Professional Solutions for Cratering Issues Caused by Chemitech Coating Defoamers

The addition of defoamers is a common practice to eliminate foam in coating production. However, some users report cratering issues in  coatings after defoamer application, affecting appearance and performance. This article analyzes the causes and provides solutions.  

Root Causes of Cratering  

1. Poor compatibility: Mismatch between defoamer and coating system causes uneven surface tension.  

2. Overdosing: Excessive defoamer (>0.5%) disrupts film leveling.  

3. Inadequate mixing: Localized high concentration due to insufficient dispersion.  

Solutions  

1. Select compatible defoamers: Chemitech offers high-performance options (e.g., KM-220) – conduct lab tests before full-scale use.  

2. Optimize dosage: Maintain 0.1%-0.5% dosage based on coating viscosity.  

3. Improve mixing: Use low-speed agitation (300-500 rpm) for uniform distribution.  

Preventive Measures 

- Perform compatibility tests prior to application.  

- Avoid operation under high temperature/humidity.  

- Regularly clean equipment to prevent contamination.  

By implementing these methods, cratering defects in Chemitech coatings can be minimized. For technical support, contact Chemitech’s official team.