costs.

Applications

Epoxy Flooring: Suppresses microfoam in large-area spreading for smooth surfaces;

Electronic Potting: Eliminates bubbles causing circuit protection failure;

Metallic Paints: Compatible with aluminum flake orientation, preserving metallic effects.

Chemi Tech's dynamic compatibility ensures hydrogen bonding with PU systems, maintaining activity under high-temperature curing (180℃) and shear stress.